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HP Solve: Issue 19 (June 2010)

1. New user registration Forgot password Forgot user ID About HP Passport HP Passport new user registration HP Passportis a single login service that lets you register with HP Passport enabled Web sites using a single user identifier and password of your choice Required field Sign in information User ID Password Confirm password Personal information Title Mr Ms First name Middle name Last name E mail address Preferred language Country Region of residence HP Privacy policy hpCalcFan Minimum characters letters numoers and soecisl characters ooweeee Minimum characters letters numoers snd soecis characters eo Mr Doe johndoe noname com E mail sddress must be different for sach user ID English v United States v Occasionally HP communicates information on products services and or suppor that may be relevantto you This may include new product information special offers or possibly an invitation to participate in market research Before you choose visit our Online Privacy Statement to learn how we use automatic data collection tools and your personal information to tailor your communications Step 4 Sign in using HP Passport Contact HP HP Passport New user registration Forgot password Forgot user ID About HP Passport HP Solve 19 Page 73
2. HP Solve 19 Page 37 Page 1 of 4 Today an HP 41CX outfitted with a AdvHepax Finance Games and Sandbox module implemented in a modern MLDL device called Nov64 is a faithful companion on my desk where it solves three purposes First its high quality and familiar interface it was chosen by NASA as backup computer on board the space shuttles helps me to solve day to day problems easily and quickly like calculating bps spreads from two prices where you only want to type in the significant digits rather than the whole number The first crude version of this program Fig 2 One of the first commercially available took less than 90 seconds to write Eventually I made it MLDL s was produced by the Dutch company more comfortable to use with hotkeys alpha prompts and 7amco It provided 24k space for EPROMs and now use it almost daily You ll also find SCATGO in 8k of RAM into which the user could write my CAT 1 Scattergories which I wrote to play this COD using ERAMCO S operating system fun game and to help me with my English and knowledge of US pop culture a task that seems futile at times Second the HP 41 and its community is a constant source of puzzles and challenges to keep my grey cells busy be that solving math challenges that fellow members post or writing new programs in MCODE like the Spigot program that calculates 5000 digits of TT see http www hpmuseum org cg sys cgiwrap hpmuseum archv019
3. D Card reader connector board At the lower end of the calculator highlighted in red are the keyboard PCB to logic PCB connector pins The yellow highlight at the bottom end of the card reader connector board indicates the position of the card reader connector board to logic PCB connector pins These pins are gold plated as are the contact holes in the logic PCB These can suffer poor contact or corrosion To remove the logic PCB follow these steps 1 Gently lift up the card reader connector board at the yellow highlighted end The gold plated contact pins will separate from corresponding holes 10 the logic PCB 2 Now using a pry tool of some type preferably not metal lift the logic PCB away from the top shell using the red highlighted area as the pry point 3 The logic PCB will separate completely as seen in Figure 7 Clean the contact points highlighted in yellow in Figure 7 as well as the pins on the top shell extruding from the keyboard and the card reader connector board HP Solve 19 Page 26 Page 4 of 13 Continuing further into the calculator requires the removal of six more screws the round dots in Figure 6 To access the top mid and lower right screws require you to gently move the lower end of the card reader connector board to the right Since the screws and logic PCB are now removed the entire mid section of the calculator can be separated from the top shell A note here the keyboard PCB 1s attached to the top of the
4. HP Passport sign in E HF Passport single sign in service lets you use one user ID and password of your choice to sign in to all HP Passport enabled Web sites Required field Sign in to HP Passport User ID Password hpCalcFan eeecese CO Remember my UserID on this computer New users please register E HP Passport is secure Signin Page 3 of 4 Step 5 Fill in information about your HP calculator if you own one and Click Register This should take you 10 the following page Contact HP Calculators site All of HP US HP Calculator Club HP Calculators amp calculata Welcome to the HP Professionals Calculator Club Educators Students Now you can have access to fun and useful member Related links exclusive benefits Register your product Register for information Email us with comments or Reseller locator questions Press releases Support HP Calculator Fonts Calculators Support includes retired models Contact HP Learn how easy itis to create rie sere custom aplets using formulas and equations to help you learn or create e lessons for your class Here you will also find aplets created just for you and ready to download With these HP Calculator fonts you can create learning modules and other teaching tools The possibilities are endless PC Mac screensavers amp backgrounds HP Calculato
5. By using this method the overlay avoids being creased or crimped As with the HP 65 label we will remove any crease but if they are not there in the first place then that is less work at the reassembly procedure Now that the label has been removed you will see the reason 10 the following set of figures and accompanying explanation This calculator as you have discovered has no screws Compare that to the HP 65 which has fifteen if you include the card reader motor Instead we have discovered HEAT STAKES There are four under the _ overlay Figure 17 and four in the battery compartment Figure 18 The heat stakes along with some clips built into the plastic case on the sides holds the calculator together To separate and yet preserve 4 the heats takes we will carefully shave off the extreme top surface Fig 16 Less than 45 degrees to the using a sharp 11 64 inch drill bit Starting with the battery vertical compartment take the drill bit in your hand no need for a drill here Fig 17 Four heat stakes under overlay Fig 18 Four heat stakes in battery compartment Place the drill bit over the top of the heat stake and gently shave off some of the heat stake Remove very little as it is better to go back and shave off more then to overdo the drilling and ruin the heat stake Repeat on the other three stakes Now using a knife insert it between the top shell and the lower shell as indicated in Figure 19 Twist the knife gen
6. LOGS TRIG PLOT SOLY CUST 00 D US GEE i USER PREY NEXT gt Eo P 2 lt 1 m Figure 2 A proposed clamshell calc with HP28 functionality on the right and full touchscreen on the left Starting in the mid 1990s Sebastien Carlier s emu48 49 program for the PC appeared and was later adapted to the Pocket PC PDAs running the Windows CE operating system With its keyboard markup language KML users had the freedom to choose any calculator keyboard layout or image which could range from an actual photo of the machine to a line drawing Keys would be mapped to x and y pixel positions within the KML file After the HP49 version was developed my favorite keyboard image was a modified key layout which restored the ENTER key s size and position back to the HP48 arrangement as shown in figure 3 HP Solve 19 Page 43 Page 2 of 5 Casey s HP48 Sx Graphic pattersc gulttel com T GRAPH 20 20 Wa po LFS HE ffl A ail http www gulftel com pattersc win48 hiii i fot tt 00000 m T i ERREEN END EE 00 APPS MODE w i FRINT 110 MEMORY RART RE UFDIR Cory 191 RIA hh TVAR J STO gt NENT eii n CAD UNDO PROG cline nTRM UP re ALT E TUR YEY SWAF HIST Ma CAT iii Oi EQUATION MATRIK f ENTER SR ENTRY 0 Q are ARITH cOMT oa ON cance Figure 3 An example emu48 image file left and modified emu49 image file right both for th
7. Then press Pram 1 moe Enters program edit mode and displays the first line of the program which will be blank as shown at right since this is a new program Then press the keys needed to access the function in the menu ma or These key presses will access the inverse sine function INPUT in the Math menu The next step would be step 5 leew This key press enters a STOP command This command ends program execution and returns control to the user Press to scroll through the steps of the program which should look like those shown below Mach Tn Pe i Down InPuk Skoff E To exit program edit mode press f This returns the HP 30b to the program catalog and now displays Prgm 1 The number of bytes used by Prgm 1 is shown below it in the display The automation program uses 6 bytes of memory and has a checksum of 047 To assign this program to the am key position enter the program catalog by pressing ugg Press to view step 0 of this program where the key assignment will be entered To assign this program to the 7 key position press 7 The display should appear as shown below SH7 stands for shift hold 7 which is the shift hold sine function position HP Solve 19 Page 6 Page 3 of 7 SH7 m uw Press to exit the program edit mode and return to calculation mode Assuming the calculator is in the degrees angle mode calculate the sine of a 25 degree
8. Calculators Accessories amp Services Quote courtesy of Joel Gaines mathematics teacher South San Antonio Independent School District HP Solve Newsletter Previous Article Next gt Interested in Joining the HP Calc Club and Receiving HP Solve our Free Bi monthly Calculator Newsletter As amember of the HP Calculator Club you will have access to HP Discounts and Special Offers as well as to free applications applets for your HP calculator You will also receive our bi monthly calculator newsletter which is full of helpful tips and learning activities for professionals educators and students It only takes a few minutes to sign up Follow the instructions listed below use the detailed instructions on the next page Step 1 Go to www hp com calculators and click on the link that says Newsletters on the right hand side of the page under the Calculator Community Step 2 The following page will tell you a little bit about the HP Calculator newsletter and prompt you to click the link that says Click Here to Sign UP Step 3 Fill out the HP Passport form Passport allows you to enter all HP passport enabled websites with one universal username and password Think of it as a simple secure portal to HP It also allows you to choose what information you wish to receive from HP and how you would like to receive it 16 e mail postal mail or phone or not at all Passport is the HP way of ensuring that y
9. HP United States English Other ways Customer 6000 00 Financial Calculator Graphing amp Scientific Calculator r P Information for Professionals Educators Students Customers outside the US select your country Calculator community Calc Club Newsletter calculators Calculator support forum What is RPN Save time and keystrokes Learn more O iaveanrt More ways to buy Leasing amp Financing Find a reseller Other ways to buy lick here t discounts by e mail ign Helpful resources Learn amp Use Support amp Drivers Sian up update email month s issue of HP Solve for limited time product discounts HP Solve 19 Page 72 Page 2 of 4 Receive the HP Solve newsletter automatically every even numbered month Get access to special Want to learn how HP can help you easily teach a math concept improve your success in business or explore the features of your calculator that will save time in engineering or surveying Check out this Step 3 Fill out The HP Passport form as shown below Passport allows you to access all HP passport enabled websites with one universal username and password Think of it as a simple secure portal to HP It also allows you to choose what information you wish to receive from HP if any and how you would like to receive it ie e mail postal mail or phone Contact HP O HP Passport Back
10. Separating the halves Fig 22 Top shell Fig 23 Shielding and piezo transducer Examine the top shell the central large framed CPU 1s visible as 19 the 7K memory chip at the lower end of the logic PCB Just to the right of the CPU is a quartz crystal for logic timing purposes With reference to Figure 24 the yellow highlighted dots indicate the position of six tabs bent to hold the logic PCB in place The tabs will line up with slots 10 the logic PCB when Sete This will allow the logic PCB to separate from the top shell exposing the keyboard PCB and foam pressure pad remember that s why we are doing this Now gently straighten the tabs in a direction opposite to the factory bend in effect reverse the direction of the bend done at the factory Bend them back 90 degrees and not forward 90 degrees This varies on who at the factory bent them in the first place The tabs are strong but they were not meant to be twisted Too much bending will fatigue them and if one breaks you end up with a very nice set of spare parts for another calculator I have separated them as much as six times in repair attempts so they will take it but who Fig 24 Yellow tabs knows what the fatigue point is seven consecutive bends back and forth Suffice to say we are trying to fix this at one go with no need to remove the logic PCB again HP Solve 19 Page 31 Page 9 of 13 You may need the knife to gently pry the logic PCB away from the top shell
11. Two divided numbers that form a remainder that that does not repeat or terminate are called irra tional numbers See N9 below Some fractions result in a decimal number that repeats a series of digits These are called repeating deci mals Examples are 1 7 0 14285 71428 571 with 6 repeating digits immediately after the decimal point 1 17 0 05882 35294 11764 70588 23529 411760 with 16 repeating digits starting in the hun dredths place 1 19 0 05263 1578 9 47368 42105 26315 78947 36842 10 with 18 repeating digits Note that the last two examples would not be noticed as repeating decimals on your average calculator Many high end scientific and graphing calculators have functions that separate the integer and decimal parts of a number These functions are especially useful when formatting and converting numbers into various forms See N8 below N6 Real Numbers In computing a real number often refers to non complex floating point numbers In practical mathematics vs number theory the real numbers include both rational numbers such as 42 and 23 129 and irrational numbers such as e and V2 or a real number can be given by an infinite deci mal representation such as 2 48717 73339 where the digits continue 10 some way or the real numbers may be thought of as points on an infinitely long number line N7 Being Consistent Not all number users are consistent This may be confusing and some people say that
12. a SHOW display mode If 35 million or any number is in the display you may also press the left shifted SHOW key see figure nine to display Fig 9 HP35s SHOW the full precision of the number in the machine The SHOW key must be held down to display the view This display mode makes maximum use of the display and may or may not show the decimal point Ta ble four shows how selected number examples will appear in the HP35s display using each of its four dis play modes plus SHOW The high end graphing models have an additional display mode called standard It is similar to ALL Table 4 Example Numbers Shown in Each Display Mode Plus SHOW Number amp Getting SHOW 123 45678910 3 123 457 1 235E2 123 5E0 123 3456789 1 123 3456789100 2 71828182846 5 2 71828 2 71828E0 2 71828E0 2 71828182846 2 71828182846 3 3 14159265359E 4 4 0003 3 1416E 4 314 16E 6 3 14159265359E 4 314159265359 0 121869343405 9 0 121869343 1 218693434E 1 1218 693434E 3 1 21869343405E 1 121869343405 0 000000765532 7 655E 7 765 5E 9 7 65532E 7 765532000000 indicates that the number exceeds the width of the display and the display must be shifted to the right with the right cursor key i 2 71828182846E 6 4 2 7183E 6 2 7183E 6 2 7183E 6 2 71828182846E 6 271828182846 Numbers may be represented in various ways For example a 15 1x3x5 showing the factors of 15 b 15 3 5 15 using the asteri
13. at making this come true might be to install multiple HP calculator emulators onto a touchscreen device such as one of the recently popular smartphones In fact now that Hewlett Packard has made it own Voyager series 12C 15C emulators available on the iPhone the entire concept has been further legitimized However for those of us who prefer to feel the tactile feedback of real keys this solution is far from optimal Touchscreen HP Calculator Proposals Through The Years The idea of an HP calculator operating on a touchscreen device is by no means new in fact an early proposal of such a device appeared in the PPC Journal back in 1984 when suggestions were being solicited for the never implemented PPC44 club project This one shown in figure la suggested a l An old idea to solve the problem of keyboard space versus dispiay space fighting each other for property on such a 51001 surface area the entire top surface or perhaps most of it is a touch sensitive capacitive ala digitizers Screen over an LED dot matrix Perhaps a numeric keynad could remain as real keys below this screen TOUCH SENSITWE a tcd PANEL 20 LINES x 24 CHARS DoT ADDRESSABLE PORTS FORAANENT KEYS NUMERIC KEYPAD ON OFF OTHER MODES ETc Figure la above From PPC Journal VIINIP42 Proposed hardware layout for PPC44 machine in early 1984 Figure 1b right Circa 2000 Xpander from the HP ACO group never released conf
14. commonly used in computer science An odd number has parity 1 The numbers 5 17 and 153 have the same parity 1 Numbers that are not odd are even Adding or subtracting two odd numbers will always result in an even number If a number integer may be divided evenly into two equal groups it is an even number Even numbers end with 0 2 4 6 or 8 An even number has parity 0 Adding subtracting or multiplying two even numbers will always result in an even number All combinations for adding subtracting or multiplying odd and even numbers are shown in Table two Table 2 Math Operations of Odd and Even Numbers Adding Even and Odd Subtracting Even and Odd Multiplying Even and Odd even even even even even even even x even even 2 6 8 6 2 4 6x2 12 8 3 11 6 3 3 2x5 10 7 3 10 9 3 6 3x7 21 HP Solve 19 Page 59 Page 3 of 11 Division of odd and even numbers that result in a fraction cannot be classified as odd or even because fractions are not odd or even numbers The terms odd number and even number are only used for whole numbers and their opposites additive inverses N4 Negative or Positive Numbers As we get older we learn to do arithmetic and typically by the 7 grade age 13 students learn about neg ative numbers One of the easiest ways to understand negative numbers 1s by visualizing a number line as shown below in figure five The line extends infinitely in both directions At the c
