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OEM OPERATING AND SERVICE MANUAL TM-100-1

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1. TE 22212 ae TIME SCALE 50 USEC PER DIVISION Figure 2 8 Index To Data Pulse 2 8 2 3 1 9 For double sided disk drives if Head 00 the lower head meets the specification check Head 01 the upper head NOTE Head 01 should meet the same specification 2 3 1 10 If either Head 00 or Head 01 does not meet the specification adjust the index sensor see Section 2 3 2 1 2 3 1 11 Recheck both indexes after they are adjusted 2 3 1 12 When both index measurements a double sided disk drive or the one index measurement on a single sided disk drive meet the specification check the index on Track 34 2 3 1 13 a double sided disk drive check Heads 01 and 00 the upper and lower heads NOTES If any index measurement does not meet the specification the index sensor must be adjusted see Section 2 3 2 1 If the index measurements meet the specification the index sensor does not need to be adjusted 2 3 1 14 Recheck all indexes after each adjustment 2 3 2 Index Adjustment 2 3 2 1 From the bottom of the chassis lossen the index sensor s retaining screw counterclockwise one quarter 1 4 turn see Figure 2 9 with a Phillips screwdriver 2 3 2 2 Adjust the index sensor with a flat blade screwdriver until the data pulse begins 200 usec 100 usec from t
2. SECTION Ill PRINTED CIRCUIT BOARD OPERATION 3 1 LOGIC POBA m Tcr 3 2 Interface COMNQUIALION vs ood qo s esce aoe x IER EN Ede E eed 3 3 Select Lines Schematic Diagram 3 4 Drive Motor Enable Schematic Diagram 3 5 Direction and Step Lines Schematic Diagram 3 6 Write Data Circuit Block Diagram 3 7 Write Data Schematic Diagram 3 8 Side Select Schematic Diagram 3 9 Index Schematic Diagram 3 10 Waveform at Test Point 7 Soft Sectored 3 11 Track 00 Schematic Diagram 3 12 Write Protect Schematic Diagram 3 13 Read Data Schematic Diagram 3 14 Read Circuit Block Diagram 2 52499 zs uU re ioe e acm ROLE d io 3 15 Servo PCBA oct ORE S BS dot ee 3 16 Servo Board Schematic Diagram Page Number LIST OF ILLUSTRATIONS FIGURES Figure Page Number Title of Figure i Number SECTION V REPLACEMENT PROCEDURES 5 1 Drive Belt and Pulleys ove RE ERE ERA RE seat 5 2 5 2 Logic PCBA
3. apa treme 1 4 9 Interface Connections oera eorr voa eed eb le SERE RU EA PERRA 1 4 10 Chassis Ground Dre ados Me Ra Aon Dem RARE REX RU BER Sa 1 4 10 1 Isolated Grounds c 25 0 e qua E acetate Omen eas sa Sat een b hare aet S es 1 5 11 Mounting The Disk Drive cecus e I RE eR RR RC 1 5 11 1 Hardware M aah SOA a edo at i eg dns 1 5 11 2 Dust COVE 22222025 ore voe DELE d esc adesse eire Ras 1 6 11 3 Cooling System Requirements 1 6 12 Diskette Care Handling and Storage 1 6 13 DAN EVENIET RAE Mu s ee iav E s 1 6 14 Operation of Ine DISK Drive MEE uS 1 6 15 Organization of The Disk Drive 1 7 16 Components of The Disk Drive 1 7 16 1 INGO PUSS REC PDT P 1 7 1 16 2 eaves eck cs deem ea Del nd a REX AC 1 7 1 16 3 Track 00 qux cies sd eiut aa ean wage tek ar ROG CE ACA Nae ard ei UNI SUN I os 1 7 1 16 4 Spindle Dnve System oos seat ve ER e A DS Pu mas 1 7 1 16 5 Positioner Control AE a eb v acre V CORE ded 1 8 1 16 6 Electronics
4. 5 23 5 20 Track 00 Switch Assembly Cable Harnessing 5 24 5 21 Track 00 Switch Assembly E Rings and Adjustment Screw 5 25 5 22 Track 00 Switch Assembly Mounting Screw 5 25 5 23 Write Protect Switch Assembly Arm and Adjustment Screw 5 27 5 24 Write Protect Switch Assembly Mounting Screw and Connector 5 28 5 25 Write Protect Switch Assembly Cable Harnessing 5 28 5 26 Nuts for Upper Arm and Spring 5 30 5 27 Upper Arm Assembly Parts Coin eo a E AM KM vC 5 31 5 28 Felt Pad on UpperArm pu efi 5 31 5 29 Module Assembly Parts cur EE tino tad ASTA 5 32 5 30 Spindle Assembly Mounting Screw Washer and Pulley 5 34 5 31 Spindle Assembly Retainer Hex Head Screws 5 35 5 32 Latch Plate Assembly Mounting Screws and Latch Inhibitor 5 37 TABLES Table Page Number Title of Table Number SECTION INTRODUCTION TO THE TM 100 1 AND 2 DISK DRIVES 1 1 Mechanical and Electrical Specifications 1 3 1 2 Interface Connector Pin Assignments J1 P1 1 12 1 3 Power Connector Pin
5. 4 d NOTES 1 0 250 MILLISECONDS AFTER DRIVE MOTOR 2 UNSYNCHRONIZED STARTS OR 20 MILLISECONDS AFTER LAST STEP PULSE WHICHEVER IS THE LATEST TIME 3 8 5 MA PEAK TO PEAK 4 4 u SECONDS MINIMUM 8 u SECONDS MAXIMUM Figure 1 4 Write Operation Timing Diagram The duration of a write operation is from the true going edge of Write Enable to the false going edge of Trim Erase This is indicated by the internal Write Busy waveform shown see Figure 1 4 The Read electronics consist of 1 ReadSwitch Side Select 2 Read Amplifier 3 Filter 4 Differentiator 5 Comparator and Digitizer The Read switch is used to isolate the Read Amplifier from the voltage excursion across the magnetic head dur ing a Write operation The side select is used to enable one of the Read Write Erase heads The disk drive must be in a ready condition before reading can begin As with the data recording operation this ready condition must be established by the user system In addition to the requirements established in this sec tion a 100 usec delay must exist from the trailing edge of the Trim Erase signal to allow the Read Amplifier to set tle after the transient caused by the Read switch returning to the Read mode The output signal from the Read Write head is amplified by a Read Amplifier and filtered by a linear phase filter to remove noise see Figure 1 5 The linear output from the filter i
6. OPERATING AND SERVICE MANUAL TM 100 1 AND 2 DISK DRIVES 48 TRACKS PER INCH 1 cd CORPORATION 20320 PRAIRIE STREET CHATSWORTH CA 91311 TELEPHONE 213 993 6644 TWX 910 493 5965 COPYRIGHT 1981 TANDON CORPORATION The information contained in this document is the property of Tandon Corporation It may not be duplicated in full or part by any person without prior written approval The material in this document is provided for informational purposes and is subject to change by Tandon Corporation Section Page Number Title of Section Number SECTION I INTRODUCTION TO THE TM 100 1 AND 2 DISK DRIVES 48 ox oet se ace a ote x ad Ge IE eee we eae 1 1 Purpose of The Disk 1 1 2 Physical Description of The Disk Drive 1 1 3 Functional Description of The Disk 1 1 4 DISKEUOS cee V ey tego cis Cae he he ee oe 1 2 5 Mechanical and Electrical Specifications 1 2 6 Interface Circuit Specifications 1 2 7 Uncrating he DISK Drive 25525025 do Ua e 1 2 8 Physical Checkout of The Disk
7. WRITE TRANSMIT 5 lo oF 2 Ti H 150 D G N SIDE D ONE bp 5 2 E 4 gt M as N ERASE o4 1 D aO 6 WRITE ONS con 1138P PROTECT C 3 O D SWITCH 150 NO Ji e o4 1520 N INTER N WRITE GRTE 24 5 NAL WRITE Busy DRIVE SELECT 857 Figure 3 8 Side Select Schematic Diagram 3 12 3 3 2 Outputs 3 3 2 1 Index N INDEX SECTOR Functional Description The Index signal is provided once each revolution 200 msec nominal to indicate the beginning of a track to the controller The Index line remains in the true low state for the duration of the Index pulse The duration of an In dex pulse is nominally 4 0 msec The leading edge of an index pulse must always be used to ensure diskette interchangeability between disk drives With a standard soft sectored diskette installed Test Point 7 see Figure 3 9 and Figure 3 10 is a high going pulse nominally 4 5 msec in duration every 200 msec INDEX EMITTER N INDEX SECTOR DRIVE SELECT INDEX DETECTOR 3 9 Index Schematic Diagram 4 MSEC AVERAGE Figure 3 10 Waveform at Test Point 7 Soft Sectored Circuit Description The Index signal from the disk drive comes in on J4 Pin 15 The Index signal is derived from an infrared LED and a photo transistor detector When the index hole in the disk drive allows the
8. MOUNTING SCREW CABLE HARNESS Figure 5 4 Cone Lever Assembly Harnessing and Mounting 5 4 5 Unloop the two 2 head cables from the right rail in two 2 places 5 4 6 At the rear of the Cone Lever Assembly cut the two 2 cable harnesses that hold the stepper motor cables in place see Figure 5 5 5 4 7 With a Phillips screwdriver remove the two 2 mounting screws that attach the Cone Lever Assembly to the chassis 5 4 8 Gently slide the head carriage to the front of the disk drive i e the Track 39 position 5 6 UPPER ARM FINGER STEPPER MOTOR CABLES MOUNTING SCREW ABLE HARNESSES 2 MOUNTING SCREW Figure 5 5 Cone Lever Assembly Harnessing Mounting and Stepper Motor Cables 5 4 9 Slide the Cone Lever Assembly rearward to release the upper arm finger see Figure 5 5 5 4 10 Remove the Cone Lever Assembly by lifting it up and toward the rear of the disk drive and sliding the front door out of its tracks 5 4 11 Holding the new Cone Lever Assembly put the front door into its tracks and move it as far as it will go toward the front of the disk drive Then carefully lower the cone lever lifting the upper arm finger over the cone lever 5 4 12 With a Phillips screwdriver install but do not tighten the two 2 mounting screws that attach the rear of the Cone Lever Assembly to the chassis 5 4 13 Reloop the two 2 head cables over the right rail in two 2 places 5 4 14 Using a Phil
9. 52 50 F 125 F 1 13 WRITE PROTECT The disk drive is equipped with a Write Protect Switch Assembly This sensor operates in conjunction with a dis kette that has a slot cut in the protective jacket When the slot is covered with a self adhesive tab the diskette is write protected The slot must be uncovered to write on the diskette 1 14 OPERATION OF THE DISK DRIVE The disk drive consists of the mechanical and electrical components necessary to record and to read digital data on a diskette User provided DC power at 12 V and 5 V is required for operation of the disk drive 1 15 ORGANIZATION OF THE DISK DRIVE All electrical subassemblies in the disk drive are constructed with leads that terminate in 4 to 5 pin connectors enabling the individual assemblies to be removed The magnetic heads are connected to the PCBA via cables that terminate in 5 pin female connectors and their associated male sockets which are located in close proximity to the Read Write data electronics Interface signals and power are rovided via connectors at the rear of the disk drive 1 16 COMPONENTS OF THE DISK DRIVE The disk drive consists of seven 7 functional groups 1 Index Pulse Shaper Write Protect Sensor Track 00 Sensor Spindle Drive Control Carriage Position Control gt wo Write Erase Control 7 Read Amplifier and Digitizer Figure 1 2 is a functional block diagram of the disk drive It should be ref
10. 5 11 16 To verify the Track 00 Switch Assembly s operation check it with an ohmeter see Section 2 2 3 NOTE 1 There should be an open connection between Pins 1 and 4 of Plug 11 and a connection between Pins 2 and 4 at Track 2 When the disk drive goes to Track 1 this reading should be reversed NOTE 2 There is no Track 00 output to the controller until the drive motor phase is correct see Section 3 3 2 2 5 26 5 12 WRITE PROTECT SWITCH ASSEMBLY 5 12 1 Visually ensure that the arm on the Write Protect Switch Assembly moves the switch and makes a clicking noise when the arm is pushed down see Figure 5 23 ERROR WRITE PROTECT ARM A ADJUSTMENT SCREW WRITE PROTECT SWITCH ASSEMBLY Figure 5 23 Write Protect Switch Assembly Arm and Adjustment Screw 5 12 2 Remove the Logic PCBA see Section 5 2 5 12 3 With a Phillips screwdriver remove the mounting screw that attaches the Write Protect Switch Assem bly to the side of the chassis see Figure 5 24 5 12 4 Cutthe harness that attaches the Write Protect Switch Assembly cables and the Activity LED Assem bly cables to the bottom of the chassis see Figure 5 25 5 12 5 Cut the harness that attaches the Write Protect Switch Assembly and the Activity LED Assembly cables to the bundle of wires that go to the PCBA see Figure 5 25 5 12 6 Remove the Write Protect Switch Assembly from the disk drive 5 12 7 Place the new Write Protect Switch Assemb
11. Frontpanel LED inoperative No Track 00 switch indication POSSIBLE CAUSE Interface incorrect Alignment off Defective read electronics Defective heads Interface not enabled LED not connected LED defective LED driver defective Defective seek Track 00 switch not connected Defective logic Defective Track 00 Switch RECOMMENDED ACTION Verify select is true and write enable is false Verify C E lobes index burst and Track 00 switch adjustment Replace Logic PCBA Replace Module Assembly Verify interface select and jumper configuration Check P9 Replace Front Panel LED Assembly Replace Logic PCBA See Section 4 2 Check P11 Replace Logic PCBA Replace Track 00 Switch Assembly SECTION V REPLACEMENT PROCEDURES 5 INTRODUCTION This section contains the replacement procedures for the TM 100 1 and 2 disk drives parts and assemblies 1 Drive Belt 2 Logic PCBA 3 Servo PCBA 4 Cone Lever Assembly 5 6 Activity LED Assembly 7 Front Panel 8 Guide Rail 9 Index Assembly 10 Drive Motor Assembly 11 Track 00 Switch Assembly 12 Write Protect Switch Assembly 13 Upper Arm Assembly 14 Module Assembly 15 Spindle Assembly 16 Latch Plate Assembly 5 1 DRIVE BELT 5 1 1 Remove the old drive belt from the pulleys see Figure 5 1 SMALL PULLEY Figure 5 1 Drive Belt and Pulleys 5 1 2 Taking care not to stretch the new drive