15. http www eecs berkeley edu wkahan abstrcts txt for a few of his papers Readers interested in calculator accuracy must read http www eecs berkeley edu wkahan MathSand pdf The HP15C is specifically mentioned and he consulted with HP on this machine Kahan was the primary ar chitect of IEEE 754 1985 standard of floating point computation He and his graduate students developed pro grams to run on most computers and many calculators to determine potential floating point bugs as avoidable and unavoidable Especially well know is paranoia Kahan is very vocal when computational accuracy is involved and he coined the phrase The Table Makers Dilemma The HP 71B is the only calculator to fully incorporate the standards of IEEE 754 About the Author Richard J Nelson has written hundreds of articles on the subject of HP s calcu lators His first article was in the first issue of HP 65 Notes in June 1974 He became an RPN enthusiast with his first HP Calculator the HP 35A he re ceived in the mail from HP on July 31 1972 He remembered the HP 35A in a recent article that included previously unpublished information on this calcul ator See http holyjoe net hhc2007 Remembering 20The 20HP35A pdf He has also had an article published on HP s website on HP Calculator Firsts aN See http h2033 1 www2 hp com Hpsub cache 392617 0 0 225 121 html HP Solve 19 Page 67 Page 11 of 11 HP Interactive learning for the 21st Centur
16. including serving as Peripheral Routines coordinator for the wA PPC ROM project for the HP41 in 1980 Currently working at Lockheed Martin 4 asa software engineer Jake has been presenting at and videotaping the annual U S HP calculator conferences for more than two decades lak HP Solve 19 Page 46 Page 5 of 5 HP Solve Math Problem Challenge 2 Article 1 in the HP Solve Math Problem Challenge series Cutting A Circle In Three Equal Pieces Solution Introduction In our last HP Solve issue 18 Marty had a problem of cutting a circle into three equal area pieces by making two parallel cuts The easiest way to make the cut is to measure from the circle along the diameter knowing the length h as shown in figure one The challenge as given 10 the problem was to calculate the ratio of h to the diameter h D Converting this ratio to a percentage would make cutting any sized circle into three equal pieces a simple task 11 the diameter 16 known or can be measured Two HP Solve readers responded with solutions Robert Orban and Pete Burns Robert solved the problem using Derive and Pete solved it using a more direct means rather than a software program While the latter is what was desired both HP Solve readers used document software that made it difficult to incorporate into Word 2003 which the editor uses Normally we am able to process inputs 10 various formats but as usual time was limited so we were not able to inclu
17. shown at right since this is anew program Then press the keys needed to access the function in the menu 8 m e These key presses will access the inverse cosine function in the Math Menu r This key press enters a STOP command This command ends program execution and returns control to the user To exit program edit mode press ggg 234 This returns the HP 30b to the program catalog and now displays Prgm 2 The number of bytes used by Prgm 2 16 shown below it 10 the display The program HP Solve 19 Page 7 Page 4 of 7 uses 7 bytes of memory and has a checksum of 219 To assign this program to the m key position enter the program catalog by pressing gag Press to view step 0 of this program where the key assignment will be entered To assign this program to the key position press g t The display should show SH8 where SH8 stands for shift hold 8 which is the shift hold cosine function position This inverse cosine assignment program will now work the same way the inverse sine program does Example 3 To assign the inverse tangent function to the shift hold 9 key position make a list of the exact keys pressed to access the function manually To perform an inverse tangent you would press 0 eur ee The final ur a final works just as well is necessary to have the HP 30b execute the function instead of just previewing the potential answer This is the same as the inverse cos
18. successfully tested we can snap the bottom shell in place This requires nothing more then lining the two shells up and starting at the battery housing Place the calculator on a solid flat surface over a towel with the keyboard facing up Press down firmly on the top above the metal keyboard overlay The yellow highlights in Figure 31 show the correct areas for pressing the shells together There should be a healthy snap as both halves of the four heat stakes in the battery compartment engage While on the flat surface work your way down the side of the calculator pressing on the plastic edge surround and feel it engage its clips When you have the battery and edges in place and while the calculator is still on a firm surface find a pen or drill bit with a flat surface at one end larger then the diameter of the heat stakes A 1 4 inch drill bit works perfectly here Place the flat end on a heat stake and press until it snaps together Work you way across until all four heat stakes are engaged The two shells are now together Do another systems test and this time listen for the beep of the piezoelectric transducer as it 1s now part of the system Fig 31 pressing points for At this point retrieve the now warped but separate keyboard overlay attaching the top shell to the Apply adhesive remover not solvent I use a citric based remover that lower shell HP Solve 19 Page 33 Page 11 of 13 does not interfere with the silk screened w
19. the weight 3 Cut off one 36 8 segment and weigh it Within the errors of the scale and the uniformity of the material the cut piece should be one third of the weight of the full circle HP Solve 19 Page 51 Page 4 of 8 Electronic scales that measure to 0 1 gram a new US nickel weighs 5 000 grams are low cost and becoming more available to the average student If you have access to an electronic laboratory scale that is sensitive to 0 1 milligram you will be able to achieve greater 1 000 times accuracy Let s confirm the result experimentally A small piece of 26 Ga sheet metal was used to cut a circle 18 cm 7 09 10 diameter The recorded data is shown in table two The circle was cut based on the solution described above and the pieces were weighed See figures two and three As the data of table two shows the error was within 0 9 percent A complete error analysis of this test Fig 2 Whole circle on scale Fig 3 1 3 circle on scale would include such factors as sheet metal variations very small cutting variations a little more significant and measuring variations significant skill and tool dependent Note Table Two entry 9 The cut length Chord is about 171 mm If the width of the cut varies by 25 2 mm7 171 0 15 mm 5 9 mils 0 0059 in the scale wouldn t detect it because of the 0 1 gr resolution With these considerations in mind what would have been a better circle size
20. to use The scale has a capacity of 250 gr The circle could have been larger and or thicker but still cut able to just be within the maximum of the scale capacity The resolution of 0 1 gr in 250 gr 1s 0 0004 or 0 04 vs 0 1 gr in 99 5 gr or 0 10 At least the larger size would provide a greater resolution in the weight ratio The actual accuracy of the scale isn t important just its linearity Scale linearity adds another factor to consider in an error analysis What other methods or materials would provide a more accurate measurement Table 2 Sheet Metal Circle Cutting Experiment 1 Circle material galvanized sheet metal Circle Diameter Circle area 0 53 mm 0 021 thick 18 cm 7 09 in 254 5 cm 25 450 mm O 1 ND NA BI W N e Distance to cut using 36 8 Circle weight to nearest 0 1 gr 1 3 circle cut piece weight Test piece 26 0 mm x 27 1 mm weight Scale resolution 6 62 cm 2 61 10 99 5 gr 3 51 oz 32 9 gr 1 16 oz 33 2 vs 32 9 is 0 9 2 8 gr for 704 6 mm area Cut weight difference of 1 3 weight 25 16 mm per 0 1 gr Table 3 Sheet Metal Circle Cutting Experiment 2 Circle material galvanized sheet metal Circle Diameter Circle area 0 38 mm 0 015 thick 29 1 cm 11 46 in 2 660 cm 266 000 mm O 9 NIT DN A AJU N e Distance to cut using 36 8 Circle weight to nearest 0 1 gr 1 3 circle weight to nearest 0 1 gr
21. whole numbers can HP Solve 19 Page 61 Page 5 of 11 also be negative so that would make them exactly the same as integers Sometimes people say that zero is NOT a whole number How strict you are will depend on your college major e g mathematics or en gineering Calculator convenience is often balanced with consistency It is the nature of people to avoid being bor ing by adding variety which often leads to being inconsistent While this quality has no place in mathe matics science or engineering people are involved and they will naturally be inconsistent regardless of their training or education Table three provides examples of the various kinds of basic numbers Table 3 Numbers Number Type Whole Numbers 0 1 2 3 4 5 Counting Numbers 1 2 3 4 5 Integers 5 4 3 2 1 0 1 2 3 4 5 Negative Integers wy 5 4 3 2 1 Non Negative Integers 0 1 2 3 4 5 N8 Formatting and Expressing Numbers Calculator numbers are floating point or optionally on high end graphing models integer A few models have a special fraction mode Floating point numbers include a fixed number of decimal digits displayed usually 8 10 or 12 digits The separator used between the integer part and the decimal part is called the radix In the US and many other countries the radix is a period Many European countries use a comma radix When very large long numbers are involved there are two common meth
22. with two holes punched in them at the top corners Or the label would have been deformed as it was peeled back exposing the screws Figure 4 Well that was when it was under warranty and since this is over 34 years _ old the warranty is well past Gaining access to the screws however does not have to ruin the label The following steps can be used to remove the label and restore it to its pristine condition for reapplication at the end of the repair 1 Carefully insert a sharp pen knife under the corners of the label 2 Luft the corners as indicated in Figure 4 exposing the two middle screws i Carefully insert a sharp pen knife under the corners of the label Fig 4 Hidden warranty screws Carefully insert a sharp pen knife under the corners of the label Lift the corners as indicated in Figure 4 exposing the two middle screws Pry off the two rectangles at the top of the calculator exposing the top screw Lift the outer edge of the two lower rubber feet These feet are pinned on the inner half to the calculator so don t try to remove them Just lift enough with a pen knife to expose the two lower screws DAMA HP Solve 19 Page 25 Page 3 of 13 8 Remove all six screws Once separated from the top shell the label can be heated by a hair dryer As the label heats the adhesive softens and the label can be pulled off Using a cycle of heating and pulling remove the label Try not to crimp the label but don t
23. worry as all the creases will be removed To smooth the label for use after the calculator is fixed follow the next seven steps 1 Heat the label 2 Remove the label 3 Remove the adhesive from the label citric based adhesive remover will work 4 Remove the adhesive from the bottom shell 5 Place the label between two thick sheets of vinyl an ID holder works well Figure 5 6 Place the ID holder and label facing up on a flat surface a thick glass pane on a kitchen counter for example 7 Heat the label Fig 5 Example of label in vinyl ID holder 8 Remove the label 9 Remove the adhesive from the label citric based adhesive remover will work 10 Remove the adhesive from the bottom shell 11 Place the label between two thick sheets of vinyl an ID holder works well Figure 5 12 Place the ID holder and label facing up on a flat surface a thick glass pane on a kitchen counter for example 13 Using the bowl of a spoon rub the ID holder containing the label 14 Flip the ID holder over and rub the back side of the label This has the effect of cupping the label which aids in its reapplication 10 the future The internal components of the calculator including the card reader are exposed in the top shell Referring to Figure 6 the following components are labeled as well as the location of six more screws indicated by yellow dots A Card reader motor B Battery contacts and polarity C Logic PCB assembly
24. 10 9 8 7 6 5 4 3 2 1 01234567 g 9 10 C 1 2 3 4 5 Subtract 5 trom 3 d 10 9 8 7 6 5 4 3 2 1 0 1 7 34567 46 910 Fig 8 Subtracting examples See table three HP Solve 19 Page 60 Page 4 of 11 Negative numbers may seem confusing especially if a larger negative number is subtracted from a small er positive number See figure eight of the four possibilities of positive and negative numbers Zero 1s neither positive nor negative Adding and subtracting positive and negative numbers may be summarized as shown in table three Table 3 Adding And SDA And Negative Numbers 3 b variables a amp b Adding Add Result amci Result o ha 06 O A ab ss 2 35 _ C 3 Poell a OT 3 65 The sign rule is Subtracting a negative number two negatives e g 3 5 is the same as adding N5 Integer or Decimal Numbers Integer numbers are natural numbers defined in a strict rigorous mathematical sense is beyond the level of this fundamental review include the whole numbers both positive and negative The definition of an integer is consistent with usage so when in doubt say integer and if you only want to include positive integers say positive integers This is more accurate and being specific makes you sound intelligent Zero is normally neither positive nor negative Two numbers that form a fraction with a normal remainder e g 1 4 may be represented as a decimal 0 25
25. ER keys are identified in figure three below 15C 29C 27 35A 34C 39S 425 41CX 48GX 55 50g 65 70 67 97 19C Fig 3 Enter key models identified thanks to Jake Schwartz RPN Tip 19 RPN vs RPL The first HP machine to challenge the logic system superiority of RPN was the HP28C announced June 1 HP Solve 19 Page 15 Page 4 of 10 1986 with its introduction of RPL A Wikipedia article on RPL states According to a quote by Dr William Wickes one of the original RPL developers the development team never calls it anything but the initials RPL See note 1 It is not the intent of this RPN Tip to describe and explain RPL but rather to contrast RPL with RPN The important idea the reader should come away with is that RPL and RPN are very similar and yet different These two logic systems are similar in that RPL may be thought of as a more pure RPN RPN Tip 4 explained the basic calculator operating systems noting that RPN uses postfix logic The basis for postscript and RPN is that the operator always follows the data The most important user concept to remember is that no calculator is pure anything Every HP calculator model is a unique compromise of functions features applications and its operating logic system The obvious example that makes RPL more of a pure RPN is the store and recall register instructions With legacy RPN these instructions operate when the key is pressed and then the use
26. HEWLETT Ki PA CKA H 5 LN XEQ Fig 33 Yellow highlights on HP42S Fig 34 Upgraded memory HP42S Fig 35 non upgraded memory indicate suggested glue pattern for with SIZE 025 and new keyboard flex HP42S with SIZE 025 and new reassembly PCB pressure pad keyboard flex PCB pressure pad When you are satisfied with the results it is time to glue it in place remember the overlay is 90 of the look of the calculator Using contact cement and the end of a toothpick or some other fine pointed instrument apply glue to the keyboard 10 a manner suggested in Figure 33 Apply corresponding drops of HP Solve 19 Page 34 Page 12 of 13 glue to the keyboard overlay These should be thin applications Following the directions on the tube allow the glue to dry and become slightly tacky to the touch prior to applying the overlay Line up the bottom edge of the overlay onto the bottom edge of the keyboard Get this right the first time otherwise you will have to repeat the entire overlay cleaning and straightening exercise Once in place apply pressure to the four corners the top edge and the bottom edge and sides to ensure a good contact If you ever have to enter the calculator again this technique allows you to open the calculator using a fine knife without ever having to remove the overlay again In effect you will have a snap together HP42S just waiting for memory upgrade Speaking of which here is the finished product with a new foam overl
27. HP Solve Assigning Menu Functions on the HP 30b Keyboard Gene Wright Read and see how to program the HP 30b to bring deep menu functions to the keyboard Your articles Regular Columns From the Ww ww Editor As HP Solve grows the current structure will adapt as well Learn more about the current changes goals and feedback from the latest Solve newsletter Today s HP 41 User Peter Platzer After reading about the 30th anniversary of the HP 41 in HP Solve Issue 16 Mr Platzer shares his personal experience with this classic 3603 HP calculator HP Solve Math Problem Challenge 2 Learn the solution to the first math problem challenge from Calculator Restorations Ww w Ww w Geoff Quickfall How do you keep your calculators functioning Check out a sneak preview of Mr Quickfall s future book A Guide for the restoration of Hewlett Packard calculators E Ink Haptic Touch and MEMS Jake Schwartz The HP 35A helped spark wish lists and dreams among users for future calculator ideas In this issue Jake examines three emerging technology ideas as they address historical calculator issues Fundamentals of Applied Math Series 2 Richard J Nelson This new series looks to Issue 19 June 2010 Welcome to the nineteenth edition of the HP Solve newsletter Learn calculation concepts get advic
28. I was able to realize that dream spending a summer s worth of earnings on a used 41CV which 2 eventually was completed with a card reader and X F Fig 1 Nelson F Crowle was one of the earliest module By then the PPC module had been out for a pioneers of MCODE development on the HP 41 couple of years the CCD module was old news and first and the developer of one of the first sightings of the 41CY and MLDL s were reported commercially available MLDLs The above Again not being able to afford the necessary equipment Pictured ProtoROM and ProtoCoder each offers aka gadgets true HP 41 development and discovery was 4k of user programmable RAM and 4k of ROM if a spectator sport for me used in combination with the ProtoEPROM PROTOEPROM E Fast forward 20 years One day at work I needed a calculator to tackle the odd little calculation for which you don t want to fire up Excel or Matlab Remembering the HP 41 and all the nostalgic longing it embodies for me I thought Maybe I can pick one up on eBay for cheap for memories sake Boy was I in for a surprise That purchase opened the door for me to a vibrant brilliant and exceptionally helpful community of HP Calculator enthusiasts Today 30 years after its introduction the HP 41 is as revered used and talked about as ever I was not alone with my dream not by a long shot In the ensuing years I learned a lot of math by solving Short And Sweet Math Challenges
29. P cakculstors Ap Buy online or Call 800 BUY MYHP Products amp Services Support amp Drivers HP Calculators Find a financial calculator graphing calculator or scientific calculator for work school or home Home amp Home Office HP 10bll 12c 12c Platinum 17bil 20b Business HP 10s SmartCalc 300s 33s 35s 3995 4095 Laptops amp Mini Netbooks Consultant Desktop amp All in one PCs Printers amp All in ones Ink Toner amp Paper Monitors Accessories amp Software Scanners Handhelds Calculators Storage Home Servers Services All Consumer Products Photo Printing Services E Mail Sign Up For Hot Deals Financial calculators for home Financial calculators for business amp school Graphing amp scientific calculators for home school e Financial Calculators ideal for business finance real estate banking and accounting Small amp Medium Business HP calculaters are proven trusted and accurate and surveying Step 2 Click on the link that says Click here to sign up Contact HP Calculator Newsletter Small amp Medium Business HP SOLVE Browse amp Buy Products HP Calculators Deals amp Offers Services amp Total Care SIGN UP NOW Graphing amp scientific calculators for business amp e Calculators ideal for math science engineering CALCULATING SOLUTIONS POWERED BY
30. Test piece 26 0 mm x 27 1 mm weight Scale resolution HP Solve 19 Page 52 10 7 cm 4 21 in 194 7 gr 6 87 02 65 7 gr 2 32 02 64 9 vs 65 7 is 1 2 2 1 gr for 704 6 mm area Cut weight difference of 1 3 weight 33 55 mm per 0 1 gr Page 5 of 8 A second measurement experiment 2 was made using a 25 thinner but larger piece of similar galvanized sheet metal which was available See recorded data in Table 3 Note that the error is in the second experiment and in the first experiment compared to theory Do any Questions Remain The problem has been solved but it required a calculator solver to arrive at the answer Are you convinced that the 36 8 solution is correct Are there other solution methods Is it possible to solve the problem using a direct trigonometry solution without iterating trial and error as done by the solver Is there an exact solution Share your comments on these questions via the editor with the readers of HP Solve hpsolve hp com Math Challenge 1 Notes 1 The equations you find will vary greatly depending on the reference you use The Table 7 equations were used because they provided one obvious path for a solution Would other equations provide an even simpler solution 2 US coins are useful to use as informal and readily available standards Go to any bank and get a roll of uncirculated coins nickels Since the nickel does not have reeds it ma
31. They donated over 300 000 towards the project and 5 200 Custom ROMs were made by HP A 500 page User s Manual 30 000 copies printed was written by users for users as an example of the kind of applications information they thought was important The project itself was unusual because it involved so many people in many different countries donating in excess of 876 581 hours of work one man century without compensation of any kind This was before the Internet The project is an example of what is often called open source software and was recently mentioned in an embedded Systems blog Qt http www embeddedcomponents com blogs 2007 04 community software development for embedded devices CCD module an amp k extension module with 100 new functions was created by the Computer Club Deutschland and produced by W amp W Software Gmbh It was a true extension of the Operating System of the HP 41 and allowed manipulation of the system registers with unsurpassed ease powerful matrix and binary functions and many other advanced functions that made working with the HP 41 an even greater delight MLDL Machine Language Development Laboratory is an external device to the HP 41 that allows programming the HP 41 in its native Assembler language of the NUT CPU MCODE see below It allows the creation of individual system extensions as well as up to 32k RAM storage in its first versions about 14x the stock RAM of the HP 41CV Later versions provided up to 128
32. air components was developed to aid in repairs After all you would not expect to throw out your new laptop because a RAM chip died This paradigm ensures the early versions of HP calculators are easy to access for repair As time passed a choice was made to make the calculators disposable The cost of memory decreased and the size of components shrunk production was more automated and the life expectancy of the materials increased Hence the physical construction veered from removable screws to permanent heat stakes Concomitantly the cost of repair of individual components outweighed the benefit of purchasing or replacing the unit This is fine as long as there are replacements for your calculator out there What do you do if your prized calculator 1s discontinued Collector or User Let s say you are a collector that would like to own and use a functioning HP 65 with its gorgeous LED display and programmability Their continued use still happens I for example have been known to pack my HP 65 10 my flight bag The looks I get when I pull it out and it performs a function for the flight is always one of appreciation or downright awe especially when the card reader is used for program loading Conversely as a user my day to day calculator for work 1s an HP42S which I have upgraded from 7K to 32K and have also repaired due to a bad keyboard PCB to logic PCB connection more on that later Fortunately for you the collector or user there are
33. alue Ask any multilingual person to do a simple number problem or do something related to counting Next ask this test subject what language he or she used for the numbers The odds are very high that it will by the subject s native first learned language e g the speaker uses English but counts in German N1 Cardinal and Ordinal Numbers Cardinal numbers are the numbers we have been talking about They are the regular or normal numbers we use for counting If however we wish to indicate the position of a set of numbers we may use ordinal numbers such as the first third fifth six hundredth etc These terms have strict definitions in Number theory and these aspects are best studied from a Number Theory reference N2 Counting Numbers Counting Numbers are Whole Numbers but without the zero Because you can t count zero Computer and some calculator related systems do count starting from zero This is done for convenient electronic implementation reasons The first memory location of a program or series of registers is one not zero Using zero as the first register 1s justified to maximize the number of registers with a single digit key designation keystroke See N7 below N3 Odd or Even Numbers If a number integer cannot be divided evenly into two equal groups it is an odd number The remain der will be 1 Odd numbers end with 1 3 5 7 or 9 The oddness an attribute of a number is called its parity which is most
34. am singer at Carnegie Hall and hiker in the hills of the east coast he passionately programs repairs and collects HP calculators Email me at pplatzer hbs edu HP Solve 19 Page 40 Page 4 of 4 E Ink Haptic Touch and MEMS Article E Ink Haptic Touch and MEMS Jake Schwartz Ed note When it comes to calculator ideas there is an endless supply Users have had wish lists and blue sky dreams for the future since the HP 35A Jake however examines three emerging technology ideas as they address historical calculator issues There should not be any implication here that HP is considering these technologies Consider yourself on a typical day with a collection of HP calculators whereby you can reach for and use any one depending upon the particular need at the moment For balancing the check book you might pick up an HP32SII or 11C for computing the interest payments on your next car loan you might grab the HP17bII and for converting kilometres per liter to miles per gallon or perhaps plotting a function curve the 50g Now how about if by magic all these machines could share the same stack and memory registers so a problem started on one could be continued and completed on another without skipping a beat What would be simulated here would be a universal HP calculator with multiple personalities each with a real tactile keyboard and keys 10 all the familiar places and actual authentic display A not quite fulfilling attempt
35. angle by pressing 2 5 s The display should appear as shown below a ute To find the angle again by executing the inverse sine function press f 7 The display should appear as shown below Note that in this example an assignment was made to a key position that already had a shift hold function assigned to it by the HP 30b itself the CALL programming environment function In the calculation environment the inverse sine program assignment will be executed If you press this shift hold key position while editing a program the CALL function will be entered into the program since that assignment is active 10 program mode Example 2 To assign the inverse cosine function to the shift hold 8 key position make a list of the exact keys pressed to access the function manually To perform an inverse cosine you would press Gm Mors eur C ner The final a final works just as well is necessary to have the HP 30b execute the function instead of just previewing the potential answer This is the same as the inverse sine program listing except for one additional key press e Enters program mode and displays the last program previously viewed in the program catalog Place the inverse cosine program into Prgm 2 You may need to press a few times to move the program catalog location until Prgm 2 is displayed Then press Enters program edit mode and displays the first line of the program which will be blank as
36. ard PCB to the Logic PCB We will fabricate a replacement and then reassemble the calculator These two examples represent each end of the spectrum with relation to the repair design philosophy mentioned earlier The HP 65 was made to be repaired its initial cost was 700 USd which is the equivalent of approximately 2100 USd today It made sense to repair it The HP42S however is held together by heat stakes and contact adhesive The stakes were a permanent bond and the calculator shell was most likely opened and sacrificed under the warranty Outside the warranty 1t was cheaper to purchase a new one Of course they no longer are made and tech support is non existent now A used one goes for 100 to 200 USd depending on the demand at auction sites The problem with purchasing a used replacement is it will if it does not already suffer from faulty foam pressure contact material as well as any other abuse that it may have suffered from the previous owner The HP 65 Classic Figure 1 Faulty HP 65 Figure 2 Completed calculator Figure 3 Screw locations HP Solve 19 Page 24 Page 2 of 13 This calculator represents the early days of programmable calculator design It was the first with a card reader hours minutes seconds HMS conversion to decimal hours HR and base conversions It also has the distinction of accompanying the astronauts on the Apollo Soyuz mission where it performed mission critical computations The reason for the card read
37. ay and the memory upgrade Figure 34 Compare the display with that of an original HP42S with only the foam upgraded Figure 35 Closing Notes 1 The historical information used in this article may be found in A Guide to HP Handheld Calculator and Computers W A C Mier Jedrzejowicz PHD 2 The label smoothing method referred to in the HP 65 and HP42S sections 16 similar to one Mark Hoskins described in 2002 at the Museum of HP Calculator Dave Hicks curator 3 The keyboard diagnostics for the HP42S may be found 10 its manual 4 The keyboard overlay removal method mentioned in the HP42s was described to me by the creator of the method Tony Duell HPCC librarian member and hacker in residence 5 Inthe section HP42S if you drilled too much off the heat stakes resulting 10 a loose fit place a small drop of liquid plastic model cement on the exposed heat stake surface while applying pressure for the correct amount of time as per the instructions Conclusion I hope you found the above instructions helpful and maybe they will get you into the repair mind set The book itself will be approximately 200 pages with about 200 illustrations similar to the figures in this article In fact most of these figures are from the book I am a great fan of illustrations as they make the text much more understandable Like a cookbook with the end product of your labour displayed in full colour About the Author Geoff Quickfall is an HP calculator
38. board ribbon A Figure 27 Once you are satisfied with your new foam insert and the resulting height of the keyboard flex PCB it is time for reassembly If you are upgrading the memory now 18 a good time of course you will need the book for that modification All contacts should be cleaned and free of contaminants Figures 28 and 29 Use contact cleaner on a AAAA amp cotton rag such as an old bed sheet and blow any remaining Fig 27 relative 0 comparison of dust from the contacts Place the logic PCB keyboard ribbon to tab HP Solve 19 Page 32 Page 10 of 13 in place over the straightened tabs Press firmly at each tab area and bend the tabs back in place Use the same direction used by the factory Ensure that there 1s a good contact at each tab Figure 30 At this point replace the batteries and test the functions as per the manual Fig 28 Clean highlighted areas Fig 29 Clean highlighted areas Fig 30 Logic PCB in place The only function that should not work although the calculator self test does not register a fault will be the piezo transducer as it is attached to the bottom shell If successful it is time to close the calculator If not successful then check the tabs are bent correctly as they were initially The tabs are responsible for holding the logic PCB in position firmly over the keyboard flex PCB and the foam pressure pad Check for dirt on the contacts and retry Now that the logic PCB is in place and
39. brief history of HP calculator displays was provided to illustrate the various considerations for the best display number The numbers in Table One were keystroke digit evaluated with the golden ratio p Suggested as one of the most interesting numbers In terms of the guidelines provided however the golden ratio required a few too many keystrokes espe cially if you are photographing multiple machines in the same photo because of auto turn off ACE 1 FD J Numbers as a topic of popular interest is interesting enough to merit its own Fig 1 HP35s as U S prime time TV series Numb3rs 2005 7 keyboard is typical Table 1 Suggested Photographic Display Numbers T 3 14159 26535 89792 e 2 71828 18284 59045 2 1 41421 35672 373095 13 1 73205 08075 68877 Tan 7 0 12278 45609 02906 p 1 61803 39887 49894 Every number has its own personality and Wikipedia accepts number N N number as an input The reader can explore his or her own favorite numbers to discover the personality of the numbers discussed thus far on Wikipedia An example including linked references 11 you want to explore advanced number concepts further for the Lucky Number 7 is copied in shadow box 1 on the next page from Wikipedia The mathematical details in Shadow Box 1 are only one aspect of the in depth information of the numbers that are included on Wikipedia Shadow box 2 on page three sh
40. cgi read 147587 Third it connects me with a worldwide community of like minded people many of whom I knew for years 10 the cyberworld before meeting them face to face in one of the annual or bi annual conferences held in the US and Europe And then there is always the excitement of the hunt for that one elusive device for my collection that is particularly hard to find 64k W amp W Rambox anyone Ptr gt Micsclisle foo SS NSS Br ed SSS See gt oe teti eae HEPA ADVANCED HEPAX MODULES 1116 f _ a a z a 0 for HP 41 4 22222 a a eS aes f f i Fig 5 A very early MLDL probably designed by Lynn Fig 6 Photograph of the Advanced Hepax Wilkins providing 4k of user programmable RAM And this is mentioned in the article and explained in note 5 already version 2 with the earliest versions being mostly wire This is a good example of the many third party wrapped concoctions products produced for the HP 41 system The HP 41 is a great example of the powerful benefits individual users can get from being part of a large network It was sold over 1m times creating a powerful network effect for its users Whatever your particular problem chances are that one other user has had the same problem and has come up with a solution This is still true today Case in point is one of the most recent modules for the HP 41 written HP S
41. ct information please visit our privacy statement or write to us at Privacy Mailbox 11445 Compaq Center Drive W Houston Texas 77070 ATTN HP Privacy Mailbox Hewlett Packard website Sign up for Driver and Support Alerts Assigning Menu Functions on the HP 30b Keyboard Article Assigning Menu Functions on the HP 30b Keyboard Gene Wright Ed Note The HP30b is extremely fast and while its memory seems limited its speed makes up for it in many ways Gene recently demonstrated its speed at HHC 2009 with a prime factoring bench mark program Having the many added scientific math functions on a finance machine is made even more convenient by assigning these functions to the key of your choice Gene provides the step by step instructions for doing this The HP 30b Business Professional calculator includes a programming capability designed to help automate repetitive calculations and extend the usefulness of the built in function set of the calculator The capability includes the creation of up to 10 separate programs using up to 290 bytes of memory among them Programs record keystrokes with each keystroke using one byte of memory although some commands use more than one byte In addition many program only functions are provided for conditional tests gotos looping displaying intermediate results and even calling other programs as subroutines This article will show how to bring functions out of menus and assign
42. d position Begins by showing an A in the display Press the following keys to enter the message INV SIN p Moves character position to display an e Enters the I character and presents a lowercase a after pressing the key Moves character position to show N Enters the N character Moves character position to show V Enters the V character Moves character position to a space which is present but not visible in the image at right Enters the space character into the string Moves character position to S Enters the S character into the string Moves character position to I ai Enters the character into the string Moves character position to N Page 6 of 7 Press to terminate entering the message The display will shift to show line 2 of the program Now view the program once again in the program catalog by pressing ama E INPUT BaD INS Although this takes some key presses to input some users will find this ability to give a title to a program very useful as the function of the program will be much more evident from INV SIN being displayed in the program catalog than the generic Prgm 1 The title is displayed in reverse video because this program is assigned to a key from example 2 Note that inserting the MSG to give this program a title used an additional 9 bytes of memory 15 6 for the original p