12. J1 INTERFACE CONNECTION PROTECT SWITCH PANEL LED INDEX TRACK 00 WRITE Figure 1 6 Logic Printed Circuit Board Assembly 1 13 1 18 2 Drive Select As shipped from the factory the disk drive is configured to operate in a single drive system The user can easily modify it to operate with other drives in a multiplexed multiple drive system The user can activate the multiplex option by cutting the MX position of the programmable shunt located at IC location 1E which allows the input output 1 lines to be multiplexed The Select lines provide a means of selecting and deselecting a disk drive These four 4 lines NDSO through NDS3 select one of the four 4 disk drives attached to the controller When the signal logic level is true low the disk drive electronics are activated and the disk drive is conditioned to respond to Step or to Read Write commands When the signal logic level is false high the Input Control lines and the Output Status lines are disabled A Select line must remain stable in the true low state until the execution of a Step or Read Write command is completed The disk drive address is determined by a Select Shunt on the PCBA Select lines zero through three 0 3 pro vide a means of daisy chaining a maximum of four 4 disk drives to a controller Only one 1 line can be true low at atime An undefined operation might result if two or more units are assigned the same address or if
13. Remove the E ring that holds the cone shaft on NOTE The cone s parts are now loose from the cone lever 4 LEVER SHOULDER WASHER d lt 6 CONE SPRING STEP WASHER gt 5 1 C BEARING Figure 5 8 Cone s Component Parts 5 10 5 5 4 5 5 5 Put the cone shaft through the cone Slip on the release spring the expander the upper bearing the step washer the cone spring and the spring washer 5 5 6 5 5 7 5 8 5 5 8 5 5 9 5 5 10 NOTE Ensure that the bearing is fully seated in the expander Compress the spring and put the cone shaft through the hole in the Cone Lever Assembly Install the three 3 washers and the E ring in order to retain the Cone Lever Assembly see Figure Reinstall the Cone Lever Assembly see Section 5 4 12 Make the required checks see Section 5 4 21 Reinstall the Logic PCBA see Section 5 2 5 6 ACTIVITY LIGHT EMITTING DIODE LED ASSEMBLY 5 6 1 Remove the Logic PCBA see Section 5 2 5 6 2 Cut the two 2 cable harnesses that attach the Activity LED Assembly and the Write Protect Switch Assembly to the chassis in front of the drive motor and to the bundle of wires in back of the drive motor see Figure 5 9 CABLE HARNESSES 2 Figure 5 9 Activity LED Assembly Cable Harnessing 5 6 3 Remove the retaining collar that holds the Activity LED Assembly cables to the LED grommet by tak ing a pair of needle nose pliers
14. STEP Functional Description When the disk drive is selected a true low pulse with a time duration greater than 200 nsec on the Step line initiates the access motion The direction of motion is determined by the logic state of the Direction line when a Step pulse is issued The motion is toward the center of the disk drive if the Direction line is in the true low state when a Step pulse is issued The direction of motion is away from the center of the disk drive if the Direction line is in the false high state when a Step pulse is issued To ensure proper positioning the direction line should be stable 100 usec minimum before the trailing edge of the corresponding Step pulse The Direction line should re main stable until 100 usec after the trailing edge of the Step pulse The access motion is initiated on the trailing edge of the Step pulse Test Point 8 see Figure 3 5 is low true when the carriage is positioned at Track 00 and the step motor is at Phase O When stepping in or out Test Point 12 see Figure 3 5 is a high going pulse for each step of the carriage see Table 3 4 TABLE 3 4 STEPPER LOGIC TRUTH Step in Toward Track 00 Step Out Toward Track 40 Circuit Description The direction line comes in on Pin 18 of the interface connector A high signal directs the step logic to step in to ward Track OO A low signal directs the stop logic to step out toward Track 39 The direction line sets the proper phase
15. n l rg 5V ci 270 PFb 2 R65 INJO 750 NINT 5 E WRT BUSY 5 SIDE SELECT 5 AND READ WRITE Figure 3 13 Read Data Schematic Diagram 3 16 The Read signal is presented to IC 5D which is another edge detector and then goes to IC where the pulses are shaped to 1 usec This output is gated at IC 1F with the Unit Select signal to produce a digital output at Pin 30 of the interface connector see Figure 3 14 NOTE IC 5E the final one shot is enabled only when the disk drive is in a Read state Pin 11 TEST POINT 1 UPPER HEAD READ AND HEAD SIGNAL AMPLIFIER TEST POINT 2 IC 3A SWITCHING CIRCUITS HEAD TEST POINT 3 COMPARATOR IC 58 5C 5D CROSSOVER DETECTOR 5B DIFFERENTIATOR IC 4A TEST POINT 4 DATA OUTPUT IC 5D 5E UNIT SELECT Figure 3 14 Read Circuit Block Diagram 3 17 3 4 PHYSICAL DESCRIPTION OF THE SERVO The Servo PCBA is approximately 127 mm 5 0 inches long by 38 mm 1 5 inches wide Figure 3 15 illustrates the placement of test points and connectors J1 SERVO JUMPER DRIVE MOTOR SPINDLE SPEED CONTROL Figure 3 15 Servo PCBA 3 4 1 Input Control Lines Functional Description When the logic board receives a true low Motor On signal a true low signal is sent to the servo board N MO TOR ON see Figure 3 16 This signal turns on the regulator Q1 and the motor s s
16. NO PORTION OF THIS 576 DATA SHALL BE RELEASED DISCLOSED USED 2 ALL CAPS ARE IN uFD OR DUPLICATED FOR USE IN PROCUREMENT OR LOGIC SCHEMATIC 3 ALL DIODES ARE IN 4446 MANUFACTURING WITHOUT SPECIFIC WRITTEN 4 ALL TRANSISTORS NPN ARE 2n4124 amp PERMISSION FROM TANDON PNP ARE 2N4125 l 1 00000 IF 80000 28 ETE e tu p j c39 00600600 5 000000 THE INFORMATION CONTAINED HEREIN IS THE PROPERTY OF TANDON NO PORTION OF THIS DATA SHALL BE RELEASED DISCLOSED USED OR DUPLICATED FOR USE IN PROCUREMENT OR MANUFACTURING WITHOUT SPECIFIC WRITTEN PERMISSION FROM TANDON NOTES UNLESS OTHERWISE SPECIFIED 1 COMPONENT HEIGHT NOT TO EXCEED 35 ABOVE P C BOARD LOGIC PCBA ASSEMBLY DRAWING t i P20 PART OF P2 12V 3 3 MOTOR POWER GND 412 MOTOR RETURN ce R4 IK POT 1 7 4 TacH 1412 AN MOTOR ON 4TACH 5 Re Er ICE PART OF P20 NOTES UNLESS OTHERWISE SPECIFIED 1 RESISTORS ARE IN OHMS 5 1 4 W 2 1 RESISTORS ARE 1 8 W SERVO PCBA 3 CAPACITORS ARE IN uF 20 35 V LINEAR 6 1 NOTES UNLESS OTHERWISE SPECIFIED 1 ASSEMBLE PER STANDARD MANU FACTURING METHODS 2 THIS ASSEMBLY SHALL BE MADE FROM PCB DETAIL 178901 001 REVI SION A el 21 THE INFORMATION CONTAINED HEREIN IS THE PROPERTY OF TANDON NO PORTION OF THIS DATA SHALL BE RELEASED DISCLOSED USED OR DUPLICATED FOR USE IN PROCUREMENT OR MANUFACTURING WITHO
17. Assignments 1 13 LIST OF ILLUSTRATIONS TABLES Table Page Number Title of Table Number SECTION Ill PRINTED CIRCUIT BOARD OPERATION 3 1 Symbols and Abbreviations 3 2 3 2 Interface Connector Pin Assignments J1 P1 3 4 3 3 Power Connector Pin Assignments dE Ede aC EAE LA 3 5 3 4 Steppe Logic oed ea n E Lord ORA ae D 3 7 vi SECTION I INTRODUCTION TO THE TM 100 1 AND 2 DISK DRIVES 48 TPI 1 INTRODUCTION This section contains a description of the physical and functional specifications for the TM 100 1 and 2 disk drives 48 tracks per inch TPI manufactured by Tandon Corporation 1 1 PURPOSE OF THE DISK DRIVE The disk drive is a mini disk memory designed for random access data entry storage and retrieval applications These applications typically are intelligent terminal controllers microcomputers word processing systems data communications systems error logging microprogram loading and point of sale terminals The disk drive is capable of recording and reading digital data using FM MFM M2FM or GCR techniques 1 2 PHYSICAL DESCRIPTION OF THE DISK DRIVE The disk drive can be mounted in any vertical or horizontal plane However when mounted horizontally the logic circuit board must be up The spindle is belt driven by a DC motor with an
18. WRITE ENABLE 3 9 3 3 1 5 Write Data N WRITE DATA 3 9 3 3 1 6 Side Select N SIDE SELECT 55544554 eens 3 10 3 3 2 hun Mes I a Sin 3 13 3 3 2 1 Index N JINDEX GECTOR s ezes ses Saws EAR TX TIE ERA ERAS COR ees 3 13 3 3 2 2 Tracko0 nonni eos es HUE EX hes ee Aem EE icut e crear 3 14 3 3 2 3 Write Protect N WRITE PROTECT 3 14 3 3 2 4 Read Data N READ DATA 3 15 3 4 Physical Description of The Servo PCBA 3 18 3 4 1 input Control Unes Ra RC e oue eee 3 18 SECTION IV TROUBLESHOOTING GUIDE 4 IntFOdUGCBon 2 4 vet vet ACER Cx wee xx o mE 4 1 4 1 Not Ready and or 4 2 4 2 Wil Not Seek or Restore 22225557 ek E a E IURE 4 2 4 3 WHLNOE WING oue sta v oe ox e wa E ROSE 4 2 4 4 WIIENOPHOSG oa ves ev OC coa os oe vh agendo dpa ue 4 3 4 5 Front Pane LED InoperatiV8 we RES xe TE E eR 4 3 4 6 No Track Indication FG eA Y Y SEE eee APRES YE EA 4 3 SECTION V REPLACEMENT PROCEDURES 5 Introductio TC L
19. WRITE ENABLE Functional Description When the Write Enable signal is true low the write electronics are prepared for writing data read electronics disabled This signal turns on the write current in the read write head Data is written under control of the Write Data input line It is generally recommended that changes of state on the Write Enable line occur before the first Write Data pulse However the separation between the leading edge of Write Enable and the first significant Write Data pulse should not be less than four 4 usec and not greater than eight 8 usec The same restrictions exist for the relationship between the least significant Write Data pulse and the termination of the Write Enable signal When the Write Enable line is false high all write electronics are disabled When a write protected diskette is installed in the disk drive the write electronics are disabled irrespective of the state of the Write Enable line Stepping is also disabled by a true low Write Enable see Section 3 3 1 3 Tandon Corporation recommends that the controller wait one 1 msec after the N WRITE ENABLE goes false before any step pulses are sent to the disk drive Circuit Description The Write Gate signal comes in on Pin 24 of the interface connector It is buffered through IC 3D and gated at IC 3B by the Write Protect and the Unit Select signals becoming the N WRITE signal The N WRITE signal goes to Pin 9 of IC 3C which is configure
20. Write Data TABLE 1 2 INTERFACE CONNECTOR PIN ASSIGNMENTS J1 P1 CONTROLLER TO DISK DRIVE Connector Clamp Spare Select 3 053 SelectO NDSO Select 1 051 Select2 052 Drive Motor Enable N MOTOR ON Direction Step NSTEP Write Data N WRITE DATA Write Gate N WRITE ENABLE Side Select N SIDE SELECT Connector Clamp DISK DRIVE TO CONTROLLER Index NINDEX SECTOR Track 00 N TRK 00 Write Protect N WRITE PROTECT ReadData NREADDATA TABLE 1 3 POWER CONNECTOR PIN ASSIGNMENTS 12VDC Return 12 VDC Return 5 VDC 5 VDC 5 Side Select 6 Write Gate These input lines are terminated through a 150 ohm resistor pack that is installed in the dip socket located at IC location 2F In a single drive system this resistor pack should be kept in place to provide the proper terminations in a multiple drive system Program Shunt position MX open only the last drive on the interface is to be termina ted All other drives on the interface must have the resistor pack removed see Figure 1 6 UPPER HEAD LOWER HEAD 13 READ WRITE HEAD 5 P6 TP TPS PROGRAMMABLE HUNT SOCKET 1 STEPPER MOTOR TPO RVO JUMPER CA e TP6 e PB P9 P100 P2 42 J4 POWER TERMINATOR SOCKET 2F r x UNUSED 1 O INTERFACE CONNECTIONS
21. and remeasure the ISV see Sec tion 2 1 2 If replacing the drive belt and the drive motor does not cure the excessive ISV see Section IV Troubleshooting Guide CATS EYE ALIGNMENT CHECK AND ADJUSTMENT The Cats Eye CE alignment procedure locates the magnetic read write head at the proper radial distance from the hub center line thus ensuring that the track location is accurate see Figure 2 4 This adjustment is neces sary only after service or if diskette interchange problems are suspected 2 2 1 2 2 1 1 CE Alignment Check Set up a dual channel wideband oscilloscope as follows Channel Test Point 1 Channel B Test Point 2 Ground Test Point 10 Read Differentially A plus B B inverted Time Base 20 msec Per Division External Trigger Test Point 7 Positive Edge 2 3 2 2 1 2 2 2 1 3 2 2 1 4 2 2 1 5 2 2 1 6 2 2 1 7 2 2 1 8 Apply power to the disk drive HUB CENTER LINE TRACK 1 1 125 0005 TRACK 16 TRACK 35 Figure 2 4 Hub Center Line and Track Locations NOTES The Track 16 radius is 1 9167 Other track locations are computed based upon 48 Select the disk drive with the interface logic Insert a Cats Eye alignment diskette Dysan alignment diskette number 800180 into the disk drive Select Head 00 the lower head Read Track 16 for Cats Eye alignment of the lower magnetic head Adjust the dual channel wideband oscilloscope to observe a Cats Eye pattern see Figu