43. de their inputs here Kudos to you both The winner however is Wolf Dieter Schone of Cochem Germany His solution arrived just as the issue was being assembled Excellent work Wolf Here is his solution Solution of HP Solve Math Problem Challenge 1 Wolf Dieter Schone In order to solve the problem the following figure is helpful The points A D and E correspond to the same points in the figure of the newsletter M denotes the center of the circle So d corresponds to the distance AG of the figure in the newsletter and A to half of the length of GH s is the segment DE and the basis of the triangle MED A is the height of this triangle A its area According to the figure there are seven unkowns the angles and the areas A which should be one third of the area of the full circle A the section corresponding to 2 and A and furthermore A and s The radius r is given These unknowns are connected by seven equations HP Solve 19 Page 48 Page 1 of 8 IT a I ee 0 p 2 2 I 722 2 00 a 21 2 000 4 4 4 V 4 2 4p gt V cos sin B VI h r VII A Inserting I in II the new ID in IV and rewriting II gives JT aA I Sa I r II A a A r a III A r 1 r a 1 IV A r a A A oe z Z 4 9 V cos 5 z sin 8 5 2 VI M ear 1 VID eae Solving IV for A and equating with VII lead
44. different tasks all without any increase in form factor 7 W amp W Software http wwsoftware de homepage en html was founded in 1984 in Germany by members of the CCD club to focus on MCODE development for the HP 41 with the CCD module being its first product Its most famous product from that period is probably the HP 41CY an HP 41CX with an internal 64k memory expansion as well as a turbo switch that made the CY run twice as fast as a stock CX 8 Angel Martin created among other modules the famous HP 41Z that gives the HP 41 full complex math capabilities and the Sandmath module that provides 128 advanced math functions all written in MCODE Generous with his hard work he publishes all his code including the source code under a GNU license http www hp41 org LibView cfm Command Author amp AuthorID 2974 9 A collaboration between Angel Martin and the author it can be found here http www hp41 org LibView cfm Command View amp ItemID 905 About the Author Peter Platzer was born in Vienna Austria where he studied Physics at the TU Wien After a short and breadless stint as a scientist he joined capitalism first somewhat tentatively as a consultant for the Boston Consulting Group in Germany and Asia Later while at Harvard Business School Wall Street s siren song lured him to New York City where he 1s still searching for the wonders promised In his free time a career coach captain of a Volleyball te
45. e A fixed two mode shows dollars and cents The 35M example in fixed two mode displays as 35 000 000 00 If the display was Set to fix 5 it would show 35 000 000 0000 in a 12 digit display because the display limits the number of decimal digits shown Divide the number by 10 and the display shows 3 500 000 00000 Divide again by 100 to show 35 000 00000 HP Solve 19 Page 62 Page 6 of 11 Scientific mode shows the number as a multiplier of a power of ten 1 000 is shown as 1 x 10 Most cal culators use E in the display for the 10 The 35 million example in SCI 1 would be displayed as 3 5E7 Multiply by 10 to see 3 5E8 Change to SCI 2 mode to see 3 50E8 Engineering Mode displays the number similar to Scientific mode in such a way that the exponent is al ways a multiple of three The 35 million example in ENG 1 would be displayed as 35E6 Multiply by 10 to see 350E6 Multiply by 10 again to see 3 5E9 The 3 5 part is called the mantissa and the E part is called the exponent These values may be positive or negative Note how the mantissa is changed until the exponent reaches a multiple of three and then the mantissa will show the number of digits based on the number entered when the Engineering mode was set ALL Mode displays all that it can with commas Our 35 million example is dis played as 35 000 000 without a decimal point If the number of digits is too high it reverts to displaying in scientific mode There is also
46. e 2 of 10 RPN TIPS RPN Tip 19 RPN vs RPL In HP Solve issue 18 the ENTER key was discussed and the article closed asking the following questions Q BTW why was the first production ENTER key blue and why was it changed to blue when the prototype was shown to Bill Hewlett What color was the first HP 35A ENTER key prototype shown to Bill Hewlett A The HP 35A design team used yellow for the ENTER key and white for the case When they showed a prototype to Bill Hewlett he reminded them that the HP corporate color was blue It was immediately changed to blue All but one member of the design team changed his machine to use the blue keys That machine was donated back to HP at the IEEE HP 35A presentation at HP Labs in May of last year See HP Solve issue 13 and RPN Tip 14 in issue 14 for more details of this event The HP35A was photographed at that time and is shown below This is a rare machine indeed Fig 1 A rare prototype of the HP 35A that used different colors HP Solve 19 Page 14 Page 3 of 10 The second question that was asked in RPN Tip 18 is answered below Q Now that you are thinking about the ENTER key here is a challenge for the serious HP calculator fan suggested by Jake Schwartz What models used these enter keys Send the editor your guesses ENTER ENTER ENTER ENTER ENTER 4 ENTER Fig 2 Enter key variations used by HP calculators A The ENT
47. e Internet HP Solve 19 Page 16 Page 5 of 10 This similar yet different aspect of RPL is confusing and challenging for legacy RPN users Bill Wickes recognized this while developing RPL and by the time the 48 machines arrived he decided that a book was needed to explain the differences 10 RPN terms and HP gave him permission to market the book See figure four above A comparison of RPN and RPL stack operations is made in two tables 10 the book See figures five and six below Another contrast RPN makes with RPL is that all HP RPN calculators use a four high stack and all HP RPL calculators use a memory limited open ended stack Placing a thousand objects on the stack is common practice for RPL users Table 2 2 HP 41 and HP 48 Stack Commands Table 2 1 HP 48 Stack Manipulations HP 41 Command Pu eares rpose Nearest HP 48 Equivalent ia eiia Remove last entry DROP SAEF 5 DROP Discard the level 1 object DROP2 Discard the objects in levels 1 and 2 DROPN Discard the first n objects CLEAR Discard all stack objects Clear the stack CLEAR Enter four 0 s 0 DUP DUP Exchange X and Y SWAP Roll up four levels ROLL A gt Rall op the catie stack DEPTH ROLL SWAP Exchange the objects in levels 1 and 2 ROT Rotate the level 3 object to level 1 ROLL Rotate the level n object to level 1 ROLLD Rotate the level 1 object to level n Roll four levels down 4 ROLLD Roll down the entire stack DEPTH ROLLD Terminate digit entry or any deli
48. e Pocket PC PDAs No Tactile Feedback One of the problems with all these touchscreen solutions from Xpander to iPhone has been the lack of tactile feedback like a real HP calculator keyboard Recently a few companies have started offering haptic touchscreens on their products These usually cause the device to vibrate momentarily when touched giving the user a feeling of having positively pressed something on the flat surface However all the ones I have experienced have suffered with the same shortcoming which is that feedback 16 always provided no matter where the screen is touched Ifa key has actually been pressed I want feedback but by the same token if I press between the keys or anywhere else I need that keyboard to do nothing This represents the realistic way to know that the touch did not activate any key s It is felt that this difference would represent a significant advance toward simulating a real keyboard Electronic Ink and Keyboards Another upcoming technology in consumer electronics has been the use of electronic ink or E ink based displays Two major advantages of these are extremely high contrast along with persistence when powered off Both these attributes make E ink ideal for digital signage and examples of small digital signs using this technology were shown at a recent Consumer Electronics Show by the LG Company Another currently popular use for E ink is in handheld digital book readers such as the A
49. e for the Hewlett Packard calculators HP49G HP50G is directed to engineers technicians scientists teachers and students The great advantage of the HEUSON SOFTWARE all data can edited freely so as to never lose their values You may obtain the details at http www heuson software de HP Solve 19 Page 20 Page 9 of 10 HP 49 SERIES 4861 3 hpcale org http www hpcalc org is the premier source of software for and information about the HP 50 HP 49 HP 48 and HP a F T 28 RPN programmable graphic calculators and the HP 38G HP 39 and HP 40 programmable graphic calculators with 7078 files by 2136 authors and 2969 screenshots totaling 697 9MB You may also order the complete website on a CD or DVD Once the content exceed the CD it will be burned on to a DVD Fig 3 Primary machines supported 4 If you are a surveyor you should check out the D Zign website Ted Kerber has been offering low cost HP calculator survey software for many years If you are a surveyor and you use the HP33s ig 4 lowest cost survey programs HP35s or the HP50g you will want to checkout Ted s offerings Get the details at http www softwarebydzign com HP Solve 19 Page 21 Page 10 of 10 Calculator Restorations Article Calculator Restorations Geoff Quickfall Ed Note HP Solve interviewed Geoff in Issue 12 Introduction Calculators have been around in one form or another for many y
50. e fourth digit is all that is considered You don t care what the fifth and additional digits are Rounding is different from rounding up or rounding down or truncating The rule taught 10 most elementary schools especially in the US however is what is often called the 5 4 rule You always round up if 5 and higher and you round down if 4 or lower This rule is followed by nearly every calculator made because it is simple Since HP Solve is read internationally I would love to hear from our non US readers what they learned 10 school How were you taught to break the tie of the middle five I learned a different rule I learned what I remember as the Astronomer s Rule of rounding If you have a 5 tie situation you round up if it makes the preceding digit even other wise you don t The idea is that statistically you spread the favoritism around statistically evenly If you want to delve into the subject of rounding you may find a very good article at http en wikipedia org wiki Rounding N10 Significant digits The idea of significant digits 1s to recognize that data and calculations result in a lot of digits in numbers that are not really significant It is like the links ina chain The chain is only as strong as the weakest link The number of digits 19 only as accurate as the smallest number of known accurate digits involved Suppose you have a number of measurements involving instruments of kno
51. e to help you succeed in the office or the classroom and be the first to find out about new HP calculating solutions and special offers Contact the editor HP in the Classroom HP Interactive learning for the 21st Century Classroom Learn how HP designed the affordable easy to use 39gs Graphing Calculator to enable math teachers to spend more time teaching and less time showing students how to use their calculators Learn more gt HP Solve Newsletter the last newsletter In addition explore and explain the math Having trouble here s another opportunity to that we use with our registering for the HP showcase your ability to solve calculators in terms of real Solve newsletter a new challenge world application and use Part lt only takes a few two of a three part series minutes to sign up and continues exploring Numbers it s free Learn how to register with these easy step by step instructions Learn how to register Product information eee eee SSS Update Profile Change Email Unsubscribe HP Home Support amp Drivers i If you received this e mail from an associate and or would like to receive email of this type directly from HP please click here HP respects your privacy If you d like to discontinue receiving these type of e mails from HP please click here For more information regarding HP s privacy policy or to obtain conta
52. e we will look at what is probably the main failure point on the Pioneer and Stretch Pioneers series the failure of the keyboard This problem manifests itself in many ways starting with the obvious The calculator won t turn on Other indications is once on the calculator won t turn off or a row or more of keys become unresponsive This is usually due to the fact that the keyboard is not communicating ae physically with the logic PCB The physical aspect of the O Pee communication relies on a foam pressure pad to maintain a pressure contact between the keyboard flex PCB and the surface of the logic PCB The failure of the foam is gradual and usually indicates itself by the need for increased pressure to execute a key function and continues until a row of keys are unresponsive If this involves the far left set of keys then the calculator may not turn on To confirm the foam pressure pad is the culprit simply press gently on the keyboard in the area indicated by the yellow strip in Figure 14 While pressing turn the calculator on and execute any of the faulty keys If they work you have confirmed the fault to be the foam pressure pad APN SOENTFIC Since the pressure pad 16 determined to be at fault it is time to open up the calculator What no screws As stated earlier this calculator was not meant to be opened by the user yet thanks to the intrepid community techniques have been derived to access the internal components The
53. ears but the arrival of the HP 35 in 1972 heralded a new era Here we are thirty eight years later and the demand from users and collectors for HP calculators is extremely high including the now 38 year old HP 35 The HP community which I divide into users and collectors big overlap on that bell curve have long been interested in preserving their favorite calculator either for sentimental reasons or for use as a preferred model Many questions have been posed about keeping calculators functioning which have exceeded their design life and are still desired by the owner Subscribers to the various forums dedicated to the HP calculator user are responsible for many innovative techniques developed to keep these marvels of design alive and well To that end I am creating a book titled A Guide for the restoration of Hewlett Packard calculators This book is directed at the collector and user and spans the families of HP calculators from the Classics circa 1972 to the Stretch Pioneers produced until 2003 inclusive Physical Design A major problem evolved during the evolution of the calculator I refer to it as the repair design Dhilosophy 10 the early days the reparability cost was considered with reference to the physical design both of the shell and the logic PCB The financial cost of a scientific programmable calculator like the HP 65 was equivalent to the purchase of a laptop computer of today Therefore an ability to easily access and rep
54. enter is zero The numbers to the left are called negative numbers The numbers to the right are called positive numbers Increasing positive values go to the right from zero Increasing negative values go to the left from zero From a value perspective a negative three is equal to but opposite of a positive three You may think about the result of comparing a positive and a negative number as two teams in a tug of war If both sides are equal there is no movement along the line If a positive team has a value of four and the negative team has a value of five the positive team are not able to with stand the extra value of one and the result is movement 10 the negative direction by one value We may visualize the addition of numbers by superimposing the values on the line Adding 2 and 3 for example extends the line value of 2 with the line value of 3 to get 5 as shown 10 figure six The evolution of our numerals 3 5 c 738 9 4 yP e679 Brahmi Indian Gwalior 2 3 IRJ ET SO Sanskrit Devanagari a a 5 G 7 Aaea 4 2 4 9 West Arabic Gobar Fig 7 Adding 5 to 2 has a value of 3 See text Subtract 5 from 3 f ee 012345678910 d 4321 Subtract 5 from 3 15th Century Anon Y 1 2 34 5 6 fT 686 9 12534567890 16th Century Diirer Subtract 5 from 3 1 2 3 4 5 Fig 4 Evolution of our numerals ee ee 012345678910
55. er was that memory was expensive limited in size and not continuous that is once the machine was turned off the program was lost Therefore the addition of a card reader to the calculator solved the problem of keying in programs each time the calculator was turned on Figure 1 illustrates the calculator requiring repair There were quite a few things wrong with this calculator some cosmetic and some electronic e A Crystal is scratched and gouged e B The OFF ON switch is intermittent in function e C Two keys do not register and 5 more bounce multiple registers per single push e D Case damage preventing access to the card reader e E The bezel is dented and chrome paint worn or missing The following also needed repair e Corrosion on the contacts of the keyboard PCB to logic PCB e Missing battery tab e Case dented e Non functional card reader The chapter titled Classics in the book addresses all the concerns above and more and led to a fantastic looking fully functional HP 65 Figure 2 however in this article we will focus only on the disassembly of the calculator to its individual components Place the calculator face down on a towel to access the screw locations Figure 3 Locate the two tiny rectangles at the top two rubber feet at the bottom and the large label There are two more screws under the label and the reason was for warranty information If the calculator was opened by the owner the label would indicate such
56. following is one such technique but by no means the only one It is however the preferred method of the author You will need for this project A hammer is not required Fig 14 Pressure point for testing fault One stiff foam mouse pad Exacto knife or razor blade Pen knife Adhesive remover citric based Contact cleaner isopropyl alcohol works well Contact cement 11 64 inch drill bit Flat edged pliers Firstly remove the batteries Next slide a thin pen knife blade between the keyboard overlay which is thin aluminum and glued to the keyboard as seen in Figure 15 Start at the bottom as indicated This gives more control over the separation process near the top where the LCD frame 1s The control is required so that the overlay is not damaged at its weakest point The intent is to enter and exit the calculator while leaving no trace Continue maneuvering the blade between the overlay and keyboard and between the keys until you can physically grab the overlay with your Fig 15 Separating the fingers This usually involves separating the two parts up to the third row amp 204 d overlay HP Solve 19 Page 29 Page 7 of 13 from the bottom Once enough of the label has been lifted off the keyboard grasp the free end while firmly holding the calculator on a flat surface Now pull the overlay up and at the same time towards your body Do not pull the overlay upwards greater then 45 degrees to vertical Figure 16
57. forums clubs and discussion groups out there all working individually and as a group creating new ways of repairing and extending the shelf life of HP calculators HP Solve 19 Page 23 Page of 13 Examples from the book There are many examples of the failure of the physical components of the calculators when they survive beyond their design life The HP 41 family suffers from cracked screw posts battery leakage cracked LCD panels and faulty logic PCBs and RAM The card readers from the HP 65 HP 67 HP 97 and the HP 41Cs all suffer from decomposed pinch rollers and faulty dampening couples The Pioneers and Stretch Pioneers fail at the foam pressure contact material and the list goes on These are a function of time plastics and electronics that age and reach their mean time before failure This usually occurs well past the designed life of the calculator Just a note about this article there are many books and resources that will describe the calculator fully The intent here is to illustrate procedures used to open these calculators and repair them The topic however deserves a much larger venue such as a book Let s use the following calculators as examples for this article e The HP 65 represents a calculator from the early era 1974 We will open this calculator and disassemble it to its main components e The HP42S Again we will open the calculator but this time we will isolate the faulty foam pressure pad connecting the keybo
58. ght processing MEMS chip which consists of a large matrix of microscopic addressable movable mirrors perhaps a MEMS based display tactile screen could be devised for this use as well Unless someone can confirm that something like this 1s on the drawing board or has already been done consider the concept of a display consisting of an array of square Surface Elements or perhaps SurfEls for short whose dimensions are 75 by 75 to the inch Each would be part of a MEMS device which could be individually addressed electronically Like the DLP chip these SurfEls would be in two possible states engaged or not engaged whereby when engaged they would provide slight but definite mechanical feedback when pressed with a finger Each one would also contain a 4 by 4 array of addressable e ink pixels on its top surface so as to comprise a 300 DPI display See figure 5 In software the upper portion of the surface could be designated as the calculator display with the lower portion for the virtual keyboard A KML like application could not only specify the position and HP Solve 19 Page 45 Page 4 of 5 Surface Element Consistng of A 454 Atra of pixels QT sri a B00 DPL Figure 5 Left a proposed SurfaceElement shown in the engaged position Right a view of an E ink MEMS based surface with calculator key labels drawn in the designated key positions shape of the virtual keys but could also
59. hese two series you will want to check out some of Geoff s tips Today s HP 41 User Issue 16 described one of the most spectacular calculator systems ever made the HP 41 Peter Platzer read the article and wrote to tell about a typical HP 41 user today What is interesting is that these users want the more advanced functions found on an RPL machine yet they want the RPN user interface of the HP 41 There are many resources provided in the article E Ink Haptic Touch and MEMS Jake Schwartz examines three new technologies that hold promise for calculators Of course HP can t discuss what future technologies they are or are not evaluating Cutting A Circle In Three Equal Pieces Solution Marty had a diet problem described in our last issue that required cutting a circle 10 three equal pieces HP Solve readers submitted their solutions and Wolf Dieter Schone from Germany had the winning submission See his solution and the HP Solve solution Math challenge 2 is included The winner just may have the option of a special prize Is this a simple geometry problem related to silicon molecule model building Numbers Part IT This is the second in our practical Math Review series Numbers is a broad enough topic that it will take three installments before we can get into some more exotic computational topics That is it for this issue I hope you enjoy it If not tell me X lt gt Y Richard hpsolve hp com HP Solve 19 Page 13 Pag
60. iguration of real keys in a numeric keypad below a touchscreen which occupied the remainder of the HP Solve 19 Page 42 Page 1 of 5 top surface Not until around fifteen years later did we see prototypes of the ill fated HP Xpander with virtually the identical layout In 1989 at the annual HP conference that year at Triton College in Melrose Park Illinois where we celebrated the HP41s tenth anniversary by the way a proposal was made suggesting that the HP28 could be enhanced by locating all the hard keys on the right side and having a full touchscreen occupy the entire left side of the clamshell This could allow multiple row softkey menus large graphics a QWERTY keyboard and more It was also the time of the release of the first Sharp Wizard with its keys on one side and touch sensitive clear surface on the other under which a plug in card with function markings denoted to the user the location of soft keys The following year the HP48 debuted with all the HP28 functionality on its single keyboard but alas without the touchscreen ARRYPIARKY PUT GET PUTI GETI SIZE ROM TEN CON IDN RSD CROSS DOT DET ABS RNRM CNRM Rac CK RE IM CONJ NEG NEWLINE PREV ee PINAR STRN LIST REAL zes r E VEW VIEW STACKISTORE IMEMR ALGE STAT PRINT i om g if j LAST CNTRUBRNCH TEST CAT UNIT x tess a a EE gp 07 2 0 MODE
61. ine program listing except for one additional key press and two more than the original inverse sine program Enters program mode and displays the last program previously viewed in the program catalog Place the inverse tangent program into Prgm 3 You may need to press a few times to move the program catalog location until Prgm 3 is displayed Then press Enters program edit mode and displays the first line of the program which will be blank as shown at right since this is anew program Then press the keys needed to access the function in the menu 11 These key presses will access the inverse tangent function in the Math Menu area E aE LLL INPUT This key press enters a STOP command This command ends program execution and returns control to the user To exit program edit mode press ums This returns the HP 30b to the program catalog and now displays Prgm 3 The number of bytes used by Prgm 3 19 shown below it in the display The program uses 8 bytes of memory and has a checksum of 159 To assign this program to the 2 key position enter the program catalog by pressing lam 3 Press to view step 0 of this program where the key assignment will be entered To assign this program to the f key position press f 9 The display should show SH9 where SH9 stands for shift hold 9 which is the shift hold tangent function position This inverse tangent assignment program will now work
62. ix sided die When rolling two standard six sided dice hittp en wikipedia org wiki Dice Seven has a 6 in 36 or 1 6th probability of being rolled 1 6 6 1 2 5 5 2 3 4 or 4 3 the greatest of any number 11 The Millennium Prize Problems http en wikipedia org wiki Millennium Prize Problems are Seven problems in mathematics http en wikipedia org wiki Mathematics that were stated by the Clay Mathematics Institute http en wikipedia org wiki Clay Mathematics Institute 104 2000 Currently six of the problems remain un solved http en wikipedia org wiki Unsolved problems in mathematics We learn our numerals numbers at a very young age Any parent will be exposed and sensitized to this by the many books and materials that are available just about anywhere Most children learn to count at HP Solve 19 Page 58 Page 2 of 11 age two as they learn to talk The critical aspect of this process is learning by rote the order of e 3 In science e 3 5 Psychology e 5 3 Islam 8 In film e 3 1 Physics e 4 In the classical world e 5 4 Judaism 9 In literature 3 2 Chemistry 5 In religion e 5 5 Others 10 In video games 2 e 3 3 Biology e 5 1 Christianity e 6 In music 11 In sports e 3 4 Astronomy e 5 2 Hinduism e 7 In television 12 In other fields the numbers We are able to automatically mentally order numbers Without thinking you will check the completeness of a deck of cards by arranging them by suit and numerical v
63. k RAM and today there is an MLDL available with 1276k of extra storage MLDL2000 from Meindert Kuipers http kuiprs nl hp41 htm MLDL2000 MCODE Machine Code is the native assembler language of the NUT CPU the main processor of the HP 41 HP programmed the OS of the HP 41 in MCODE and later made that code available to the user community It HP Solve 19 Page 39 Page 3 of 4 was ferociously consumed and leveraged to write OS extensions for the HP 41 like the CCD or AdvHepax 5 The AdvHepax module is arguably the most sophisticated extension module written in the 20 century for the HP 41 Produced by VM Electronics in Denmark it offered 16k of OS extensions an additional 16k of storage with a sophisticated file management system and a full service MLDL by far the most compact of its time To this day the techniques employed to achieve all of the above in the size of just one module are par none 6 NoV64 is the brainchild of Diego Diaz and one of the most powerful extensions that is available to the modern user of the HP 41 http www clonix41 org Projects Nov64 Nov64_00 htm It provides 4 blocks of 16k RAM 64k total that are hot swappable via the use of a control word Additionally it provides 48k ROM 16k of which are occupied by a HEPAX while the other two blocks of 16k are again hot swappable via the use of a control word This allows you to have amp different configurations of your HP 41 constantly available each geared towards
64. le 1 shows the selected equations We will use an HP35s for our calculations 1 Unit Circle Area 1 1 4 A 0 785398163398 2 Area of cut 1 3 piece 0 785398163398 3 K 0 261799387799 3 We now know two variables K andr h requires 718 Segment of a Circle values identified HP Solve 19 Page 50 Page 3 of 8 r radius Diameter D that d is known d requires that O is known It seems that h cannot be easily calculated directly EQ 2 shows that we can calculate 9 with what we know so far Solving EQ 2 for Theta requires that we either make a guess trial and error or we use one of the most powerful tools our HP calculator offers HP s Solver 2K 1 2 0 261799387799 0 25 2 09439510239 0 9140 Storing the equation K T SIN T into the HP35s _ list in radian mode allows the Solver to solve for T T T 0 2 6053256746 radians T 0 2 6053256746 radians 2 6053256746 radians T 0 149 274165412 degrees 149 274165412 T 0 149 274165412 degrees when the radian to degree conversion is made with two rls 4 EQ 3 allows d to be calculated 0 5 Cos 2 6053256746 2 d 1 32466042302 5 EQ 4 allows h to be calculated 0 5 1 32466042302 h 0 367533957698 Marty simply measures 36 8 percent of the diameter from the circle on each end of a diameter and he is able to cut the circle into three equal area pieces using parallel cuts perpendicular to the dia
65. lf at the ASEE conference this year stop by the HP exhibit and mention HP Solve for free giveaways while supplies last Come for a free calculator or flash drive and stay to check out our powerful calculators and workstations We specialize in the tools engineers use most Did You Know This HP Solve column is a general collection of assorted tid bits related to HP Calculators HP 50g Software 1 One of the more prolific developers of HP 50g software is Andreas Moeller in Langenhagen Germany North of Hannover He has an extensive web page that provides the details of his many programs One is a browser program for the HP50g Another is a stopwatch program that is far more capable than the one given in One Minute Marvels Programs for the Andreas program 1s called StopWatch C See his HP 49G 496 50G many programs at Fig 7 Andreas Moeller s website offers programs http www software49 emxhome de index html http www software49 amxhome de EnglishSeite01 htm GUISLV You my contact Andreas at Andreas Moeller gmx de 2 Another resource that offers an extensive line of HP50g software is located in Lauben Germany They offer a large selection of scientific and engineering software especially in Physics Electronics Chemistry and mathematics HEUSON SOFTWARE started in 1992 and offers Fig 2 Extensive HP50g software source programs for the HP48SX HP48G G GX HP48GII HP49G HP50G The softwar
66. main failure point of all the card reader calculators The dampening couple and the pinch roller are composed of the same urethane compound which turns to goo It has been speculated that this in fact is a bacterial infection of the rubber Figure 11 sure looks like the result of an agar culture dish in a biology lab In the book you will see methods that repair the dampening couple Figure 12 and change the pinch roller from the Petrie dish specimen above to that pictured in Figure 13 Fig 12 Fabrication of new dampening couple Fig 13 Two methods of replacing the pinch roller urethane The book also tells you how to reassemble and it does not use the term reassembly 16 the opposite of disassembly Mainly because it isn t in all cases therefore explanations are required The HP42S Pioneer The HP42S was introduced in 1988 as a proposed replacement for the 41 series of calculators On the plus side its suite of over 600 functions addition of the solver matrix computations and complex number HP Solve 19 Page 28 Page 6 of 13 ability has made it a must have for collectors as well as professionals many of which still use this calculator 22 years after its introduction On the down side some find the lack of a real time clock I O ability and memory 7 2K to be limiting The user can increase the memory to 32K with the simple swap of the RAM chip and a change 10 jumper switches and this is described in the book For this articl
67. mazon Kindle and Sony E book Reader However it would be great to use in handhelds as well One such idea HP Solve 19 Page 44 Page 3 of 5 proposed in 2005 by Tim Wessman won HP s annual Design the Calculator contest He suggested physical keys surrounded by an E Ink surface where the key labels would appear and remain there even if powered off until changed More recently Samsung has developed a mobile phone called the Alias 2 with E Ink on each key so the labels may change depending upon the currently active application See figure 4 iy EV 0008 1X 000 Verizon Wireless Me i Mey 1 2009 730 AM ee OK rz Shs sd dIOdd See edie 1101 000 gt set lt OK _ ee oB abe pas fu an os 9 Figure 4 Left Tim Wessman s 2005 HP Design A Calculator contest winning entry with E Ink land around blank real keys Right the Samsung Alias 2 mobile phone with E Ink keyboard which changes with applications The Case for MEMS To me the ideal handheld display surface would be a touchscreen with tactile feedback exactly where the application needed it and nowhere else One idea I wondered about was whether this was a problem which might be solved by some sort of MEMS MicroElectroMechanical Systems solution Recalling how Texas Instruments created a totally original approach to projection television with their DLP digital li
68. meter The correct value of h is very close to one third 0 333333333333 which is 9 30543250458 percent too low Table 1 Equation Relationships of the variables shown in figure 1 Variables A is the area of the circle r is the radius of the circle c 1s the chord length of a segment of a circle K is the area of a segment of a circle as shown 10 figure one s 1s the arc length of the segment h is the height of the chord at the midpoint d is the distance from the chord to the center of the circle 0 is Theta the angle subtended by the arc length measured in radians EQ 1 Circle Area nr also 702 4 EQ 2 K r 0 9100 isolating 0 2K 0 9100 2 i EQ 3 d rCos 0 2 EQ 4 h r d Is this answer correct How do you actually know How could you confirm this by measuring the circle and cut area with minimum effort What tool s would you need Here Is the Editor s Experimental Solution One technique is to obtain a large uniform thickness and composition piece of heavy card stock or paste board similar to what 16 used for the back of a writing tablet Alternately you could use a thin piece of sheet metal and a tin snips A piece of wood and a saw are unsuitable because of the lost saw dust Get the heaviest material you can to increase the resolution of the measurement 1 Draw the largest circle you can and draw a diameter and one of the two cut lines 2 Cut out the circle carefully and weigh it Record
69. mid section by two power wires When the mid section is lifted the keyboard PCB will want to pivot at the top allowing the bottom to swing out so carefully lift the mid section away keeping the keyboard PCB in place with the mid section Once the mid section is removed the top shell will remain behind with the keys floating in their respective holes covered by a plastic grid and thin sheet of clear plastic The two sliding switches will also be residing 10 their respective slots in the top shell or attached via hardened silicon grease to the keyboard PCB ip j Locate the two power wires that connect the keyboard PCB to the mid Fig 6 Internal components section of the calculator These vary in colour in differing production and screw locations Series but are usually marked with red and black to differentiate the two Trace them back to the keyboard PCB and note their location Some of these are soldered to the board and some are connected via a plug system In one production version the wires were swapped as to their ca PEFFEEEEEEESSAREFEFEE polarity It is important to remember the colour reference on the wire to its location as reversing these by accident will destroy the logic lt 4 PCB they are the power wires Unsolder these wires after noting their respective positions to free the keyboard PCB Figure 8 The same figure also illustrates one method of cleaning debris and corrosion between the keyboard contacts The let
70. miter or separator character DUP Copy the level 1 object OVER Copy the level 2 object PICK Copy the level n object Copy the first n objects Duplicate X into Y Recover last argument LASTARG Correct an error LAST STACK Copy X Copy Y Counting Objects Count the number of objects on the stack Object Recovery Return the arguments used by the last command Restore the stack to its state before ENTER Fig 2 RPN amp RPL Stack operations Fig 6 RPL open ended stack and more powerful stack operations From a programming perspective there is a big contrast between the programs are viewed RPN programs are line oriented Each instruction has a program line number This structure dictates that programs instructions are numbered and they are listed in order like a list RPL programs are simply a series of instructions and numbering them has no meaning What has meaning is grouping them as objects programs This is a major learning curve challenge for the RPN programmer who wants to become an RPL programmer RPL 1s different and more powerful Making the change is a personal choice and what you want to accomplish with your programming RPN Tips 19 Notes 1 Common community knowledge knows RPL as Reversed Polish LISP LISP is an acronym for List Processing Language LISP as an acronym may have many different meanings e g Language for Internet Scripting and Programming Local Internet Service Provider etc The memo