22. driven through a drive belt by a DC motor tachometer combination The servo electronics required for speed control are associated with the spindle drive motor The control circuitry also includes a current limiter and interface control line When the Drive Motor Enable inter face line is true the drive motor is allowed to come up to speed When the current through the drive motor ex ceeds 1 3 ampere the current limit circuitry disables the motor drive D C STEPPER MOTOR BAND DRIVE AND HEAD ASSEMBLY WRITE PROTECT D C DRIVE INTERFACE CONTROL POSITIONER CONTROL WRITE BUSY WRITE ERASE M Mu ee er ANO WAVEFORM GENERATOR WRITE ENABLE SIDE SELECT READ DATA READ AMPLIFIER AND DIGITIZER Figure 1 2 TM 100 Disk Drive Functional Block Diagram 1 16 5 Positioner Control The Head Positioning system utilizes a four phase stepper motor drive which changes one phase for each track advancement of the Read Write carriage In addition to the logic necessary for motion control a gate is provided which inhibits positioner motion during a write operation 1 16 6 Data Electronics Information can be recorded on the diskette by using a double frequency code Figure 1 3 illustrates the magneti zation profiles in each bit cell for the number sequence shown for FM recording The erase gaps provide a guard band on either side of the recorded track This provides flex
23. for checks and adjustments 1 A dual channel wideband oscilloscope HP 1740A or equivalent 2 Anexerciser or software routine capable of stepping the disk drive to any track selecting the upper or lower head and writing a 1F all zeros if FM or a 2F all ones if FM pattern A Phillips screwdriver A 050 Allen wrench A flat blade screwdriver A 3 16 nut driver work diskette o N gt An alignment diskette Dysan P N 222 2 2 1 DRIVE MOTOR CHECKS AND ADJUSTMENTS The long term drive motor speed adjustment ensures that the motor s speed is within the range of toler ance specified The motor speed specification is 300 rpm 1 5 2 1 1 Long Term Drive Motor Speed Checks and Adjustment 2 1 1 1 Preliminary checks required Verify power 12VDC x 6V 5 VDC 25V 2 1 1 2 Apply power to the disk drive 2 1 1 3 Activate the drive motor on the interface line 2 1 1 4 Insert a work diskette 2 1 1 5 Observe the speed disk on the spindle pulley under flourescent lighting see Figure 2 1 2 1 1 6 Adjust R4 located on the Servo PCBA until the applicable pattern on the pulley appears sta tionary see Figure 2 2 2 1 1 7 2 1 2 OUTER BARS ON TIMING DISK TIMING RING USED FOR 60H FRONT INNER BARS ON TIMING DISK TIMING RING USED FOR 50H Figure 2 1 Bottom View of The TM 100 Disk Drive SERVO JUMPER DRIVE MOTOR SPINDLE SPEED CONTROL Figure 2 2 Location of R4 Speed Contr
24. level is false high the input control lines and output status lines are disabled 5V 5 ENTE RI R SHUNT 1E Pe Td Ji R43 2 mpsom lis IN 8 SELEC 10 5 DC pepe e 7 ey pd a ru SELecr 316 FA pied m 8 cC pec 45 64 212 E Figure 3 3 Select Lines Schematic Diagram A select line must remain stable in the true low state until the execution of a Step or Read Write command is completed The disk drive address is determined by a Select Shunt on the PCBA Select lines 0 3 provide a means of daisy chaining a maximum of four 4 disk drives to a controller Only one line can be true low at a time An undefined operation might result if two or more units are assigned the same address or if two or more select lines are in the true low state simultaneously 3 5 When the disk drive is selected the activity front panel LED will be In a multiple disk drive system the MX jumper must be cut If not the disk drive will always be active Circuit Description R14 holds the output of the appropriate select line high until the line is driven low This is buffered through IC 9 to 8 to IC 3D 9 to 8 IC 3D Pin8 is the output that enables the drive electronics Note that when the MX jumper is not cut the disk drive is always enabled Pin 3D 8 high The front panel LED is driven by the select logic through IC Pin to 4 Note that if the disk dr
25. light to turn on the detector Q8 is turned on sending a signal through IC 2E to IC 1F to be gated by the Drive Select signal to produce a low output at Pin 8 of the interface connector 3 3 2 2 Track 00 00 Functional Description When the disk drive is selected the Track 00 Interface signal indicates to the controller that the read write head is positioned at Track 00 The Track 00 signal remains true low until the head is moved away from Track 00 The Track 00 switch usually is deactivated between Track 1 and Track 2 Test Point 8 see Figure 3 11 istrue low when the carriage is positioned at Track 00 and the Step Motor phase is correct DRIVE SELECT 4C 8 and 4C 6 are high on Phase 0 only Figure 3 11 Track 00 Schematic Diagram Circuit Description The Track 00 switch is internal to the disk drive Its signal comes in on Connector 11 4F is alatch that debounces the switch noise The Track 00 switch is activated between Track 00 and Track 3 The combination of the Track 00 switch being activated and the proper stepping motor phase Phase 0 produces all high signals at IC 4B Pins 9 10 12 and 13 This signal subsequently is buffered through IC 3D Pin 1 and Pin 2 IC 1F Pins 11 12 and 13 gate the Track 00 output with the disk drive select output to give a Track 00 output to the controller at Pin 26 of the interface connector 3 3 23 Write Protect WRITE PROTECT Functional Description Whe
26. pulling it toward the front of the disk drive 5 11 7 Put the new Track 00 Switch Assembly into the disk drive near the left hand rear of the chassis 5 11 8 Push the new Track 00 Switch Assembly toward the rear of the disk drive until its mounting hole is aligned with the mounting hole in the chassis 5 24 E RINGS 2 NS E RINGS 2 MA R ADJUSTMENT SCREW Figure 5 21 Track 00 Switch Assembly E Rings and Adjustment Screw MOUNTING screw Figure 5 22 Track 00 Switch Assembly Mounting Screw 5 11 9 sure that there are no cables underneath the Track 00 Switch Assembly 5 11 10 With a Phillips screwdriver install and tighten the mounting screw that attaches the Track 00 Switch Assembly to the bottom of the chassis see Figure 5 22 5 11 11 Reinstall the E ring with an E ring insertion tool 5 11 12 Harness the new Track 00 Switch Assembly s cables the Activity LED Assembly s cables and the Write Protect Switch Assembly s cables to the bottom of the chassis see Figure 5 20 5 11 13 Harness the bundle of cables including the new Track 00 Switch Assembly s cables located at the back of the drive motor see Figure 5 20 5 11 14 Reinstall the Logic PCBA see Section 5 2 5 11 15 Toadjustthe Track 00 Switch Assembly loosen the mounting screw and move the switch in or out by turning the adjustment screw if the reading was previously incorrect see Section 2 2 3
27. return of the disk drive is connected to the drive chassis If a particular application does not require this the mounting screw near the middle of the servo may replaced with a nylon screw This isolates the power return from the chassis ground 1 11 MOUNTING THE DISK DRIVE The disk drive has been designed such that it can be mounted in any plane i e upright horizontal or vertical The only restriction is that the logic PCBA side of the chassis must be uppermost when the disk drive is mounted horizontally Eight 8 6 32 tapped holes are provided for mounting two 2 on each side and four 4 on the bot tom of the housing see Figure 1 1 86 HO P C B A SIDE MOUNTING HOLE BOTTOM MOUNTING HOLES 2 Sg BOTTOM VIEW SIDE MOU FOUR 4 MOUNTING HOLES Nove ON UNIT FARSIDE BOTTOM No 6 32 UNC 2B x 31 DP SIBEUIEN Figure 1 1 TM 100 Disk Drive Mounting Configuration 1 11 1 Hardware The disk drive is manufactured with certain cricital internal alignments that must be maintained Hence it is im portant that the mounting hardware does not introduce significant stress on the disk drive 1 5 Any mounting scheme in which the disk drive is part of the structural integrity of the enclosure may cause equip ment operating problems and should be avoided Mounting schemes should allow for adjustable brackets or incorporate resilient members to accommodate tolerances 1 11 2 Dust Cover T
28. to the exclusive OR gates of IC 5D This signal is also buffered by IC 3D to gate IC 4F to inhibit stepping inward when the disk drive is already at Track 00 This is done at Pin 4 of IC 4B The step pulses come in at Pin 20 of the interface connector They are buffered by 2E and gated at IC 4B by the unit select the Not Write signal and by the inward step inhibit at the Track 00 signal Then the step pulses go to the C inputs of the two 2 flip flops at IC 4C The direction of the step hence the selection of the flip flop to be toggled is done by the two 2 exclusive OR gates of IC 5D These gates are controlled by the step direction line and by the state of the two 2 flip flop outputs IC 3E Pins 5 and 6 resets the two 2 flip flops after a Power On The output of the two 2 flip flops drives the stepper motor throughthe drivers of IC 4D The diodes are for voltage spike elimination 3 7 9 TRACK OO SWITCH a 1520 6 4 UNIT SELECT 74 26 4 DIRECTION 31 7 25 N STEP BRN HEAD POSITION Figure 3 5 Direction and Step Lines Schematic Diagram 3 8 The disk drive is shipped with R50 in place and with R51 not in place If the resistor is moved to position R51 the power is only on to the stepper motor when the disk drive is selected 3 8 watts of power are saved because power is not applied to the stepper motor unless the disk drive is selected 3 3 1 4 Write Enable
29. 11 With a gram gauge carefully apply fifteen 15 grams pressure to the upper arm increasing the load force on the magnetic head Note Fifteen grams is about the weight of a quarter 2 4 1 12 If the output shown on the dual channel wideband oscilloscope increases by more than ten percent 1096 adjust the compliance 2 4 2 Compliance Adjustment The compliance is adjusted by using the same procedure as is used in the compliance check see Section 2 4 1 2 4 2 1 Turn the two 2 nuts that attach the upper arm to the carriage assembly see Figure 2 10 counter clockwise one quarter 1 4 turn with a 3 16 nut driver CARRIAGE ASSEMBLY Figure 2 10 Upper Arm and Nuts 2 4 8 2 While monitoring the output move the upper arm around the axis of the head until the output is the highest 2 4 2 3 the two 2 nuts that attach the upper arm to the carriage assembly clockwise with a 3 16 nut driver while holding the arm in the highest position 2424 HReverify the compliance of the magnetic head 2 4 2 5 If the compliance cannot be adjusted replace the upper arm see Section 5 13 2 5 WRITE PROTECT SWITCH ADJUSTMENT PROCEDURE 2 5 1 Connect the disk drive to an exercisor or computer with a direct monitor of write printed output Pin 28 of J1 or with no power to the disk drive disconnect Plug 8 and check the continuity with an ohmeter 2 5 2 With a non write protected diskette inserted verify that there is no continuity be
30. 2 EU Module Assembly Parts NOTE One screw is located on the top middle at the back of the chassis The other two screws are located underneath the middle of the chassis 5 14 4 Remove the Module Assembly from the chassis by lifting it up 5 14 5 Install the new Module Assembly by placing its left hand side against the module spring and by com pressing the module spring to seat the other side of the Module Assembly 5 32 5 14 6 With a Phillips screwdriver reinstall the three 3 mounting screws and their flat washers that attach the Module Assembly to the chassis see Figure 5 28 5 14 7 Install the Cone Lever Assembly see Section 5 4 5 14 8 Install the Logic PCBA see Section 5 2 5 14 9 Complete all the maintenance checks see Section Il 5 14 10 Make any necessary adjustments see Section II 5 33 5 15 SPINDLE ASSEMBLY 5 15 1 Remove the Logic PCBA see Section 5 2 5 15 2 Remove the Cone Lever Assembly see Section 5 4 5 15 3 Remove the drive belt see Section 5 1 5 15 4 Lay the disk drive on its side 5 15 5 With a Phillips screwdriver while holding the hub remove the mounting screw and washer from the Spindle Assembly see Figure 5 30 5 15 6 Remove the large pulley from the bottom of the chassis see Figure 5 30 MOUNTING SCREW FLAT WASHER LARGE PULLEY Figure 5 30 Spindle Assembly Mounting Screw Washer and Pulley 5 15 7 Using one quarter 1 4 i