71. nder software control e g HP50g modifications must also be considered Shorter programs generally run faster than long programs but not always When calculator speeds are discussed the devil is in the details See the long multi model speed claims list at http www hpmuseum ore cegi sys cgiwrap hpmuseum articles cg1 read 700 About the Author Gene Wright is the author of textbook Quantitative Analysis for Business a business math textbook using the HP 1OBII and HP 12C available from Amazon com He is also a video lecturer for a CFA exam review course A former teacher at Lipscomb University in Nashville Tennessee he now works for a consumer electronics company Gene has written many articles on HP calculators and serves on the annual HHC committee HP Solve 19 page 10 Page 7 of 7 Regular Columns From The Editor Article Regular Columns From The Editor Issue 19 As HP Solve grows the normal seven article structure will be divided into multiple topics under a single grouping This will allow more articles on more topics This is the nature of the software we use The first change is combining the shorter regular columns RPN Tips and One Minute Marvels into a enti more generic topic Two other columns will also be part of this slot They are Community News content obvious and Did You Know a general collection of assorted tid bits All readers are asked to contribute to HP Solve by alerting me t
72. ns did not Marty went to the highly educated group that he ate lunch with every day and posed the mathematical problem He was sure that they understood what he was asking but none of them would help They gave a few ideas but no answers What he needed was a simple ratio HP Solve 19 Page 53 Page 6 of 8 Marty was reminded of this 47 year old problem because he recently unpacked the Styrofoam ball shown in figure one above It had only four holes in it He found four wood skewers and they fit perfectly into the holes He also found a cardboard fixture that he had made and then it all made sense Forty seven years ago Marty had solved the four equally spaced point location on a given sphere problem with sphere diameter D by constructing a polyhedron with four triangular faces e g a pyramid with a triangular base The idea is to drill a small hole in the center of each triangular face and hinging one side to open and insert the sphere to use as a fixture Marty wanted the simplest fixture Fig 2 Equilateral triangles constructed by drawing two parallel lines LI and L2 with a spacing of S design construction method by drawing two parallel lines on cardboard or sheet metal and then drawing the sixty degree angles to cut the four triangles See figure two above Marty used clear packing tape for the hinge The three edges are spaced by the thickness of the material used for the sides Smaller diameter toothpicks are
73. o any new activity happening in the HP User Community HPUC The time for reader feedback from issue 18 has been short as we get back into the even month publishing schedule I really want to hear from you and I have responded to those of you who have already sent me emails One of them was from Peter Platzer Peter is an active HP calculator user and our email exchanges has resulted in an article on today s use of the HP 41 as a result of the HP 41 article in HP Solve issue 16 New HP calculator users especially students will find the mentioning of older HP models curious You will understand as you log a few hundred hours of HP calculator usage and you master your machine The machine tends to grow on you As you learn about the depth of design that HP has put into so many of its models you will come to depend on your machine Before you know it years have passed and you too will want to know the latest on your older model You may have also noticed the change on the Issue list on the HP Solve website The term Volume is changed to Issue and all references to an HP Solve Volume will be the same number as the Issue number We have also assembled the newsletter into a single pdf file so you may down load the issue to your computer This feature will become more important as the information content increases As I mentioned in the last issue I want HP Solve to be a technical resource as well as an educational reading newsletter Here are
74. o underlined commands 10 the Electronic Stopwatch program to add minutes and hours tagging Alternately you may key the commands in their place to make one program The program is reproduced below for reference SW lt lt 1 FIX TICKS IF 5 FS C THEN t RCL BOR 8192 Sec TAG ELSE t STO 5 SF END gt gt 21 Commands 100 0 Bytes 69F7h SWUa lt lt IF DUP 60 lt THEN Sec ELSE 60 IF DUP 60 lt THEN Min ELSE 60 Hr END END TAG gt gt 22 commands 122 5 Bytes 2DADh How the program works SWUa starts with the time in seconds on level one An IF THEN ELSE structure is used as indicated by the IF A copy of the seconds is made with DUP and 60 is placed on level one A comparison is made and if the seconds value is less than 60 seconds the THEN clause 16 executed by THEN The text string Sec is placed on the stack If the seconds value is 60 or higher the ELSE clause is executed The comparison with 60 consumes one of the seconds values made with the DUP The ELSE clause places 60 on the stack and the seconds is divided to convert to minutes by the As second IF clause is executed and a copy of the minutes value is made with the DUP 60 is placed on the stack and a less than comparison is again made If the minutes value is less than 60 the THEN clause is executed and the text string Min is put on the stack If the IF clause comparison lt is 60 or greater the ELSE clau
75. ods for grouping the digits to allow the eye to more easily discern count the number of digits The method used with a period radix is to add a comma separator every three digits An example is 35 million dollars In the US the radix is a decimal point and the 1 000 s separator is a comma 35 million dollars is 35 000 000 00 In Europe this same number is expressed and calculator displayed as 35 000 000 00 If you are used to seeing one format the other seems very strange and confusing Most HP calculators may be set to display the numbers in either format The second common method for conveniently dealing with long strings of digits uses a space inserted every five digits Table one on the first page uses this method Calculators do not use this format unless specifically user programmed to display numbers 10 this way HP calculators have various display modes to show the number 10 a format that is most suitable for the application The most common modes are fixed scientific and engineering Each mode requires you to specify the number of digits The display mode setting does not change the number it only changes the way it is shown in the display and you may change the display mode at any time The display value is rounded to the number of display mode set decimal places Some machines have a display mode called ALL which may be also found on the HP35s Fixed mode is most popular with business users and this 16 usually the default mod
76. of this math Review The most important question to ask is Do other cal culators get a better answer In order to make a test your self you must take the square root clear the machine and enter the result for each calculation because many other machines retain the guard digits and the error propagates The accuracy aspect of a calculator 16 a topic beyond of this brief numbers review Rounding is another complicated and confusing issue Suppose you have the following three numbers examples A C to round to two decimal places I have added two spaces at the point where the number is to be rounded A 13 98 132411 B 13 98 532411 C 13 98 932411 In the first case the result is clearly 13 98 because the following digits are very small so they are dropped In the last case the result 1s clearly 13 99 because the following digits are very large so 1 is added It is the middle case B where there is an issue The 5 is right in the middle of 13 98 and 13 99 In other words there is a tie What is the best method of treating the 5 case You could argue that since the HP Solve 19 Page 64 Page 8 of 11 decimal digits following the five are so small that you should drop it You could dream up all kinds of complicated rules to decide this middle 5 case and you will find many rules if you research the rounding issue When rounding you first consider the number of decimal digits you are rounding to If it is three digits th
77. oks is soft bound 2 x 8 248 pages A review by the Atlanta Journal Constitution puts the book into perspective Mathematicians contrary to popular misconceptions are often the most lucid of writ ers Bertrand Russell won a Nobel prize not in mathematics but in literature and Seife is a welcome example He writes with an understated charm that takes account of human fear the mistakes of geniuses and the mind s grandest ambitions 4 The Rule Of Nine Simplified and Expanded by William Wallace Jr copyrighted 1959 is published by the United States Naval Institute The booklet is 6 x 9 and 27 pages ISBN 0 87021 555 8 Library of Congress Catalog Card No 59 12077 second printing 1970 The essence of the rule is a method system of reducing all numbers to a single digit Is the number 2 835 divisible by 9 Yes because the sum of the digits 2 8 3 5 18 and the sum of these digits 1 8 9 Addition subtraction multiplication and division operations may be verified by applying the rule of nine This is an example of accuracy checking math before we had calculators Now our mistakes are those of entering the numbers into the calculator e g pressing the wrong keys There is a newer version of a similar book by another author 5 000 numbers to images in my article file so I may quickly find what I need While proofing an article I note the figure number open and find the image edit it save it and then insert the ne
78. olve 19 Page 38 Page 2 of 4 by Angel Martin one of the most prolific MCODE developers of the HP community A very comfortable unit conversion module that covers 100 units and 10 important constants MLDL2000 Fig 3 One of the most sophisticated MLDL s devices of its Fig 4 The modern MLDL2000 developed by time the ProfiSet was produced by the German Company Meindert Kuipers This innocuous little device in MBK It provided a full 32k of user programmable RAM as the shell of a card reader provides 255 4k pages of well as 16k of ROM with one of the most comfortable ROM and 63 4k pages of user programmable RAM operating systems to write MCODE as well as use the 32k Enough storage capacity to virtually hold all RAM for extended program ASCII file or data storage ROM s ever developed for the HP 41 Today s HP 41 User Notes 0 1 2 3 4 The HP 41 has been an inspiration for its users for 30 years to such an extent that a microprocessor designer Monte J Dalrymple has redesigned the NUT processor to increase its speed and improve its overall performance You may find the technical details at http Avwww systemyde com pdf newt pdf The PPC ROM project was undertaken in 1979 80 by HP Calculator users and members of the HP calculator club called PPC Hundreds of programmers contributed to the 153 basic building block routines program med into an 8 KB plug in module for the HP 41 series of machines
79. ou can access all the HP material you want but never have to receive information you don t want Step 4 You may be prompted to fill information about your HP calculator such as model and serial number If you don t have the serial number just enter 000000000 This just lets us know what calculators our HP fans are using so that we can better tailor our offers and newsletters to your needs Step 5 Welcome to the HP Calculator Club You will now receive our bi monthly newsletter and you will also have access to HP discounts special offers and complimentary applications applets for your HP calculator You can give us feedback about our calculators through the HP Calculator Forum Please feel free to let us know what you would like to see from us on the HP Calculator Club site and we will do our best to oblige HP Solve 19 Page 71 Page 1 of 4 How to Join the HP Calculator Club and Sign Up to Receive HP Solve our Free Bi monthly Calculator Newsletter Step 1 Go to www hp com calculators and click on the newsletter link on the right side of the page gt Calculator HP Calculators Microsoft Internet Explorer provided by Hewlett Packard File Edit View Favorites Tools Hel Bookmarks v Settings Q Web Search Upgrade your Toolbar Now i GS Ey y U http Avwew hp com country us en prodserv calculator htm HP Games HP Create Coupons com We BR Bcslculstor H
80. our cut triangles are configured The marking drill holes are located by drawing a line normal to the side at the half way point on two sides The center tangent point is where the lines intersect Figure four shows his fixture with the two inch diameter sphere inside The cardboard was obviously cut from an orange and black sign Fig 4 Styrofoam sphere in fixture with four holes to mark Fig 3 Fixture with marking hole locations shown the equally spaced locations on the sphere Extra points are possible if multiple solutions are provided or if derivations of the solution equation ratio are provided Remember just getting the answer is not enough to distinguish your result from everyone else Send your entry to the Editor The dead line is before the next issue is posted Marty is still wondering how he derived the simple ratio after nearly five decades He is so curious that he just may be able to come up with a prize for the HP Solve reader who sends in a clear simple and readable solution HP Solve 19 Page 55 Page 8 of 8 Fundamentals of Applied Math Series 2 Previous Article Next gt 2 in Fundamentals of Applied Math Series Numbers Part Il Richard J Nelson Introduction Numbers Part I in HP Solve Issue 18 outlined the guidelines for this series and set the scene by asking what is the best number to put into a calculator display for a photograph note at the end A
81. owever has yet to be determined and is being debated in the HPUC Las Vegas Phoenix Ft Collins and Chicago are the leading candidates HP Solve readers who want to know when the decision is made may find the information at the HHC web site at http hhuc us More serious users may sign up on the HHC List at http lists brouhaha com mailman listinfo hhce to receive email related to the Conference Once you sign up you may also post to the list to ask questions participate 10 discussions etc Most HHC attendees belong to the list maintained by Eric Smith HP Museum This site is where much of the HPUC goes to get the most timely Navigation information of current topics of interest and the older technical e What s New 11 18 09 information that a Museum would be expected to provide Check out Search the Museum 000 Manuals on CD DVD 11 18 09 http www hpmuseum org Escape fiemes Contact the Curator The Museum of HP Calculators displays and describes Hewlett Packard aA C Areas calculators introduced from 1968 to 1986 plus a few interesting later e HP Fonm models There are also sections on calculating machines and slide rules peepee as well as sections for buying and selling HP calculators an HP timeline HP Forum Archives e Articles Forum collecting information and a software library oop eames Biographies A daily discussion forum is open to everyone and you will find it on the Clas
82. ows the many other aspects of numbers that are also included What is your favorite number The reader may explore the history of how we have come to shape our numer als zero to nine by reading the many references provided by Wikipedia and other Internet references Zero 19 such an important topic in itself that a 248 page book has been written on the sub ject See figure two note at the end A simplified history of our numerals is shown on page 68 of the book See fig ure four below THE RULE OF NINE Simplified and Expanded Nine also has special value and a booklet has been written about The rule of nine See figure three This installment of the Math Review Fig 2 This entire book is ded series will focus on numbers as related icated to the concept of zero _ tg their use on our calculators Fig 3 9 checks x math HP Solve 19 Page 57 Page of 11 1 Seven is the fourth prime number http en wikipedia org wiki Prime number It is not only a Mersenne prime niip en wikipedia org wiki Mersenne_prime Since 2 1 7 but also a double Mersenne prime http en wikipedia org wiki Double Mersenne_prime since it is itself the exponent for another Mersenne prime 127 Itis also 8 Newman Shanks Williams prime http en wikipedia org wiki Newman Shanks Williams prime a Woodall prime http en wikipedia org wiki Woodall_ prime a factorial prime http en wikipedia org wiki Fac
83. place significant zeroes behind a decimal point 8 200 x 10 has four significant digits 8 20 x 10 has three significant digits 8 2 x 10 has two significant digits HP Solve 19 Page 65 Page 9 of 11 Understanding and using significant digits and rounding are two vital aspects of dealing with numbers when we use calculators N11 Rational or Irrational Numbers This important topic will be discussed 10 Part III N12 Ordered Pair Numbers This important topic rectangular coordinate points complex numbers polar coordinates and vectors will be discussed in Part III N13 Prime Numbers This important topic will be briefly discussed in Part III Conclusion Calculators by their very nature deal with numbers We must understand numbers if we are going to cor rectly and accurately use a calculator to do the hard work of number crunching Ten aspects of numbers are discussed 10 part II of a three part series The short review includes references and links to more ad vanced aspects of the topics reviewed N1 Cardinal and Ordinal Numbers N2 Counting Numbers N3 Odd or Even Numbers N4 Negative or Positive Numbers N5 Integer or Decimal Numbers N6 Real Numbers N7 Being Consistent N8 Formatting and Expressing Numbers N9 Precision Accuracy and Rounding N10 Significant digits The last part Numbers HI of the Number series will focus on the following topics N11 Rational or Irrational Numbers N12 O
84. provide image data for the portions of the E ink display over each key When activated the Surface Elements in the designated key positions would be engaged and the images drawn Pressing the surface between the designated keys would provide no feedback but pressing in the area of a key would result in somewhat of a click like feel Should key presses cause a mode change the drawn keys could be changed accordingly In fact if necessary changing modes could completely change the virtual keyboard with respect to the position and number of keys as well As a result a machine could hold multiple calculator emulators in its firmware and could change between them via user commands with virtual tactile keyboards changing at the same time Imagine embedding Eric Smith s Nonpareil emulator on a box like this with an opening mode screen where the functions on the keyboard are labeled Classic Woodstock Spice Voyager Pioneer etc and after making a selection a subsequent keyboard would be labeled with calculator model numbers That might be the HP fanatic s ultimate dream machine About the Author Jake Schwartz has been an HP calculator fan since 1971 after first trying the HP9810A desktop RPN machine at a co op job at RCA in New Jersey He has owned most of the scientific top of the line handhelds since the HP35A in the early 1973 joined the PPC Calculator Club in 1977 and contributed to many of the clubs since
85. r forum Customize your computers with HP Calculator screensavers and backgrounds Find out what others are saying and join the discussion in our fourm designed just for Calculator Club members HP discounts amp special offers Get access to both HP and HP Calculator discounts and bundles here You can also find out how to get discounts on bulk orders and other special offers Welcome to the HP Calculator Club You will now receive our bi monthly newsletter and you will also have access to HP discounts soecial offers and complimentary applet downloads for your HP calculator You can give us feedback about our calculators through the HP Calculator Forum Feel free to let us know what you would like to see from us On the HP Calculator Club site and we will do our best to oblige HP Solve 19 Page 74 Page 4 of 4
86. r must provide the register number In an RPL system the register number an object must be on the stack data first when the store key is pressed This will seem quite confusing and unnatural for an experienced RPN user A key feature of RPL as a language 1s that it is structured RPN programming languages are not This means that RPN has a GOTO instruction which allows what is often called spaghetti code programming RPL requires a single entry and exit point for each code sequence so uncontrolled jumping around is not permitted RPN uses simple assembly type of instructions and RPL uses higher level language type of instructions RPL operates quite differently than RPN internally and that is what gives the RPL machines their incredibly efficient computational power Because RPL and RPN operate in a postfix mode and RPL was required for the next generation of HP calculators RPN as implemented on RPL machines will behave a little differently The RPL system is also used on machines that are not obviously RPL because it 1s easier for HP to use a common core for their machines This means that the legacy RPN user will find a few oddities in the way their latest HP calculator works in RPN mode HP4l HP48 Transitions SS r 1 h ah BESEEEREBEEEEEESEE BEEBE EEEEALEL William C Wickes Fig 4 Bill Wickes Transitions book is out of print but copies may some times be found on th
87. rable meaning that is relevant to HP calculator users is Lots of Insidious and Silly Parentheses See the Wikipedia article at http en wikipedia org wiki RPL_ 2 amp programming_language 29 2 HP calculator generations as used here are defined as Genl HP65 67 Gen2 HP 41 Gen3 HP 71 75 and Gen4 HP28 48 49 50 Gen4 introduced the RPL era of HP calculators 3 41 48 Transitions is 6 1 4 x 8 1 4 plastic spiral bound 9 02 255 gr and 149 pages Published by Larken Publications of Corvallis OR 41 48 Transitions is no longer in print and the Publisher is gone 3 HP Solve 19 Page 17 Page 6 of 10 One Minute Marvels HP 48 One Minute Marvel No 6 Electronic Stopwatch Time Units One Minute Marvels are short efficient unusual and fun HP 48 programs that may be entered into your machine in a minute or less These programs were developed on the HP 48 but they will usually run on the HP 49 and HP 50 as well Note the HP48 byte count 16 for the program only In Issue 18 an electronics stop watch One Minute Marvel OMM was given to turn your calculator into an electronic stopwatch The time displayed by this program was in seconds Because you do not need your machine to be on while timing the OMM stopwatch may be used for longer periods and it may be easily enhanced to automatically convert times greater than 60 seconds to minutes or hours This OMM may be called in place of the tw
88. ram editing mode and return to the program catalog press lama Ral To exit the program catalog and return to calculation mode press fwe Fig 1 HP 30b shown with programming overlay At different places within a program you can insert a Label LBL command A label defines a location HP Solve 19 Page 4 Page 1 of 7 to which program control may be transferred The HP 30b can handle up to 100 labels within the entire program memory These labels are a two digit numeric value from 00 to 99 No label can be used more than once which makes each label a global label and defined only once within the global program memory space If you attempt to enter a label that has already been used a message saying Exists will be briefly displayed When a program is displayed a number will be shown below it indicating how many bytes are used If the program name is shown in reverse video then the program has been assigned to a key and can be executed by pressing the appropriate key combination even when in calculation mode as shown in the image at right This article will give three examples of making such assignments Example 1 The HP 30b has the three basic trigonometry functions sine cosine and tangent on the keyboard The inverse trigonometry functions are 10 the Math menu however as shown below If you need to use the inverse trigonometry functions often you can assign these functions to the shift hold positions of the three
89. rdered Pair Numbers N13 Prime Numbers 1 The photographic calculator display question was actually the basis for a contest held on the Internet The winner was Joseph K Horn who provided a Meta solution He wanted very specific restrictions on the number and he decided that he would provide all solutions depending on the restrictions you may apply You may see his number answer at http holyjoe ne hhc2009 contestl htm All seven contest related documents may also be found at this link 2 Technically the numeric key pad layout hasn t been quite as stable as it might first appear The non zero digit order has been consistent but the bottom row containing the zero and decimal point has moved around on the nearly 100 models of HP calculators Jake Schwartz has extensively analyzed HP s calculator keyboards and you may find the results in an HP Handheld Conference HHC paper titled HHC 2000 Survey of HP Cal culator numeric keypads http www pahhe org 2010 Articles HHC2000 20A 20Survey 200f 20HP 20Numeric 20Keypads pdf e tables in his paper also include model attributes such as usage business Scientific etc logic system pro The tabl his paper al lud del attribut h ge b t tc logic system p grammability solver CHS exponent and ENTER keys HP Solve 19 Page 66 Page 10 of 11 3 ZERO The biography of a Dangerous Idea by Charles Seife copyrighted Charles Seife 2000 and published by Penguin Bo
90. repaired the odd HP 41C or HP IL peripheral and learned that esoteric programming language MCODE Eventually I started to give back to this most collegial community by writing my very own module multiprecision arithmetic up to 1000 digits written in MCODE see http www hpmuseum org cgi sys cgiwrap hpmuseum archv018 cgi read 143386 Hand in hand with these exploits I built a small but respectable collection acquiring items that I could only dream of back when I was first introduced to the HP 41 Focusing on literature MLDL devices and HP IL peripherals I acquire almost solely items that I want to learn use and program with What is most amazing about the HP 41 is that even today 30 years after its introduction there continue to be brilliant engineers around the world that encouraged and inspired by its legendary quality develop new hardware extensions Leveraging today s technology of PICs and flash they continue to breathe life into this little machine of wonder In the pictures you can see the development of MLDL devices over time from the early pioneering devices bulky and crude to the latest devices that can store basically any and all software and modules that have ever been developed for the 41 The I O capabilities of the HP 41 allow us to do some very modern tricks such as connecting the calculator and steering an X 10 network in the house running an HTTP server albeit a very slow one or connecting the HP 41 to a PC via USB
91. riting Remove all remnants of the old adhesive then wash the overlay in soap and water with a soft cloth Figure 32 While waiting for the overlay to dry and using a good set of tweezers and tooth picks remove the adhesive from the keyboard Now that the keyboard and keyboard overlay are clean of any remaining adhesive we can remove the kinks from the overlay and soften the warp As with the HP 65 label insert the now clean and dry keyboard overlay between two heavy sheets of vinyl Note that the overlay is not flat but has compound curves at the LCD frame Leave the LCD frame outside the vinyl sleeve during this process Ensure the keyboard overlay is face up and rub the vinyl wrapped overlay with the under side of a large spoon Remember to stay away from the LCD frame part of the overlay The crimps and creases incurred while removing the keyboard overlay will disappear Flip the overlay over and rub the back side now You want to place a tiny convex curve on the p g 32 Comparison of overlays keyboard overlay when it is facing upwards This allows the corners to lie flat when the overlay is glued in position Look at Figure 32 to see a slightly curved glue free overlay example at the left Compare this to the warped adhesive covered overlay on the right If the LCD frame part of the overlay is crimped straighten it by placing the overlay face down and rub the area from behind gently with the flat end of a rounded dinner knife handle
92. rogram Remember that if you make a mistake while entering a MSG you can press at any time before you press and the character at the end of the message will be deleted Note that the MSG command is perhaps most useful to enter a string of characters in a program to display a prompt to the user before the program stops for input This prompting message can help the user know what values to enter before resuming program execution The use of the MSG command here to give a title to a program 10 the program catalog 19 simply another use of this function 0 The HP30b is not only fast it is faster than most other HP calculators An HP Museum posting is dedicated to comparative hand held speeds using what is called the N Queens Problem This involves processing an 8x8 matrix Gene says that the HP30b runs the test program in 11 seconds Here are the reports on the HP Museum for other HP calculators HP 11C in 3 830 seconds HP38G in 859 seconds HP42S in 732 seconds HP48GX in 217 seconds HP50g in 90 seconds These numbers must be taken with reservation A calculator s speed will depend on two basic factors hardware vs software For example the HP30b searches from the top of memory down to the bottom If you have a full program memory and your speed program is last it will appear to run slower than if it was first There are many tests provided for the same machine with each user trying to hold the speed record so speed altering hardware some u
93. s to a system of the three unkowns h and s and the three equations 2 3a 2 s h 92 gt HP Solve 19 Page 49 Page 2 of 8 Inserting VI and VII in V finally gives a single equation for 2 2 cos 2 a E e 0 O E re 2 r 3s YF 2 9 4 p2 fp ara 6 PP eos This equation can again be rewritten leading to in 2 cos 2 Ga 22 ae or sin 7 cos v y a with a 2y Typing the latter equation into the calculator and using NUM SLV gives the result for y y 1 3026628373 or 2 6053256746 in degrees 149 274165412 h is thus determined to be h r cos 2 0 264932084603 r The thickness of the first slice d 1s d r h hi z co 0 735067915397 r Thus the desired ratio AG to AB is a ca 0 367533957698 AB 2r The result can be checked independently by integrating a quarter circle of radius r 1 h 2f vl x dx a N 0 0 523598775599 0 f yl x dx x 0 0 523598775599 0 523598775598 showing that the above result is correct Here Is the Editor s Math Solution Figure one at the right shows the relationships of a segment of a circle The chord is one of the cuts and the second cut is a mirror image The math challenge 1 is to calculate h The first step 16 to check a math text book reference book or the Internet to get the equations that show how these values are related Let s use a circle of unit diameter D 1 Tab
94. se 1s executed and 60 19 placed on the stack As with the first comparison one of the minutes values was consumed Next 60 1s placed on the stack and the minutes value is divided and the stack has the seconds value in hours on the stack Since two IF THEN ELSE structures were executed there must be two END s Depending on the value on the stack Sec Min or Hr it is tagged with the TAG command and the program stops Brian Walsh of Chicago Illinois suggests that SWUa can be rewritten to save 15 bytes by using the IFTE function as SWUb lt lt DUP 60 lt Sec 60 DUP 60 lt Min 60 Hr IFTE IFTE TAG gt gt 18 commands 107 5 bytes E644h checksum HP Solve 19 Page 18 Page 7 of 10 SWUb is 15 bytes shorter and faster than SWUa This is a good example of the use of the short form IF THEN ELSE END structure IFTE Readers who understand how the IFTE structures work may easily further enhance the units to add days weeks months and years if desired What would be the maximum time this program could indicate Hint It 1s thousands of years Community News HP Handheld Conference HHC2010 The longest running since 1979 HP User Community activity is the HHC This annual Conference has been described in HP Solve Issue 10 HHC 2008 and issue 16 HHC 2009 The Conference will be held on September 25 amp 26 2010 this 19 the last weekend of September The location h
95. sified Ads center right side of the opening page See example at the right Buying Ads without Auctions one of the HP Museum CDs is well worth having for the Owner s Manuals TEE details 10 photographs of the many machines supported Newsgroup http www usenext com HPCC The British User s group has published Datafile for many years You may explore their website at http www hpcc org hpcalc org Hpcalc org is the premier source of software for and information about the HP 50 HP 49 HP 48 and HP 28 RPN programmable graphic calculators and the HP 38G HP 39 and HP 40 programmable graphic calculators with 7078 files by 2136 authors and 2969 screenshots totaling 697 9MB HP Solve 19 Page 19 Page 8 of 10 Calling all Engineering Educators and Professionals HP Calculators will be presenting at the exposition of the American Society for Engineering Educators ASEE annual conference June 20 23 in Louisville Kentucky The Annual ASEE conference is a place where educators and professionals from all disciplines of engineering come to exchange ideas develop 21 century teaching methods and network with like minded colleagues ASEE members include 11 000 college and university professors 90 of all engineering deans in the U S and over 10 000 corporate and government representatives To learn more about this distinguished professional organization events and publications visit www asee org Also 11 you find yourse
96. sk symbol for multiplication c 15 2 1 15 as expressed as powers of two d 15 1 5x10 as expressed using scientific notation 6 15 15 00 may be expressed to imply two decimal places of precision 1 15 30 2 as expressed as a fraction g Half a minute past noon as a time may be expressed as 12 00 30 using the form HHMMSS h Dates are another example of the variability to deal with boredom of using numbers Most readers have experienced the set up process with most hand held devices that have a built in calendar In the US the format is MMDDYYYY In Europe the format is DDMMYYYY If you spell out the month and use numbers for the day and year you must insert a separator between the day and year to avoid confusion HP Solve 19 Page 63 Page 7 of 11 If you may abbreviate the year to two digits the format YYMMDD provides a nice six digit date that may be easily and correctly sorted by date The beginning of the year is 100101 mid year is 100701 and the last day of the year is 101231 This 1s the Japanese custom to display dates N9 Precision Accuracy and Rounding Calculator displays will display a resolution of 8 10 or 12 digits Most users expect that the answer they see in the display is correct 1 e accurate If the display is 12 digits and the answer 0112 1 41421 3562 373095 what should the last digit in the 12 digit display be Based on the answer above it should be a 7 and most machines will show a se
97. ters A and B refer to the sliding switch contacts which should be cleaned and lubricated with silicon grease points highlighted FIEF I Do aS 5 t 2 Fig 10 Card reader motor coupling and worm gear sa Fig 8 Keyboard PCB switch Fig 9 Card reader components Fig 11 Deteriorated pinch roller location and cleaning method HP Solve 19 Page 27 Page 5 of 13 The card reader is part of the mid section and its parts are listed in Figure 9 Motor Power wires associated with motor Dampening couple Eccentric cam Worm gear Card reader head Pinch roller Card reader logic PCB TaATTMUOWS As we have completely disassembled the calculator to its main components this would be a good point to stop with this disassembly The entire HP 65 has been laid bare and to continue with sub component disassembly would involve another 11 pages The book goes into much more detail and the chapter labeled Classics 16 23 pages in length with 37 figures One interesting point about the HP 65 which applies to the other card reader versions including the HP 41C involves the card reader dampening couple and the pinch roller In Figure 10 the individual parts of the card reader drive system are laid out e A Motor shaft e B Aluminum sleeve e C Urethane dampener D Worm gear Figure 11 shows a deteriorated urethane pinch roller The reason I have included these is to point out the
98. the articles in this issue HP30b Key Assignments Gene Wright describes a step by step procedure to place any deep menu function on the key of your choice This makes the machine easier and more convenient to use The article also provides a speed comparison with several other HP calculators and it looks like it 16 about the fastest machine to date See the last page of Gene s article The HP30b may be purchased at Office Depot beginning in mid August Regular Columns This collection of repeating columns is new Here is the Issue 19 list From the editor This column provides feedback and commentary from the editor A letter from down under mentions HPUC activity in Australia e RPN Tip 19 One of the major changes HP has made in computational excellence is expanding RPN into RPL and this 16 the topic of RPN Tip 19 The Enter key collection has them identified A photo of a rare HP 35A photo is included HP Solve 19 Page 12 Page of 10 One Minute Marvels This OMM on stopwatch units was promised in Issue 18 Community News The three primary HPUC websites are listed and the HHC conference update 18 provided Did You Know HP50g software sources are listed Calculator Restorations Geoff Quickfall from Canada is writing a book on restoring HP calculators He provides a preview in his restorations article The HP Classic and Pioneer series are described with 35 photographs If you have one of the 17 models of t