31. BA 914000 001 Drive Belt 171011 001 Index Assembly 171011 002 Index Assembly II 171010 001 LED Assembly 172000 001 Cone Assembly one piece 172267 001 Cone Assembly two piece 172001 001 Latch Assembly 172025 001 Right Hand Guide Zinc 172026 001 Left Hand Guide Zinc 172230 001 Right Hand Guide Aluminum 172231 001 Left Hand Guide Aluminum 172027 001 Front Panel With Bushings 171046 001 Spindle Assembly 171003 001 Module Double Sided Recording Zinc 171003 002 Module Single Sided Recording Zinc 171113 001 Module Double Sided Recording Aluminum 171113 002 Module Single Sided Recording Aluminum 171103 001 Single Sided Recording Upper Arm 172266 001 Track 00 Stop 171002 001 Cone Lever Assembly NOTE All components are standard commercial parts purchased to original manufacturer s specifications OEM OPERATING AND SERVICE MANUAL TM 100 1 and 2 48 TPI ALIGNMENT DISKETTE Recommended Dysan P N 800180 111 1
32. Connectors and Mounting Screws 5 3 5 3 Servo PCBA Connectors Mounting Screws and Spacers 5 4 5 4 Cone Lever Assembly Harnessing and Mounting 5 6 5 5 Cone Lever Assembly Harnessing Mounting and Stepper Motor Cables 5 7 5 6 Cone Lever Assembly Cable 5 8 5 7 Cone Shaft and ooh pP NATUS UP PITT e ent bep wa E 5 9 5 8 Cone s COMPONENT Pans oer rade Y EROTIC dee RCRUM ddr e RES 5 10 5 9 Activity LED Assembly Cable Harnessing 5 12 5 10 Activity LED Assembly Retaining Collar and LED Grommet 5 13 5 11 Front Panel Bushings os ER RA AURA Ra fed ad o 5 14 5 12 Activity LED Assembly Retaining Collar and Grommet 5 15 5 13 Front Panel Mounting Screws 5 15 5 14 Front Panel Bushings and Locating Tabs 5 17 5 15 Index Emitter Sensor Harnessing and Mounting 5 19 5 16 Index Detector Sensor Mounting Screw and Cable 5 20 5 17 Index Emitter and Index Detector Sensor Cables and Bundle 5 20 5 18 Drive Motor Assembly Harnessing and Mounting 5 22 5 19 Drive Motor Assembly Pulley
33. ED 5 1 5 1 Drive dq PTT 5 2 TABLE OF CONTENTS TABLE OF CONTENTS Section Page Number Title of Section Number SECTION V REPLACEMENT PROCEDURES 5 2 Logic PCBA cs osx Rx eoa pou nw LR RA Ea LS PER 5 3 5 3 Seno POBA 455555 Qe IE den s inae dera qe i eu ue 5 4 5 4 Cone Lever Assembly o Lue ER Y ERO AR a EX da XC M e 5 6 5 5 CONG Kit on a hau RC Ue e Vcn or ecd m duc Ea AS boe 5 10 5 6 Activity LED Assembly arma ud pre eda E 5 12 5 7 Front Panel Drm 5 14 5 8 Guide Rail a EA A TTE 5 17 5 9 Index Beg debba dd die a e e rbv aetna 5 19 5 10 Drive Motor AsSembIy Ra OI WS ER 5 22 5 11 Track 00 Switch Assembly 2 22 ERA a PX ERI 5 24 5 12 Write Protect Switch Assembly 5 27 5 13 Upper Arm Assembly Single Sided Drives Only 5 30 5 14 Module Assembly osx REA UE VETE e ERN te 5 32 5 15 Spindle ASSSOIiDIV morire dec hore Ce RIPE er RE a Bie 5 34 5 16 tateh Plate ASSemoly ccs duy ae RR OE dO d E Mee Cow ERN O45 e 5 37 APPENDIX PCB SCHEMATICS AND ASSEMBLY DRAWINGS 1 1 APPENDIX Il TIMING REQUIREMENTS il 1 APP
34. ENDIX 1 MASTER SPARE PARTS LIST 11 1 LIST OF ILLUSTRATIONS FIGURES Figure Number Title of Figure SECTION I INTRODUCTION TO THE TM 100 1 AND 2 DISK DRIVES 48 1 1 TM 100 Disk Drive Mounting Configuration 1 2 TM 100 Disk Drive Functional Block Diagram 1 3 FM Recording Magnetization Profiles 1 4 Write Operation Timing Diagram 1 5 Read Timing Diagram rrr 1 6 Logic Printed Circuit Board Assembly SECTION Il MAINTENANCE CHECKS AND ADJUSTMENTS 2 1 Bottom View of The TM 100 Disk 2 2 Location of R4 Speed Control 2 3 ISV PulsePallein 2 HAS d ste ETE 2 4 Hub Center Line and Track Locations 2 5 Cals Eye Patte dae Ee Eod bak 2 6 Head Module Retaining and Cam Screws 2 7 Track 00 Stop sacre ERGO ES ARES ce Da one ated 2 8 Iridex to Data Pulse dese UR CS Uie 2 9 Index Sensor s Retaining Screw and Adjustment 2 10 Upper Arm anc NUls vua st x rax esu S SOLE QUERI EQUI SA deae heute 2 11 Write Protect Switch Adjustment
35. ISSION LINE 1 10 7416 EQUIVALENT Figure 3 2 Interface Configuration It is recommended that the interface cable be flat ribbon cable with a characteristic impedance of 100 ohms or equivalent twisted pairs i Interface connector pin assignments and power connector pin assignments are given in Table 3 2 and Table 3 3 3 3 4 Input Control Lines TABLE 3 2 INTERFACE CONNECTOR PIN ASSIGNMENTS J1 P1 CONTROLLER TO DISK DRIVE Connector Clamp Spare Select 3 NDS3 Select 0 NDSO Select 1 NDS1 Select 2 NDS2 Drive Motor Enable N MOTOR ON Direction DIR Step NSTEP Write Data NWRITE DATA Write Gate N WRITE ENABLE Side Select SIDE SELECT Connector Clamp DISK DRIVE TO CONTROLLER t Index N INDEX SECTOR Track 00 NTRK 00 Write Protect N WRITE PROTECT Read Data N READ DATA 3 4 TABLE 3 3 POWER CONNECTOR PIN ASSIGNMENTS 12VDC Return 12 VDC Return 5 VDC 5 VDC 3 3 1 1 Select Lines NDSO NDS3 Functional Description The select lines see Figure 3 3 provide a means of selecting and deselecting a disk drive These four 4 lines NDSO NDS3 standard select one 1 of the four 4 disk drives attached to the controller When the signal logic level is true low the disk drive electronics are activated and the disk drive is conditioned to respond to Step or Read Write commands When the logic
36. NUTS 2 Figure 5 26 Nuts for Upper Arm and Spring Retainer 5 13 4 Carefully lift off the spring retainer and spring see Figure 5 27 5 13 5 Remove the Upper Arm Assembly 5 13 6 Place the new Upper Arm Assembly on the two 2 set screws 5 13 7 Carefully replace the spring and spring retainer see Figure 5 27 5 13 8 Ensuring that the spring is seated on both ends reinstall but do not completely tighten the two 2 set screws that hold on the Upper Arm Assembly and the spring retainer 5 13 9 Visually align the felt pad on the arm with the head see Figure 5 28 5 13 10 Tighten the two 2 set screws see Figure 5 27 5 13 11 Insert a diskette into the disk drive 5 13 12 Visually check to ensure that the felt pad clears the disk drive when the front door is opened see Figure 5 28 5 30 SPRING RETAINER UPPER ARM ASSEMBLY SET SCREWS 2 Figure 5 27 Upper Arm Assembly Parts FELT PAD Figure 5 28 Felt Pad on Upper Arm 5 13 13 Reinstall the Logic PCBA see Section 5 2 5 13 14 Check the compliance see Section 2 4 5 13 15 Adjust the compliance if necessary see Section 2 4 2 5 31 5 14 MODULE ASSEMBLY 5 14 1 Remove the Logic PCBA see Section 5 2 5 14 2 Remove the Cone Lever Assembly see Section 5 4 5 14 3 With Phillips screwdriver remove the three 3 mounting screws and their flat washers that attach the Module Assembly to the chassis see Figure 5 29 MOUNTING FLAT WASHERS
37. UT SPECIFIC WRITTEN PERMISSION FROM TANDON SERVO PCBA LINEAR APPENDIX Il TIMING REQUIREMENTS POWER LJ 100 MS MIN MOTOR ON DRIVE SELECT VALID TRK 00 lt 500 ns MAX AND WRT PROT kai OUTPUT M MAX VALID INDEX 250 MSEC MA md SECTOR OUTPUT E lug 500 ns MAX DIRECTION SELECT Re Us MIN eres 1 Us MIN 1 Us MIN lm 5 MS MIN 20 MS MIN ani Us MAX 250 MSEC WRITE DATA VALID 20 MS MIN Lacon Us MIN READ DATA 250 MSEC M MODEL TM 100 GENERAL CONTROL AND DATA TIMING REQUIREMENTS MODEL TM 100 1 PRODUCT SPEC MINI SINGLE SIDED RECORDING FLEXIBLE DISK DRIVE 1 1 POWER J 100 MS MIN MOTOR ON MPH DRIVE SELECT VALID TRK 00 AND WRT PROT OUTPUT VALIO INDEX 250 MSEC MAX SECTOR OUTPUT 500 ns MAX DIRECTION SELECT Biel pe Us MIN STEP 1 Us MIN A 1 Us MIN Latin 5 MS MIN 20 MS MIN m Us MAX 2 M WRITE DATA o MoET VALID 20 MS MIN Los Us MIN 250 MSEC MODEL TM 100 GENERAL CONTROL AND DATA TIMING REQUIREMENTS MODEL TM 100 2 PRODUCT SPEC MINI DOUBLE SIDED RECORDING FLEXIBLE DISK DRIVE 1 2 APPENDIX Ill MASTER SPARE PARTS LIST MASTER SPARE PARTS LIST PARTS AND SUBASSEMBLIES Part Number Description of Part 171014 001 Drive Motor 171006 001 Track 00 Switch Assembly 171005 001 Write Protect Switch Assembly 171036 001 Logic PCBA 171111 001 Servo PC
38. With a Phillips screwdriver mount the Drive Motor Assembly to the chassis using the two 2 mount ing screws and the two 2 shoulder washers previously set aside 5 10 10 15 10 11 5 10 12 5 10 13 5 10 14 5 10 15 Reinstall the drive belt see Section 5 1 Plug Connector P21 into the Servo PCBA see Figure 5 18 Reinstall the Logic PCBA see Section 5 2 Check the Instantaneous Speed Variation ISV see Section 2 1 2 If the ISV meets the specification adjust the drive motor speed see Section 2 1 1 Recheck the ISV see Section 2 1 2 5 23 5 11 TRACK 00 SWITCH ASSEMBLY 5 11 1 Remove the Logic PCBA see Section 5 2 5 11 2 Cut the two 2 harnesses that hold the bundle of cables at the back of the drive motor and that attach the cables to the bottom of the chassis see Figure 5 20 Zt lt P gt DRIVE P4 lt 9 gt CABLE HARNESSES 2 Figure 5 20 Track 00 Switch Assembly Cable Harnessing 5 11 3 With a flat blade screwdriver remove the E ring from the Track 00 Switch Assembly adjustment screw located on the inside of the disk drive between the switch and its bracket see Figure 5 21 5 11 4 Move the head carriage toward the front of the disk drive i e away from the Track 00 Switch Assembly 5 11 5 With a Phillips screwdriver remove the mounting screw that attaches the Track 00 Switch Assembly to the chassis see Figure 5 22 5 11 6 Remove the Track 00 Switch Assembly by
39. aero bp CS eR a Sas tee Vd md ades A ated dE 1 8 1 16 6 1 Data Recording oc eoe TT IM DEMO 1 9 1 17 Interiace Electronics VIE E PRETI d RU adr 1 11 1 17 1 Interface Connector Pin Assignments J1 P1 1 11 1 17 2 Power Connector Pin Assignments 1 11 1 18 Option Select o vni reus qo ruo tor abu ON Ape AC 1 11 1 18 1 Input Line Terminations 1 11 1 18 2 DIVE Select costa es ee b Edu d d deae v ated d ed inns 1 14 1 19 Power Save ODIOT tats tee ec ade den ede Saba det a d due o 1 14 SECTION Il MAINTENANCE CHECKS AND ADJUSTMENTS 2 INMOGUCIION ore DOCE awe E wed Se Se re eee ru ier ome 2 1 2 1 Drive Motor Checks and Adjustments 2 1 2 1 1 Long Term Drive Motor Speed Checks and Adjustment 2 1 2 1 2 instantaneous Speed Variation Check 2 2 2 2 Cats Eye Alignment Check and Adjustment 2 3 2 2 1 GE Aligriment CDOCK 2 33 x o iar etc d o inks m Ron SOC ROS OA Re a be ee 2 3 2 2 2 2 6 TABLE OF CONTENTS Head Adjustment EUR CN EE E OUR e RU ARR Section Page Number Title of Section Nu
40. and gently pulling the retaining collar away from the front panel see Figure 5 10 5 6 4 Snap out the Activity LED Assembly from the LED grommet 5 6 5 Remove the entire Activity LED Assembly from the disk drive 5 6 6 Snap the new Activity LED Assembly into the front panel LED grommet 5 6 7 Push the retaining collar over the LED grommet 5 6 8 Install a new cable harness to attach the Activity LED Assembly and the Write Protect Switch Assem a the chassis by putting the cable harness through the two 2 holes in the bottom of the chassis see Figure NOTE Smooth out the cables before harnessing them 5 12 RETAINING COLLAR RETAINING COLLAR ES LED QI rommer gt N Figure 5 10 Activity LED Assembly Retaining Collar and LED Grommet Install a new cable harness around the bundle of wires including the new Activity LED Assembly cables that are located at the back of the drive motor see Figure 5 9 Reinstall the Logic PCBA see Section 5 2 Verify that the front panel Activity LED Assembly operates by using a computer or an exerciser 5 13 5 7 FRONT PANEL 5 7 1 Remove the Logic PCBA see Section 5 2 5 7 2 Using a pair of needle nose pliers remove the two 2 bushings located on the right hand and the left hand top sides of the front panel by pulling up on them while using a twisting motion see Figure 5 11 BUSHINGS 2 RAIL PINS 2 Figure 5 11 Front Panel Bushin
41. ap This causes a flux change to be stored on the disk drive See Figure 3 6 When the double frequency type encoding technique is used in which data and clock form the combined Write Data signal it is recommended that the repetition of the high to low transitions when writing all zeros be equal to the nominal data rate x 0 1 percent The repetition rate of the high to low transitions when writing all ones should be equal to twice the nominal data rate 0 1 percent The data transfer rate is 125 000 Bits Per Second BPS at single density it is 250 000 BPS at double density 3 9 WRITE SIDE WRITE GATE SELECT SELECT LOGIC LOGIC WRITE DRIVER 1 WRITE DRIVER 2 SIDE SELECT WRITE COILS TRIGGER BUFFER WRITE DATA N WRITE DATA PE zm ERASE N WRITE GATE WRITE PROTECT UNIT SELECT ERASE CURRENT SOURCE N INTERNAL EAD DISA WRITE Busy PEE Figure 3 6 Write Data Circuit Block Diagram Circuit Description Data comes on Pin 22 of the interface connector in pulse form Subsequently it is buffered by IC 2E then fed to a flip flop IC 5C two outputs of the flip flop through drive IC 2B alternately turn on Q1 and Q2 which alter nates the write current to the selected head R31 controls the amount of write current See Figure 3 7 Q3 is activated by the write gate through IC 2B IC 3B and IC 3D see Section 3 3 1 5 Q4 is designed to allow write current to flo