99. the same way the inverse sine program does Example 4 Change the inverse sine program so that step 1 contains the MSG INV SIN so that the program will show those characters as a title in the program catalog listing Remember that to move the character position to a numeric digit as a letter in a message press the corresponding numeric key To move to an press Pressing moves to the character Pressing moves the character HP Solve 19 page 8 Page 5 of 7 position to a space The arithmetic operators move the character position to the corresponding operator character Press to select the displayed character and prepare to enter another character Press to select the displayed character and terminate character entry A maximum of 8 characters may be entered as a message To modify the program do the following i INPUT L ga on 000 og v Cc LIL riz g v z AD f o 00 O AA Gil o lt N p D ve Enters program mode and displays the last program previously INPUT viewed in the program catalog Press until Prgm 1 is shown in the display Itis shown in reverse video to indicate that it is assigned to a key Then press aTa a 20 Enters program edit mode and the first line of Prgm 1 the command to enter the Math menu Then press Inserts the MSG command at the presently displaye
100. them onto the keyboard As shown in the picture at right the HP 30b has additional functions assigned to the keys that are program only functions Other than the Black Scholes function shown as Black S which is not a program function but a financial function these functions are not printed or labeled on the actual HP 30b itself However Pram G an overlay is provided that lays over the top rows of keys Fate Tw that help indicate how these functions are mapped to the a keys Each of these functions 19 inserted into a program by pressing the shift key and holding it down while pressing the key under which the program function is displayed For example to insert a LBL label command press m and while holding it down press In these learning modules describing programming this will be shown as f Pressing that key combination will insert a LBL instruction into a program in program edit mode Pressing that key combination in calculation mode will do nothing There are 10 numbered slots available for programs numbered from 0 to 9 These are displayed 10 the program catalog which is viewed by pressing m In the image above the program catalog is displayed showing Prgm 0 or program 0 Pressing the or keys will scroll through the list of 10 programs Pressing will enter the selected program allowing you to view the program steps stored in that program slot or to change the program steps To exit this prog
101. this is dependent on how good the alignment of the tabs is to the slots they fit into Once off the LCD panel and keyboard flex PCB are exposed Under the keyboard flex PCB is a 4 2cm long strip of grey foam Figure 25 This is Fv gt Fig 25 Removing the foam under the keyboard ribbon Fig 26 foam removed use as template for replacement foam the culprit Over the years it has been compressed to the point where it no longer fulfills its designed purpose to press the keyboard flex PCB into the contact points of the logic PCB A combination of double sided adhesive and pressure holds this foam in place Using tweezers and starting at either side e Lift the keyboard flex PCB out of the way e Grasp the foam in the tweezers Figure 25 e Pull the foam out as much as possible as some may adhere to the bottom of the rectangular frame holding it e Cut new foam using the dimensions of the original from the stiff mouse pad or suitable replacement foam I make mine slightly taller and thicker The caveat is that the foam be dense and springy memory foam would be the opposite of what is required e Insert the foam and check from the side view that the keyboard ribbon is raised Figure 27 In Figure 27 we see that the old compressed foam raises the keyboard flex PCB about 30 degrees The new foam insert should raise the keyboard flex PCB at least 45 degrees Use the tab height B as a reference for the height of the key
102. tly to see if the heat stake will separate If you require too much twisting force then stop Shave off more of the heat stake and try again The intent is to leave enough heat stake to have the calculator actually snap firmly back together when the procedure is completed If you are successful then repeat the exercise to the lower four heat stakes on the keyboard side of the calculator Figure 20 is a shot of the lower heat stakes after they have been drilled out Compare this to Figure 17 to see just how little drilling is required to separate the halves and yet retain the heat stake integrity for a reassembly Now that the heat stakes are prepared using the knife Fig 19 Prying the shells apart HP Solve 19 Page 30 Page 8 of 13 and starting at the battery housing gently pry the shells apart The heat stakes will snap apart a good sound as this indicates you left enough heat stake material to have the calculator snap back together Continue to work down the side of the calculator separating the halves as you go Figure 21 Fig 20 Heat stakes drilled When you have separated both halves from the top and the sides insert the knife at the bottom A gentle twisting force should allow the four remaining heat stakes to snap apart You will be left with two shells the top containing the logic PCB and problematic connection Figure 22 and the bottom shell containing the shielding and piezo transducer Figure 23 Fig 21
103. tor 19 converted to a decimal http en wikipedia org wiki Decimal expansion 1 the result has the same s1x digit http en wikipedia org wiki Numerical_digit repeating sequence after the decimal point but the sequence can start with any of those six digits For example 1 7 0 142 857 142 and 2 7 0 285 714 285 7 A seven sided shape is a heptagon http en wikipedia org wiki Heptagon The regular n gons for n lt 6 can be constructed by compass and straightedge http en wikipedia org wiki Compass and straightedge alone but the regular heptagon cannot Figurate numbers http en wikipedia org wiki Figurate_ number represent ing heptagons including seven are called heptagonal numbers http en wikipedia org wiki Heptagonal_number Seven is also a centered hexagonal number http en wikipedia org wiki Centered hexagonal number 8 There are seven frieze groups http en wikipedia org wiki Frieze_group the groups http en wikipedia org wiki Group_ 28mathematics 29 Consisting of symmetries http en wikipedia org wiki Symmetry group Of the plane whose group of translations http en wikipedia org wiki Translation_ 28mathematics 29 18 1soMOrphic http en wikipedia org wiki Isomorphic to the group of integers http en wikipedia org wiki Integer 9 There are seven fundamental types of catastrophes hittp en wikipedia org wiki Catastrophe theory 10 Seven is the sum of any two opposite sides on a standard s
104. torial prime a lucky prime htt en wikipedia org wiki Luc rime a happy number http en wikipedia org wiki Happy number a Safe prime http en wikipedia org wiki Safe_prime and the fourth Heegner number http en wikipedia org wiki Heegner number 2 Seven is the lowest number which cannot be represented as the sum of the squares of three integers 3 Seven is the aliquot sum http en wikipedia org wiki Aliquot_sum Definition Of one number the cubic num ber http en wikipedia org wiki Cubic number 8 http en wikipedia org wiki 8_ 28number 29 and 1s the base of the 7 aliquot tree 4 n 71s the first natural number for which the next statement does not hold Two nilpotent http en wikipedia org wiki Nilpotent endomorphisms nhttp en wikipedia org wiki Endomorphism from C with the same minimal polynomial http en wikipedia org wiki Minimal_polynomial and the same rank are similar 5 71s the only dimension besides the familiar 3 in which a vector cross product http en wikipedia org wiki Cross product Can be defined http en wikipedia org wiki Seven dimensional cross product 6 999 999 hitp en wikipedia org wiki 999999_ 28number 29 divided by 7 is exactly 142 857 http en wikipedia org wiki 142857_ 28number 29 Therefore when a vulgar fraction http en wikipedia org wiki Vulgar fraction Vulgar 2C_proper 2C_and_improper fractions with 7 in the denominator http en wikipedia org wiki Denomina
105. trigonometry functions that are on the keyboard You can visualize this by looking at the HP 30b keyboard Every key except the shift key itself has two functions the function printed on the top of the key and the blue function written on the front slope of the key Each of these two locations can be assigned as the starting key for a program In addition you can define assignments of programs to the shift and hold key position as well In this example we will assign the inverse sine function to the shift hold key the inverse cosine function to the shift hold key and the inverse tangent to the shift hold key To access these functions you would press ggg and while holding it down press the corresponding number key k N ABS Trigonometry FDWN Hyperbolic DWN Probability DINE Absolute DWN LOG DWN DW Value INPUT DWN Binomial HP Solve 19 Page 5 Page 2 of 7 To automate this type of function found in a menu make a list of the exact keys pressed to access the function manually These key presses will be entered in the program To perform an inverse sine you would press m er J The final a final works just as well is necessary to have the HP 30b execute the function instead of just previewing the potential answer To enter this series of key presses into a program you would press the following keys Enters program mode and displays the last program previously viewed in the program catalog
106. used to locate the holes and show the sphere inside the fixture as shown 10 figure four Here is the problem What is the relationship of the space between the two lines needed to construct the triangles and the diameter of the sphere D in order to mark four equally spaced points on the sphere e g S f D This is the second problem in a series of real world practical problems offered as a challenge to HP Solve readers Send your solution to the editor and if your solution is judged as the most practical clear using minimal math and 11 needed a calculator it will be published in HP Solve The winning idea is to give a clear step by step explanation of the solution Is it obvious that the sphere is tangent to the surface of the triangular sides The published solution winner will be determined by the following The decision of the judge s is final The description and clarity of the solution The use of graphics if needed to make understanding the solution easier and clearer The use of minimal mathematics 1 e algebra instead of calculus The use of an HP Calculator if helpful BRWN 62 HP Solve 19 Page 54 Page 7 of 8 What Marty wanted was a relationship between S and D He remembered spending a lot of time doing the math and then finding that the relationship was very simple He is fairly sure that he remembered that relationship but he would like independent confirmation Figure three shows how the f
107. user restorer and member of the London chapter of the HPCC His background includes ten years of flying in Canada s North j and the last 22 years as an airline pilot A graduate of Simon Fraser University with a M Sc in Palynology he is currently writing a book entitled A Guide for the restoration of Hewlett Packard calculators Geoff s SY collection includes over sixty HP calculators ranging from the HP 35 to the HP 35s and all the families in between each one restored to working condition with museum restoration standards in mind He would like to thank his wife Janice for supporting his calculator hobby HP Solve 19 Page 35 Page 13 of 13 Today s HP 41 User Article Today s HP 41 User Peter Platzer Ed Note Peter Platzer read about the 30 year old HP 41 in HP Solve issue 16 and wrote to share his current 0 experience with this classic Gen3 HP calculator I have loved the HP41 ever since it was introduced We were huddling around our classmate Georg who was showing off his brand new HP 41C with card reader and 4 printer Compared to our puny TI 51 II 11 steps 9 PROTOCODER storage registers no alpha the 41C was a marvel of 000 technology The now famous HP Key click made it a haptic delight to use and its revolutionary I O ports promised unlimited powers to solve problems or simply have fun No question I wanted one Alas it was many years before
108. ven for the 12 digit The 12 digit calculator will perform its calculations to more digits than you see in the display The extra digits typically a total of 15 for a 12 digit machine and 13 for a ten digit machine are called guard digits Two questions should immediately come to mind 1 Should the guard digits be retained and used for additional calculations and 2 should the display show the number truncated simply cut off at the last digit or rounded The vast majority of HP calculators do not use the guard digits for the next calculation What you see in the display when the machine stops running is what you get This is not true of most other brands of cal culators A favorite test many students will make is to take the square root of a number ten times and then square the result ten times and compare the result with the input number The results will greatly vary and surprise you Let s use Y3 1 73205 08075 68877 as a test number Begin with the number 3 and take the square root ten times On most current HP machines and you will see 1 00107343828 Square this answer ten times and the display will show 3 00000000835 Is this answer wrong It should be 3 Is it possible to have a 12 digit calculator be accurate enough to produce 3 The answer is NO Accuracy describes how close the result calculated by a calculator is to the true value as opposed to how close the displayed result is The reason is beyond the level
109. w version Working with im age names only is less productive e g FOI No keyboard Another advantage is that the F numbers place the images in the proper order 6 Additive inverses in mathematics is the opposite A number b is the number that when added to b yields zero The additive inverse of N is denoted N For example the additive inverse of 13 is 13 because 13 13 0 and the additive inverse of 0 5 is 0 5 because 0 5 0 5 0 7 Infinity is not a place nor is it a number in the real number sense Many mathematics teachers will say that the lazy eight symbol represents an infinitely large value Most number line representations do not in clude the infinity symbol and I included it for emphasis The symbol in MS Word from the symbol table is not accurate because the mathematics symbol is symmetrical about the center QO VS OO 8 A million is 1 000 000 or 10 in the US and a billion is 1 000 000 000 or 10 9 Setting the display mode larger than 9 digits requires a special key sequence See your owner s manual for details Using an HP35s for example requires you to first press the decimal point key which puts a 1 into the display for 10 or 11 All other digits after pressing the decimal point and 1 is displayed are ignored 10 One well known and respected expert on numerical computation accuracy is William Morton Kahan of the University of California Berkeley Check
110. wn accuracy Don t confuse the number of accurate digits with the number of resolution or precision digits You may measure the voltage of a battery to five digits but the accuracy of the measurement may only be good to three digits The added digits of resolution are useful for trends and comparisons but not useful for truth accuracy The number of significant digits is the number of accurate digits You simply round the number of all the other numbers to the number of significant digits What are significant digits Here is one explanation from http www physics uoguelph ca tutorials sig_fig SIG dig htm Non zero digits are always significant Thus 22 has two significant digits and 22 3 has three significant digits With zeroes the situation 1s more complicated Zeroes placed before other digits are not significant 0 046 has two significant digits Zeroes placed between other digits are always significant 4009 kg has four significant digits Zeroes placed after other digits but behind a decimal point are significant 7 90 has three significant digits Zeroes at the end of a number are significant only if they are behind a decimal point as in c Otherwise it is impossible to tell if they are significant For example in the number 8200 it is not clear if the zeroes are significant or not The number of signifi cant digits in 8200 is at least two but could be three or four To avoid uncertainty use scientific notation to
111. y Classroom Previous Article Next gt June 3 2010 naan na TEE ES Somat EBE EA Onm ne D Pa Tam With other calculators I ve tried I ve had to take a few minutes out of every class period to teach the students how to use the calculator on that day s lesson With the HP calculator the students just grab their calculators and 00 So Learning Has Changed Kids learn differently today so our technology and teaching methods must adapt HP designed the affordable easy to use 39gs Graphing Calculator and free calculator projection software shown above to enable math teachers to spend more time teaching and less time showing students how to use their calculators We also provide learning activities and teacher training so that our calculators can seamlessly integrate into math curriculum The 21st Century classroom needs more than just technology so we offer low cost tools training and integrated curriculum Follow this link to see the story of a math teacher in San Antonio who introduced HP calculators into his classroom and was amazed with the results Learn More To learn more about how HP can provide easy to use tools and training for your math teachers please contact emailreply hp com HP provides educators with complimentary software versions of our calculators Send your request to emulators hp com Products may qualify for use of Title Funds Have it all HP
112. y also be used as a length measurement caliper check as well See http www usmint gov about_the_mint action coin_ specifications 2 in the HP Solve Math Problem Challenge series HP Solve Math Problem Challenge 2 A Simple Geometry Problem In 1963 Marty worked for an 011 company research center as an IBM 1401 computer operator which was used as an input for an IBM 7094 computer All of the computer center users were researchers and most had PhDs At that time was he was building molecular models and studying transistors He wanted to build a model of silicon with a bond angle of 109 degrees and he needed a method to locate four equally spaced points on the surface of a sphere of a given diameter 12 Marty could not afford commercially sold model building kits because they were so expensive and he wanted to make a really large model for teaching purposes He could find a source of low cost wood spheres so the primary issue was determining the four points to drill the holes Fig 1 Two inch Styrofoam sphere with four Figure one shows a two inch Styrofoam sphere with four wood sticks inserted equally spaced 109 wood food skewers inserted at equally spaced points on the surface of the sphere The problem is being able to design and construct a fixture or jig to hold the sphere and provide the four points to mark on the surface A means to do this immediately came to mind but the calculations required for the dimensio

HP Solve: Issue 19 (June 2010)

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