42. belt install it with the dark shiny side facing the pulleys see Figure 5 1 NOTE Put the drive belt on the small pulley first then on the large one 5 2 5 2 LOGIC PRINTED CIRCUIT BOARD ASSEMBLY 5 2 1 Unplug the eight 8 connectors on the Logic PCBA see Figure 5 2 FRONT J3 READ WRITE HEAD CONNECTORS MOUNTING SCREWS J4 POWER CONNECTOR BACK Figure 5 2 Logic PCBA Connectors and Mounting Screws 5 2 2 With a Phillips screwdriver remove the two 2 mounting screws that attach the Logic PCBA to the chassis see Figure 5 2 5 2 3 Slide the right side of the Logic PCBA toward the back of the disk drive about one half 1 2 inch 5 2 4 Lift the Logic PCBA off of the disk drive 5 2 5 Place the new Logic PCBA on the disk drive reversing the procedure in Sections 5 2 1 through 5 2 3 5 2 6 With a Phillips screwdriver install the two 2 screws that attach the Logic PCBA to the rails 5 2 7 Plug in all connectors ensuring that they are in their proper 51015 see Figure 5 2 NOTE Connector 6 is to be plugged in only on a single sided drive 5 3 5 3 SERVO PRINTED CIRCUIT BOARD ASSEMBLY 5 3 1 Detach connectors P20 and P21 from the Servo PCBA see Figure 5 3 located atthe back of the disk drive SPACER LY MOUNTING SCREWS 2 SPACER ZAI CONNECTORS 2 Figure 5 3 Servo PCBA Connectors Mounting Screws and Spacers 5 3 2 Using a Phillips screwdriver remove the two 2 mounti
43. ction is presented in theform of a table Each section contains four major parts 1 The section number A statement of the presenting condition A list of the possible causes of the condition gt U N The recommended action to be taken SECTION 4 1 4 2 4 3 CONDITION Not ready and or no index Will not seek or restore Will not write POSSIBLE CAUSE Diskette not inserted Door not closed Unit not selected Drive motor not turning Index sensor not connected Index sensor defective Interface not enabled Step motor disconnected Defective step logic Defective step motor Interface not enabled Heads or write protect switch not connected Write protect switch misadjusted Defective write logic Defective heads RECOMMENDED ACTION Insert diskette Close door Verify unit select and jumper configuration Verify interface drive motor on Check Connectors P13 P20 and P21 Verify drive belt installed Replace Servo PCBA Replace Drive Motor Assembly Check P10 Replace index sensor Verify interface direction step and select signals Check Connector P12 Replace Logic PCBA Replace Module Assembly Verify write enable select and write data interface lines Check Connectors P5 P6 and P8 Check write protect switch operation Replace Logic PCBA Replace Module Assembly SECTION 4 4 4 5 4 6 CONDITION Will not read
44. d as a delay The output at Pin 12 goes high 390 usec after the N WRITE signal goes true The N WRITE signal also goes to IC 3C Pin 1 which is configured as a one shot delay The output at Pin 13 goes low only 900 usec after it stops getting pulses at Pin 2 the pulse from the write data circuit and the N WRITE goes high or false The N ERASE signal is gated through IC 3B It is true 390 usec after a write true and 900 usec after a write false This signal enables the erase driver IC 2C R58 controls the erase current which is approximately 80 mA Pin 4 of IC 3C is the Not Internal Write Busy signal Itenables Q5 through IC 3E and gates twelve 12 volts to the selected head This signal also disables the data output at IC 5E Pin 11 The Not Internal Write Busy signal also enables the write flip flop 5C through IC 2E Pin 12 and Pin 13 Finally the Not Internal Write Busy signal goes to driver 2B Pin 10 and Pin 11 to disable the signal from the heads to the first stage amplifier using diodes CR11 and CR12 as gates 3 3 1 5 Write Data WRITE DATA Functional Description When the disk drive is selected the write data line provides the bit serial Write Data pulses that control the switch ing of the write current in the heads The write electronics must be conditioned for writing by the Write Enable line see Section 3 3 1 4 For each high to low transition on the Write Data line a flux change is produced at the head write g
45. d underneath and one of which is located at the back of the disk drive in the center counterclockwise one half 1 2 turn see Figure 2 6 with a Phillips screwdriver Turn the cam screw see Figure 2 6 counterclockwise with a flat blade screwdriver MODULE RETAINING MODULE RETAINING gn k ls FRONT Figure 2 6 Head Module Retaining and Cam Screws Observe the Cats Eye pattern at the magnetic head that is farthest out of alignment Using a flat blade screwdriver turn the cam screw until the Cats Eye pattern meets the conditions stated in Section 2 2 1 8 Tighten the three 3 module retaining screws see Figure 2 6 with a Phillips screwdriver Reverify the Cats Eye alignment see Section 2 2 1 Track 00 Stop Adjustment The Track 00 stop screw does not allow the carriage assembly to seek to a track lower than Track 00 2 6 2 2 3 2 2 2 3 3 2 2 3 4 2 2 3 5 2 2 3 6 2 2 3 7 2 2 3 8 2 2 3 9 2 2 3 10 2 2 3 11 2 2 3 12 2 2 3 13 The Track 00 stop screw should be adjusted when the Cats Eye pattern is adjusted or the carriage seeks to a track lower than Track 00 Apply power to the disk drive Select the disk drive with the control logic Monitor the output at Test Point 1 Monitor the output at Test Point 2 Set the dual channel wideband oscilloscope to read differentially A and B B inverted Insert an alignment diskette Read the information at Track OO T
46. door latch of he disk drive Check that the front latch opens and closes Note that when the door is opened the head arm raises Ensure that the front panel is secure Manually rotate the drive hub The drive hub should rotate freely Check that the PCBA s are secure Check that the connectors are firmly seated Check for debris or foreign material between the heads on Oo Notify the carrier immediately if any damage is noted 1 9 INTERFACE CONNECTIONS Signal connections for the disk drive are made via a user supplied 34 pin flat ribbon connector 3M Part Number 3463 0001 or equivalent This connector mates directly with the PCBA connector at the rear of the disk drive The DC power connector is a four pin connector Amp Mate N Lok Part Number 1 480424 0 which mates with the connector on the logic PCBA at the top rear of the disk drive The signal connector harness should be of the flat ribbon or twisted pair type have a maximum length of ten 10 feet and have a 22 to 24 gauge conductor compatible with the connector that is to be used Power connections should be made with 18 AWG cable minimum In addition the PCBA mounted DC power connector is keyed 1 10 CHASSIS GROUND To ensure proper operation of the disk drive the chassis should be connected to earth ground A 3 16 inch male QC lug located at the rear of the chassis is provided to facilitate this connection 1 10 1 Isolated Ground The power
47. ed Figure 1 4 illustrates the timing diagram for a write operation At t zO when the unit is ready the Write Enable in terface line goes true This enables the Write Current Source The Trim Erase control goes true 390 msec after the Write Enable interface line since the trim erase gaps are be hind the read write gap It should be noted that this value is optimized between the requirements at Track 00 and at Track 39 so that the effect of the trim erase gaps on previous information is minimized Figure 1 4 shows the information on the Write Data interface line and the output of the Write Waveform Genera tor which toggles on the leading edge of every Write Data pulse Note that a minimum of 4 usec and a maximum of 8 usec between Write Enable going true and the first Write Data pulse is only required if faithful reproduction of the first Write Data Transition is significant At the end of recording at least one additional pulse on the Write Data line must be inserted after the last signifi cant Write Data pulse to avoid excessive peak shift effects 1 9 WRITE ENABLE me ou B n o 8 TRIM ERASE INTERNAL WRITE BUSY if NWRITEDATA 4 1 1 2 1 WRITE WAVEFORM GENERATOR i Ld WRITE CURRENT 1 TE 4 l
48. erred to in conjunction with the following sections The data in the ensuing figures is primarily represented in simplified form 1 16 1 Index Pulse An index pulse is provided to the user system via the Index Pulse interface line The index circuitry consists of an Index LED an Index Photo Transistor and a Pulse Shaping Network As the index hole in the disk passes the In dex LED Photo Transistor combination light from the LED strikes the Index Photo Transistor causing it to con duct The signal from the Index Photo Transistor is passed to the Pulse Shaping Network which produces a pulse for each hole detected This pulse is presented to the user on the Index Pulse Interface line 1 16 2 Write Protect A Write Protect signal is provided to the user s system via the Write Protect interface line The Write Protect cir cuitry consists of a Write Protect sensor and circuitry that routes the signal that is produced When a write protected diskette is inserted in the disk drive the sensor is activated and the disables the write electronics and supplies the status signal to the interface 1 16 3 Track 00 Switch The level on the Track 00 interface line is a function of the position of the magnetic head assembly When the headis positioned at Track 00 and the stepper motor is at the home position atrue low level signal is generated at the interface 1 16 4 Spindle Drive System The Spindle Drive system consists of a spindle assembly
49. ge of the Read Data output pulse represents the true positions for the flux transitions on the diskette surface Test Point 1 and Test Point 2 see Figure 3 13 are provided to observe the differential output of the first stage of Read signal amplification Test Point 3 and Test Point 4 are provided to observe the differential output of the second stage amplifier and differentiated Read signal Test Point 5 is the output of the single shot used in the Read section nominally 1 0 usec for each flux transition detected Test Point 10 is signal ground Circuit Description The read signal comes from the selected head on the disk drive It is gated to the first amplifier IC 3A by the N WRITE signal to IC 2B Pin 11 and Pin 10 which forward biases diodes CR11 and CR12 Then the Read signal passes through C2 L1 L2 C3 C4 and C5 which is a bandpass filter The Read signal is then at the input IC 4A the differentiator which is also Test Point 1 and Test Point 2 The output of IC 4A goes through DC blocking capacitors C7 and C8 to the crossover detector IC 5B which dig itizes the AC signal This puts the signal into a standard TTL format IC s 5D and 5C comprise a comparator circuit Any pulses that occur outside of the normal duty cycle of IC 5B are eliminated IC 5D is an edge detector IC 5E acts as a one shot IC 5C is the actual comparator 3 15 w ro dle L3 L2K GBOun HEAD 1 2 w N os
50. gic PCBA see Section 5 2 Check the drive motor speed adjustment see Section 2 1 1 Check the Instantaneous Speed Variation see Section 2 1 2 5 36 5 16 5 16 1 5 16 2 LATCH PLATE ASSEMBLY Remove the Logic PCBA see Section 5 2 With a Phillips screwdriver loosen the two 2 mounting screws that attach the Latch Plate Assembly to the Cone Lever Assembly see Figure 5 32 5 16 3 5 16 4 5 16 5 5 16 6 5 16 7 Assembly 5 16 8 MOUNTING qs SCREWS 2 l LATCH INHIBITOR ASSEMBLY Figure 5 32 Latch Plate Assembly Mounting Screws and Latch Inhibitor Remove the two 2 mounting screws from the Latch Plate Assembly Remove the latch inhibitor and the Latch Plate Assembly from the disk drive While holding the Cone Lever Assembly down insert the new Latch Plate Assembly into its tracks Close the front door of the disk drive Still holding the Cone Lever Assembly down place the latch inhibitor on top of the Latch Plate With a Phillips screwdriver install but do not tighten the two 2 mounting screws that attach the latch inhibitor and the Latch Plate Assembly to the Cone Lever Assembly 5 16 9 5 16 10 Open the front door located in the front panel Insert a diskette into the disk drive 5 37 5 16 11 5 16 12 5 16 13 driver 5 16 14 Close the front door Adjusting the latch inhibitor align it so that it just touches the diskette as the front door is closed While holding
51. grams in this section In addition in the functional and circuit descriptions a specification line N MOTOR ON stands for the negative true motor on signal 3 2 PHYSICAL DESCRIPTION OF THE LOGIC PCBA The Logic PCBA is approximately 146 mm 5 75 inches long by 146 mm 5 75 inches wide Figure 3 1 contains an illustration of the placement of test points and connectors UPPER HEAO LOWER HEAD J3 READ WRITE HEAD LLL P5 TP TP12 O PROGRAMMABLE SHUNT KET SOCKET STEPPER MOTOR 1 SERVO JUMPER TP6 e P8 P9 2 2 LED INDEX o TERMINATOR SOCKET 2F UNUSED INTERFACE CONNECTIONS J1 INTERFACE CONNECTION PROTECT SWITCH PANEL TRACK 00 WRITE Figure 3 1 Logic PCBA 3 1 3 1 SYMBOLS AND ABBREVIATIONS fms Read Write Coils Normal Transistor Photo Transistor Driver Open Collector Output Driver Inverted Inverter Open Collector Output AND Gate nm Collector Output AND Gate Inverted 3 2 3 3 INTERFACE ELECTRONICS SPECIFICATIONS All interface signals are TTL compatible Logic true low is 0 4 V minimum Figure 3 2 illustrates the interface configuration The maximum interface cable length is ten 10 feet 150 OHMS t TWISTED PAIR t 741504 OR EQUIVALENT TRUE TRUE TRANSM
52. gs 5 7 3 Remove the retaining collar that attaches the Activity LED Assembly to the front panel by taking a pair of needle nose pliers and gently pulling the retaining collar away from the front panel see Figure 5 12 NOTE Slide the retaining collar over the Activity LED Assembly 5 7 4 Snap out the Activity LED Assembly from its grommet 5 7 5 With a Phillips screwdriver remove the two 2 mounting screws that attach the front panel to the chassis see Figure 5 13 NOTE These two mounting screws are located underneath the front end of the disk drive 5 7 6 Lift up the front panel and remove it from the chassis 5 14 RETAINING COLLAR p 27 41 RETAINING COLLAR 9 Grommet Figure 5 12 Activity LED Assembly Retaining Collar and Grommet Sd MOUNTING EN 2 Figure 5 13 Front Panel Mounting Screws 5 15 5 7 7 Taking the new front panel place the front door in its tracks on the front panel and place the new front panel on the rail pins see Figure 5 11 5 7 8 After upending the disk drive using a Phillips screwdriver reinstall the two 2 mounting screws that attach the front panel to the chassis see Figure 5 13 5 7 9 Push the Activity LED Assembly into its grommet NOTE The Activity LED Assembly usually makes a clicking noise when it is firmly pushed into the LED grommet 5 7 10 Push the Activity LED Assembly retaining collar over the back of the LED g
53. he design of an enclosure should incorporate a means to prevent contamination from loose items e g dust lint paper chad since the disk drive does not have a dust cover 1 11 3 Cooling System Requirements Heat dissipation from a single disk drive is normally 15 watts 51 Btu Hr under high line conditions When the disk drive is mounted so that the components have access to the free flow of air normal convection cooing allows operation over the specified temperature range When the disk drive is mounted in aconfined environment air flow must be provided to maintain specified air tem peratures in the vicinity of the motors the PCBA s and the diskette 1 12 DISKETTE CARE HANDLING AND STORAGE It is important that the diskette be cared for handled and stored properly so that the integrity of the recorded data is maintained Adamaged or contaminated diskette can impair or prevent recovery of data and can result in dam age to the Read Write heads of the disk drive The following list contains information how the diskette can optimally be cared for handled and stored 1 Keepthe diskette away from magnetic fields Do not touch the precision surface of the diskette with fingers Insert the diskette carefully into the disk drive until the backstop is encountered Do not bend or fold the diskette Put the diskette into its jacket when it is not in use Store the diskette at temperatures between 10
54. he trigger point 2 3 2 8 Tighten the index sensor s retaining screw with a Phillips screwdriver 2 3 2 4 Verify the indexes 2 4 COMPLIANCE CHECK AND ADJUSTMENT Compliance is the maximized output of the magnetic head when the pressure of the felt pressure pad is centered over the read write gap For single sided disk drives a compliance check and adjustment can be made in the field For double sided disk drives a compliance check and adjustment must be made at the factory 2 4 1 Compliance Check 2 4 1 1 Rest the disk drive on its cast base 2 4 1 2 Remove the two 2 screws that attach the Logic PCBA to the guide rails 2 4 1 3 Lift out the Logic PCBA and lay it on the disk drive 2 4 1 4 2 4 1 5 2 4 1 6 2 4 1 7 2 4 1 8 2 4 1 9 This allows the operator to reach inside the disk drive to move the magnetic head HEAD MODULE FRONT SENSOR S RETAINING SCREW ADJUSTMENT Figure 2 9 Index Sensor s Retaining Screw and Adjustment Apply power to the disk drive Select the disk drive with the control logic Insert a work diskette Write information on Track 34 Read the information on Track 34 Set up a dual channel wideband oscilloscope as follows Channel A Test Point 1 Channel B Test Point 2 Ground Test Point 10 2 10 BACK Read Differentially and B B Inverted Time Base 10 msec per Division External Trigger Test Point 7 Positive Edge 2 4 1 10 Read the output voltage 2 4 1
55. ibility in track posi tioning All signals required to control the data electronics are provided by the user system and are shown in the TM 100 disk drive functional block diagram see Figure 1 2 These control signals are 1 Select 2 Write Enable 3 Write Data 4 Side Select The Read Data composite signal is sent to the user system via the interface gt BIT CELL l 4 BIT PATTERN i 1 1 t 1 1 0 1 1 Figure 1 3 FM Recording Magnetization Profiles 1 16 6 1 Data Recording The write electronics consist of a Write Current Source a Write Waveform Generator an Erase Current Source the Trim Erase Control Logic and the Head Select Logic see Figure 1 2 The read write winding the magnetic head is center tapped During write operation current from the Write Current Source flows in alternate halves of the winding under control of the Write Waveform Generator The conditions required for recording i e unit ready must be established by the user system as follows 1 Drive speed stabilization occurs 250 msec after the drive motor is started 2 Subsequent to any step operation the positioner must be allowed to settle This requires 20 msec after the last step pulse is initiated i e 5 msec for the step motion and 15 msec for settling 3 The foregoing operations can be overlapped if requir
56. integral tachometer The servo control circuit suitably sized pul leys and the tachometer control the speed of the spindle The Read Write double sided head assembly is posi tioned by means of a stepper motor split band and a suitably sized pulley The Read Write Erase head assembly is a glass bonded ferrite ceramic structure It has a life in excess of 20 000 hours For diskette loading operator access is provided via a slot which is located at the front of the unit The electronic components of the disk drive are mounted on two Printed Circuit Board Assemblies PCBA s one of which logic is located above the chassis the other of which servo is mounted at the rear of the unit Power and interface signals are routed through connectors that plug directly into the logic PCBA 1 3 FUNCTIONAL DESCRIPTION OF THE DISK DRIVE The disk drive is fully self contained It requires no operator intervention during normal operation The disk drive consists of a Spindle Drive system a Head Positioning system and a Read Write Erase system The TM 100 1 is a single sided disk drive The TM 100 2 is a double sided disk drive The only difference be tween the two units is the number of heads in the disk drive The Logic PCB is identical in both models When the front door is opened access is provided for the insertion of a diskette The diskette is accurately posi tioned by plastic guides and by the front latch inhibitor The in out location is ens
57. ive is selected through the select jumpers and the MX jumper is not cut the drive electronics will be active but the front panel LED will not be on Normally Tandon Corporation s disk drives have no head load solonoid Hence the HS and the HM jumpers are not used In no case should both the HS and the HM jumpers be in since this would allow interaction between the Select signal and the Motor On signal However if the optional head load solonoid is installed IC 2C Pins 1 2 amp 3 drive it This is selected by either the HS or the HM jumper The HS jumper enables the head load solonoid driv er when the unit is selected the HM jumper enables the head load solonoid driver when the Motor On signal to the disk drive is true 3 3 1 2 Drive Motor Enable N MOTOR ON Functional Description When the Drive Motor Enable signal line logic level goes true low the disk drive s motor accelerates to its nomi nal speed of 300 rpm and stabilizes in less than 250 msec When the logic level goes false high the disk drive s motor decelerates to a stop Test Point 13 see Figure 3 4 is low true for the Motor On condition J1 P13 N MOTOR ON MOTOR POWER MOTOR GROUND N MOTOR ON Figure 3 4 Drive Motor Enable Schematic Diagram Circuit Description The disk drive s Motor On signal comes in on Pin 16 and is buffered through IC SE Pin 1 and Pin 2 to the servo board 3 6 3 3 1 3 Direction and Step Lines Two Lines DIR
58. k drive 5 9 15 Check to ensure that the aforementioned sensor cables do not touch the diskette the Cone Lever Assembly and the Carriage Assembly 5 9 16 Reinstall the Logic PCBA see Section 5 2 5 9 17 Adjust the index to data timing see Section 2 3 2 1 5 21 5 10 5 10 1 5 10 2 5 10 3 5 10 4 5 10 5 DRIVE MOTOR ASSEMBLY Remove the Logic PCBA see Section 5 2 Detach Connector P21 from the Servo PCBA located at the back of the disk drive Cut the cable harness that holds Connector P21 After turning the disk drive upside down remove the drive belt see Section 5 1 With a Phillips screwdriver remove the two 2 mounting screws and the two 2 shoulder washers that attach the Drive Motor Assembly to the chassis see Figure 5 18 DRIVE MOTOR ASSEMBLY CABLE HARNESS SHOULDER WASHERS 2 f SCREWS 2 Figure 5 18 Drive Motor Assembly Harnessing and Mounting NOTE Save the mounting screws and the shoulder washers Remove the Drive Motor Assembly from the chassis 5 10 6 5 10 7 Insert the pulley of the new Drive Motor Assembly through the bottom of the chassis see Figure 5 19 5 10 8 Rotate the Drive Motor Assembly until its two 2 tapped holes are aligned with two 2 of the holes in the chassis 5 22 5 10 9 SMALL Figure 5 19 Drive Motor Assembly Pulley NOTE Ensure that Connector P21 s cables are closer to the Servo PCBA than to the front of the disk drive
59. lips screwdriver install the mounting screw that attaches the index emitter holder to the Cone Lever Assembly 5 4 15 Harness the top index emitter cables to the Cone Lever Assembly see Figure 5 6 5 7 LEVER Figure 5 6 Cone Lever Assembly Cable Harness 5 4 16 Gather together and harness the stepper motor cables in two 2 places at the rear of the Cone Lever Assembly see Figure 5 5 5 4 17 front door of the disk drive to engage the cone and the hub 5 4 18 Ensure that the cone is centered in the lever shaft hole 5 4 19 With a Phillips screwdriver tighten the two 2 mounting screws that attach the Cone Lever Assembly to the chassis 5 4 20 Check to ensure there is clearance between the E ring and the washer when the cone is clamped the result of the front door being closed NOTE The cone shaft E ring should be between 0 010 and 0 025 above the cone lever when the Cone Lever Assembly is in the latched position 5 4 21 If necessary adjust the clearance by adding or deleting a washer located under the E ring see Figure 5 7 5 8 MOUNTING SCREWS 2 E RING DEPRESS THE CONE LEVER ASSEMBLY INTO THE LATCHED POSITION Figure 5 7 Cone Shaft and E Ring 5 4 22 Reinstall the Logic PCBA see Section 5 2 5 5 5 5 1 5 5 2 5 5 3 Remove the Logic see Section 5 2 Remove the Cone Lever Assembly see Section 5 4 see Figure 5 8
60. ll or a soldering iron to melt the plastic then remove the debris 5 17 Take care not to enlarge the hole in the chassis 5 8 7 Press in the new guide rail evenly 5 8 8 Push down on the front panel until it is back in place 5 8 9 After turning the disk drive upside down reinstall the two 2 mounting screws located near the front of the chassis with a Phillips screwdriver 5 8 10 After turning the disk drive right side up put the bushing over the front panel locating tab 5 8 11 Put a small drop of glue Permabond Superglue or other cyanoacrilic adhesive on top of the front panel locating tab 5 8 12 If the right hand guide rail has been replaced reloop the head cables over the two 2 guide rail posts 5 8 13 Reinstall the Logic PCBA see Section 5 2 5 8 14 If the left hand guide rail has been replaced verify the Write Protect Switch and its adjustment see Section 5 12 14 5 8 15 Reinstall the Logic PCBA see Section 5 2 5 18 5 9 INDEX ASSEMBLY 5 9 1 Remove the Logic PCBA see Section 5 2 5 9 2 Remove the harness that attaches the index emitter sensor cable to the Cone Lever Assembly see Figure 5 15 SENSOR zu CABLE 595 gt MOUNTING CABLE HARNESS Figure 5 15 Index Emitter Sensor Harnessing and Mounting 5 9 3 Remove the harness that holds the bundle of cables at the rear of the disk drive 5 9 4 With a Phillips screwdriver remove the mounting screw that attaches the index emi
61. ly in position on the left hand side of the chassis near the front 5 12 8 Using a Phillips screwdriver mount the new Write Protect Switch Assembly with its mounting screw 5 12 9 After smoothing out the Write Protect Switch Assembly cables and the Activity LED Assembly cables harness them to the bottom of the chassis routing the wires between the Drive Motor Assembly and the Track 00 Switch Assembly see Figure 5 25 5 12 10 Harness the bundle of wires at the back of the disk drive including the new Write Protect Switch Assembly cables in the bundle see Figure 5 25 5 12 11 Reinstall the Logic PCBA see Section 5 2 5 27 MOUNTING SCREW WRITE PROTECT SWITCH ASSEMBLY CHASSIS Figure 5 24 Write Protect Switch Assembly Mounting Screw and Connector P8 DRIVE p di CABLE HARNESSES 2 Figure 5 25 Write Protect Switch Assembly Cable Harnessing 5 28 5 12 12 Verify the output of the Write Protect Switch Assembly by raising and lowering the rear of the switch see Figure 5 23 5 12 13 Reverify the output of the Write Protect Switch Assembly 5 29 5 13 UPPER ARM ASSEMBLY SINGLE SIDED DRIVES ONLY 5 13 1 Remove the Logic PCBA see Section 5 2 5 13 2 Close the front door located in the front panel 5 13 3 Using a three sixteenth 3 16 inch thin wall nut driver remove the two 2 nuts that attach the upper arm and spring retainer to the Carriage Assembly see Figure 5 26 UPPER ARM
62. mber SECTION Il MAINTENANCE CHECKS AND ADJUSTMENTS 2 2 3 Track 00 Stop Adjustment 2 6 2 3 Index Checks and 2 8 2 3 1 Index Checks osea eer c ceps dons E NEG E uS 2 8 2 3 2 Index Adj stment xia a eR ACE Ce CO o 2 9 2 4 Compliance Check and Adjustment 2 9 2 4 1 Compliance Chock cereo eed Bere WES vet hoes ORUM Saca aces aes 2 9 2 4 2 Compliance AOJUSImelll A d SE es 2 11 2 5 Write Protect Switch Adjustment Procedure 2 12 SECTION Ill PRINTED CIRCUIT BOARD OPERATION 3 introduction sont genesi Eo bu te 3 1 3 1 Explanation of Symbols and Abbreviations 3 1 3 2 Physical Description of The Logic PCBA 3 1 3 3 Interface Electronics 3 3 3 3 1 Input Control Lines hte ive d WC 3 4 3 3 1 1 Select Lines NDSO NDS3 SEVA RERO RAN RE ee RON RC 3 5 3 3 1 2 Drive Motor Enable N MOTOR 3 6 3 3 1 3 Direction and Step Lines DIR N STEP 3 7 3 3 1 4 Write Enable N
63. n the disk drive is selected and the diskette is write protected the Write Protect signal line logic level goes true low The write electronics are internally disabled when the diskette is write protected It is recommended that the Write data line be inactive whenever Write Enable is false i e in a Read state J1 Pin 24 When the level on this line is false high the write electronics are enabled and the write operation can be per formed It is recommended that the controller not issue a Write command when the Write Protect signal is true low When a write protected diskette is installed in the disk drive Test Point 9 see Figure 3 12 is high 3 14 N TRACK 00 DRIVE SELECT P8 WRITE BS PROTECT 6 SWITCH NO J1 N WRITE GATE Figure 3 12 Write Protect Schematic Diagram Circuit Description The Write Protect signal comes in at Connector 8 Test Point 9 is held low when the switch is closed by a non write protected diskette The Write Protect output at Pin 28 of the interface is enabled at ICTF Pins 4 5 and 6 by the Drive Select signal 3 3 2 4 Read Data READ DATA Functional Description The Read Data interface line transmits the readback data to the controller when the disk drive is selected It pro vides a pulse for each flux transition recorded on the media The Read Data output line goes true low for a dura tion of one 1 usec for each flux change recorded The leading ed
64. nch wrench loosen the two 2 hex head screws that attach the Spindle 5 sembly to the top of the chassis see Figure 5 31 5 15 8 Rotate the retainer counterclockwise until its slot openings no longer are held by the two 2 hex head screws see Figure 5 31 5 15 9 Remove the Spindle Assembly by pulling it up and away from the chassis 5 15 10 Insert the new Spindle Assembly carefully into its mounting hole at the top of the chassis see Figure 5 31 5 34 RETAINER SLOT OPENING HEX HEAD SCREW HEX HEAD SCREWS 2 Figure 5 31 Spindle Assembly Retainer and Hex Head Screws 5 15 11 Engage the retainer by rotating it clockwise until its slot openings are under the two 2 hex head screws 5 15 12 Using a one quarter 3 inch wrench tighten the two 2 hex head screws that attach the bearing re tainer to the chassis see Figure 5 31 5 15 13 Lay the disk drive on its side 5 15 4 With a Phillips screwdriver while holding the hub insert the large pulley flat washer and the mounting screw into the bottom of the chassis see Figure 5 30 5 15 15 While holding the hub tighten the mounting screw see Figure 5 30 5 15 16 Check to ensure that the shaft does not wobble when the spindle turns NOTE A wobble may indicate a bad bearing 5 15 17 Reinstall the drive belt see Section 5 1 5 35 5 15 18 5 15 19 5 15 20 5 15 21 Reinstall the Cone Lever Assembly see Section 5 4 Reinstall the Lo
65. ng screws and the two 2 spacers that attach the Servo PCBA to the chassis NOTE Be sure to save the spacers and the mounting screws 5 3 3 Remove the Servo PCBA from the chassis 5 3 4 Stand up the disk drive on its front panel NOTE Be careful not to scratch the front panel 5 3 5 Place the two 2 spacers on top of the two 2 holes in the chassis 5 3 6 Place the new Servo PCBA on top of the two 2 spacers 5 4 Be sure to align the holes in the Servo PCBA with the holes in the spacers 5 3 7 Using a Phillips screwdriver attach the Servo to the chassis with the two 2 mounting screws NOTE If nylon screws are used ensure that they are installed at the same location 5 3 8 Plug Connectors P20 and P21 into their proper slots on the Servo PCBA P20 on the top and P21 the bottom see Figure 5 3 5 3 9 Check the drive motor speed see Section 2 1 1 5 3 10 Check the Instantaneous Speed Variation ISV see Section 2 1 2 5 5 5 4 LEVER ASSEMBLY 5 4 1 Remove the Logic PCBA from the disk drive see Section 5 2 5 4 2 Open the front door located in the front panel of the disk drive NOTE The Cone Lever Assembly automatically lifts up 5 4 3 Cut the tie wrap that attaches the top index cables to the Cone Lever Assembly 5 4 4 With a Phillips screwdriver remove the mounting screw that attaches the index emitter hoider to the Cone Lever Assembly see Figure 5 4
66. of Media Operating Nonoperating Head Settling Time Error Rates Maximum Soft Read Hard Read HeadLife Media Life Disk Speed Instantaneous Speed Variation Start Stop Time Transfer Rate Bits Per Disk Unformatted Recording Modes Typical Power 1 3 Industry Standard 5 25 diskette 85 85 mm 3 38 inches 149 1 mm 5 87 inches 203 2 mm 8 00 inches 1 45 Kg 3 2 pounds 10 C to 44 C 50 F to 112 F 40 C to 71 C 40 F to 160 F 20 to 80 Noncondensing 5 to 95 Noncondensing 15 msec Last Track Addressed 1 per 10 bits Recoverable 1 per 10 bits Nonrecoverable 20 000 Hours Normal Use 3 6x 10 Passes Per Track 300 rpm 1 5 Long Term 3 250 150 msec Maximum FM 125 000 BPS MFM 250 000 BPS 2 Million FM FM MFM MMFM 12 VDC 0 6 VDC 900 mA Average Maximum 5VDC 0 25 VDC 600 mA Average Maximum with 100 P P Ripple Remove the upper half of the inner container Remove the disk drive from the lower half of the inner container Check the model number and top assembly description against the packing slip Examine the contents of the shipping container for possible damage o o m Notify the carrier immediately if any damage is noted 1 8 PHYSICAL CHECKOUT OF THE DISK DRIVE Before applying power to the disk drive the following inspection procedure should be performed 1 Remove the plastic bag 2 Remove the cable harness from the
67. ol Pot If the drive motor s speed cannot be adjusted see Section IV Troubleshooting Guide Instantaneous Speed Variation Check The Instantaneous Speed Variation ISV checks the smoothness of the spindle s rotation This is determined by the disk drive system which consists of the drive motor drive belt pulleys hub and hub bearings 2 1 2 1 2 1 2 2 2 1 2 3 With the work diskette inserted write a 2F all ones pattern on any track Connect a wideband oscilloscope to Test Point 5 on the logic PCBA using Test Point 6 as a ground Set up a dual channel wideband oscilloscope as follows Vertical 2 Voits Per Division Time Base 1 usec Per Division Internal Trigger Positive Edge 2 1 2 4 2 1 2 5 2 1 2 6 2 1 2 7 2 1 2 8 2 1 2 9 2 2 Observe the following pattern see Figure 2 3 480 NSEC MAXIMUM Figure 2 3 ISV Pulse Pattern Measure the amount of jitter present on the leading edge of the third pulse see Figure 2 3 The lead ing edge of the third pulse should start 8 usec 240 nsec from the trigger pulse Jitter on the third pulse of greater than 240 nsec 480 nsec edge to edge indicates excessive ISV Confirm the measurement see Section 2 1 2 5 with a second work diskette If the ISV is excessive replace the drive belt see Section 5 1 and remeasure the Instantaneous Speed Variation ISV see Section 2 1 2 If the ISV is excessive replace the drive motor see Section 5 10
68. orisa high resolution device that can distinguish holes placed close together i e index sector holes in a hard sectored diskette 3 The Write Protect sensor disables the disk drive write electronics whenever a write protect tab is applied to the diskette see Section 1 13 1 4 DISKETTES The disk drive uses a standard 133 4 mm 5 25 inch diskette Diskettes are available with a single index hole or with index and sector holes Single index hole diskettes are used when sector information is pre recorded on the diskette Multiple index hole diskettes provide sector pulses by means of the Index sensor and electronics 1 5 MECHANICAL AND ELECTRICAL SPECIFICATIONS The mechanical and electrical specifications of the disk drive are listed in Table 1 1 1 6 INTERFACE CIRCUIT SPECIFICATIONS The interface circuits are designed so that a disconnected wire results in a false signal Levels True 0 4 V maximum False 2 4 V minimum 1 7 UNCRATING THE DISK DRIVE The disk drive is shipped in a protective container which when bulk packaged minimizes the possibility of dam age during shipment The following procedure is the recommended method for uncrating the disk drive 1 Place the shipping container on a flat work surface 1 2 TABLE 1 1 MECHANICAL AND ELECTRICAL SPECIFICATIONS Media Dimensions Height Width Length Weight Temperature Exclusive of Media Operating Nonoperating Relative Humidity Exclusive
69. peed accelerates to 300 rpm 1 5 R4 is adjusted for a motor speed of 300 rpm The motor supplies 12 volt AC tachometer signal to the servo board for regulation control Circuit Description The Motor On signal comes in at Pin 7 of the servo board see Section 3 3 1 2 This turns off Q2 allowing the sig nal to be sent to the base of Q1 The signal to the base of Q1 is the output of the regulator IC Pin 8 This is con trolled by the tach input at Pin 1 and Pin 2 of the servo board The tach signal is an AC signal of twelve 12 volts The other input to the regulator is from the voltage divider R3 R4 and R5 This voltage is adjustable by R4 a potentiometer to produce the proper amount of current through Q1 to the drive motor 3 18 ir od PART OF L1 PART OF P2 3 34H H2V arm a GND 3 3 MOTOR POWER 4121 MOTOR RETURN 7 4 MOTOR ON TACH PART OF PART OF i ad PZ O22 NOTES UNLESS OTHERWISE SPECIFIED 1 RESISTORS ARE IN OHMS 5 1 4 W 2 1 RESISTORS ARE 1 8 W 3 CAPACITORS ARE IN uF 20 35V Figure 3 16 tic Di m THE INFORMATION CONTAINED HEREIN IS THE PROPERTY OF TANDON NO PORTION OF THIS DATA SHALL BE RELEASED DISCLOSED USED OR DUPLICATED FOR USE IN PROCUREMENT OR MANUFACTURING WITHOUT SPECIFIC WRITTEN 3 19 PERMISSION FROM TANDON SECTION IV TROUBLESHOOTING GUIDE 4 INTRODUCTION This se
70. re 2 5 Verify that the smaller of the two 2 Cats Eye patterns is not less than 7595 in amplitude of the other one 2 2 1 9 2 2 1 10 2 2 1 11 2 2 1 12 2 2 1 13 2 2 1 14 2 2 1 15 2 2 1 16 2 2 1 17 2 2 1 18 2 2 1 19 2 2 1 20 2 2 1 21 EQUAL AMPLITUDE ON TRACK 16 TIME SCALE 20 ms DIV Figure 2 5 Cats Eye Pattern NOTE The 7595 figure is for use with an alignment diskette that has been verified against a standard alignment diskette Step the disk drive to Track 00 then step it back to Track 16 Reverify the Cats Eye pattern Step the disk drive to Track 26 or a higher track then step it back to Track 16 Reverify the Cats Eye pattern Switch to Head 01 the upper magnetic head Read Track 16 to verify the alignment of the upper magnetic head Verify the Cats Eye pattern Step the disk drive to Track 00 then step it back to Track 16 Reverify the Cats Eye pattern Step the disk drive to Track 26 or a higher track then step it back to Track 16 Reverify the Cats Eye pattern If all of the checks listed above verify or reverify the Cats Eye alignment of the magnetic head is acceptable If any of the checks listed above does not meet the conditions stated in Section 2 2 1 8 the corre sponding magnetic head must be adjusted 2 5 2 2 2 2224 2 2 2 2 2 2 2 3 2 2 2 4 2 2 2 5 2 2 2 6 2 2 3 2 2 3 1 Head Adjustment Turn the three 3 module retaining screws two of which are locate
71. rommet see Figure 5 12 5 7 11 Install two 2 new bushings on the right hand and the left hand front sides of the front panel see Figure 5 11 5 7 12 Put a small drop of glue Permabond Superglue or other cyanoacrylic adhesive on top of each bushing 5 7 13 Reinstall the Logic PCBA see Section 5 2 5 16 5 8 GUIDE RAIL 5 8 1 Remove the Logic PCBA see Section 5 2 5 8 2 With needlenose pliers remove the bushing from the front panel locating tab on the guide rail that is to be replaced see Figure 5 14 gt 2 5 LOCATING TABS 2 Soi 2 EN H CHASSIS LOCATING TABS 2 FD Figure 5 14 Front Panel Bushings and Locating Tabs 5 8 3 With a Phillips screwdriver remove the two 2 mounting screws located near the front of the disk drive underneath the chassis that attach the front panel to the chassis see Figure 5 13 5 8 4 Pull up the front panel slightly from the guide rail that is to be replaced NOTE If the right hand guide rail is to be replaced detach the head cables from the two 2 posts 5 8 5 With a flat blade screwdriver inserted between the guide rail and the chassis pry up from both of its ends the guide rail that is to be replaced and remove it 5 8 6 If one of the two 2 chassis locating tabs located underneath the guide rail that has been removed has broken off inside the chassis see Figure 5 14 clean out the hole completely using a one eighth 1 8 inch dri
72. s passed to the Differentiator which generates a waveform whose zero crossovers correspond to the peaks of Read signal Then this signal is fed to the Com parator and the Digitizer circuitry LINEAR OUTPUT FROM FILTER OUTPUT FROM DIFFERENTIATOR READ DATA INTERFACE NOTES 0 250 MILLISECONDS AFTER DRIVE MOTOR STARTS OR 20 MILLISECONDS AFTER STEP COMMAND OR t 0 100 u SECONDS AFTER TERMINATION OF WRITE BUSY WHICHEVER IS THE LATEST TIME Figure 1 5 Read Timing Diagram The Comparator and the Digitizer circuitry generate a 1 usec Read Data pulse corresponding to each peak of the Read signal Then the Composite Read Data signal is sent to the user system via the Read Data interface line 1 17 INTERFACE ELECTRONICS All interface signals are TTL compatible Logic true low is 0 4V maximum logic false high is 2 4V mini mum The maximum interface cable length is ten 10 feet It is recommended that the interface cable be flat ribbon cable having a characteristic impedence of 100 ohms or equivalent twisted pairs 1 17 1 Interface Connector Pin Assignments J1 P1 The interface connector pin assignments J1 P1 are listed in Table 1 2 1 17 2 Power Connector Pin Assignments The power connector pin assignments are listed in Table 1 3 1 18 OPTION SELECT 1 18 1 Input Line Terminations The disk drive has the capability of terminating the following input lines 1 Motor On 2 Direction Select 3 Step 4
73. the latch inhibitor in place tighten the two 2 mounting screws with a Phillips screw Reinstall the Logic PCBA see Section 5 2 5 38 APPENDIX PCB SCHEMATICS AND ASSEMBLY DRAWINGS L I R7 IK 10 c2 Ex d 4 RB IK 6 IK 724 cl R22 cit 2 cl 74 990 Ics 1 22 ait 3 pep a LJ Y 7 6 NERASE 463 10 2 150 7 154 NOTES UNLESS OTHERWISE SPECIFIED 390 THE INFORMATION CONTAINED HEREIN IS THE t PROPERTY OF TANDON NO PORTION OF THIS DATA SHALL BE RELEASED DISCLOSED USED OR DUPLICATED FOR USE IN PROCUREMENT OR LOGIC SCHEMATIC MANUFACTURING WITHOUT SPECIFIC WRITTEN PERMISSION FROM TANDON 45V TES x 15 4514 5 4 O 52 lt R44 2 3 4 1150 38 N INDEX INDEX 5v p jo IF 8 Ta SECTO PHOTO K TSY i ASSY x PROTECT IK E 24 14 6 TR 4 WKT JA V2F PROTECT o n SW m i 6 WRITE GATE 2 2 NDS 1878 BE EH NDSt 14 AC l2 3 4 5 poe 1365 our e o V 4 MOTO PWR 8123 2 23 MOTOR GND 3 B rop 2 FSV 2 R42 44V po ci NOTES UNLESS OTHERWISE SPECIFIED THE INFORMATION CONTAINED HEREIN IS THE 1 ALL RESISTORS ARE IN OHMS 1 4 W PROPERTY OF TANDON
74. tter sensor to the Cone Lever Assembly NOTE The Index Assembly is comprised of the index emitter sensor and the index detector sensor 5 9 5 Lift out the index emitter sensor holder from the disk drive 5 9 6 With a Phillips screwdriver remove the mounting screw from the bottom of the disk drive that attaches the index detector sensor holder to the chassis see Figure 5 16 5 9 7 Lift out the index detector sensor holder from the disk drive 5 9 8 Place the new index emitter sensor holder into the disk drive 5 9 9 With a Phillips screwdriver mount the new index emitter sensor holder to the Cone Lever Assemby using its mounting screw 5 19 INDEX DETECTOR gt SENSOR CABLE INDEX DETECTOR SENSOR HOLDER MOUNTING SCREW Figure 5 16 Index Detector Sensor Mounting Screw and Cable 5 9 10 Place the new index detector sensor holder in the top of the chassis 5 9 11 With a Phillips screwdriver mount the index detector sensor holder to the chassis using its mounting screw while holding the disk drive upside down 5 9 12 After turning the disk drive upright position all sensor cables see Figures 5 15 and 5 17 and smooth them out BUNDLE Figure 5 17 Index Emitter and Index Detector Sensor Cables and Bundle 5 20 5 9 13 Harness the index emitter sensor cables and the index detector sensor cables to the bundle see Figure 5 17 located at the rear of the disk drive 5 9 14 Insert a diskette into the dis
75. tween the two 2 wires of Plug 8 or that there is a non write protected output to the exercisor or computer i e a high at Pin 28 of J1 2 5 3 With a write protected diskette inserted verify that there is continuity between the two 2 wires of Plug 8 or that there is a write protect true output to the controller or exercisor low at Pin 28 of J1 Note A defective circuit board can be responsible for a write protect prob lem Test Point 9 should be high for a write protected disk drive and low for a non write protected disk drive 2 5 4 To adjust the write protect switch loosen the screw that holds the switch to the bracket on the side far thest from the front of the disk drive Move the switch up or down as required to satisfy the condition of Section 2 5 2 and Section 2 5 3 above see Figure 2 11 Figure 2 11 Write Protect Switch Adjustment SECTION III PRINTED CIRCUIT BOARD OPERATION 3 INTRODUCTION This section contains the interface description and the mechanical and the electrical adjustments necessary for the TM 100 1 and 2 Disk Drives 48 In addition Section 3 2 and Section 3 3 contain schematic diagrams of the Logic Printed Circuit Board Assembly PCBA installed in the disk drive Section 3 4 contains a schematic dia gram of the Servo PCBA installed in the disk drive 3 1 EXPLANATION OF SYMBOLS AND ABBREVIATIONS Table 3 1 contains a list of all of the symbols and abbreviations found on the schematic dia
76. two or more Select lines are in the true low state simultaneously see Figure 1 6 The Program Shunt is AMP Part Number 435704 7 The Program Shunt positions can be cut using AMP s Part Number 435705 The Program Shunt is installed in a dip socket At the user s option the Program Shunt may be removed and replaced by a dip switch In addition the user may choose to have the Program Shunts prepro grammed and or color coded by AMP For this service contact your local AMP representative 1 19 POWER SAVE OPTION As shipped from the factory the disk drive is configured to operate in a single drive system Jumper 0 ohm resis tor R51 maintains the power to the stepper motor whether or not the disk drive is selected However the jumper in position R51 may be moved to position R50 R50 removes the power to the stepper motor when the disk drive is not selected for a savings approximately equal to 3 8 watts per drive R50 is used at the time the disk drive is reselected the user must ensure the track location SECTION Il MAINTENANCE CHECKS AND ADJUSTMENTS 2 INTRODUCTION This section is designed for the use of the OEM Repair Department It contains the maintenance checks and ad justments that are used during the normal life of the disk drive Before applying power to the unit or doing any checks or adjustments visually inspect the disk drive to ensure that it has no missing or broken parts The following equipment is required
77. ured by the backstop Closing the front door activates the cone clamp system resulting in centering of the diskette and clamping of the diskette to the drive hub The drive hub is driven at a constant speed of 300 rpm by a servo controlled DC motor The magnetic head is loaded into contact with the recording medium whenever the front door is closed 1 1 The magnetic head is positioned over the desired track by means of a stepper motor band assembly and its asso ciated electronics This positioner employs a one step rotation to cause a one track linear movement When a write protected diskette is inserted into the disk drive the Write Protect sensor disables the write electronics of the disk drive and a Write Protect output signal is applied to the interface When performing a write operation a 0 33 mm 0 013 inch nominal data track is recorded Then this track is tunnel erased to 0 30 0 012 inch nominal Data recovery electronics include a low level read amplifier a differentiator a zero crossing detector and digitiz ing circuits No data decoding ability is provided in the basic disk drive The disk drive is also supplied with the following sensor systems 1 00 switch that senses when the Head Carriage assembly is positioned at Track 00 2 The Index sensor which consists of a LED light source and phototransistor is positioned such that a digital signal is generated when an index hole is detected The Index sens
78. urn the Track 00 stop screw counterclockwise two 2 turns with a 050 Allen wrench see Figure 2 7 TRACK 00 STOP SCREW 050 ALLEN WRENCH Figure 2 7 Track 00 Stop Slowly turn the Track 00 stop screw clockwise until the output amplitude shown on the dual channel wideband oscilloscope begins to decrease Turn the Track 00 stop screw counterclockwise until the amplitude stops increasing Turn the Track 00 stop screw counterclockwise an additional one eighth 1 8 turn 2 7 2 3 INDEX CHECKS AND ADJUSTMENT The index adjustment changes the time period from the index pulse to the start of the data The adjustment should be checked after the disk drive has been aligned see Section 2 1 1 or when diskette interchange errors are suspected 23 1 2 3 1 1 2 3 1 2 2 3 1 3 2 3 1 4 2 3 1 5 2 3 1 6 2 3 1 7 2 3 1 8 Index Checks Check the speed of the long term drive motor Apply power to the disk drive Select the disk drive with the control logic Set up a dual channel wideband oscilloscope as follows External Trigger Test Point 7 Positive Edge Read Differentially A plus B B inverted Channel A to Test Point 1 Channel B to Test Point 2 Time Base 50 usec Per Division Insert an alignment diskette Select Track 01 Select Head 00 the lower magnetic head Read the trigger point to the start of the first data pulse width see Figure 2 8 NOTE The specification is 200 usec 100 usec
79. w only after the five volt line is high enough to forward bias CR14 CR 15 and 16 which protects the disk from extraneous data being written when power is initially applied to the disk drive 3 3 1 6 Side Select SIDE SELECT Functional Description When the Side Select signal is true low Side 1 of the disk drive is selected for read write operations When this signal is false high Side of the disk drive is selected see Figure 3 10 The Side Select signal must be stable 3 10 23 RA s 9 CRI 26 Ik 1 4 8 CR cR A N INTERNAL SELECT WRITE BUSY ERASE 4 gt 4 WRITE PROTECT ORC com 12725 3 D 2 35 SWITCH 150 04 241590 N INTER WRITE Busy A R57 6 N WRITE GATE 24 2 SELECT Figure 3 7 Write Data Schematic Diagram 3 11 during an entire read or write operation This signal is best implemented in synchronization with the Device Select line signal see Section 3 3 1 1 Circuit Description The Side Select signal comes in on Pin 32 of the interface connector If this signal is high Side 0 is selected This signal is buffered through IC 2E see Figure 3 8 From there the Side Select signal is sent through IC 2B and IC 3E to Drive Q7 or Drive Q6 Drive Q7 sends currentto the upper head Head 1 Drive Q6 sends current to the low er head Head 12V Pe 23 N INTERNAL Ik WRITE BUSY

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