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Страница 2: ...ch 24 1986 36010 001 Revision B Seagate reserves the right to change without notice the specifications contained in this manual Seagate 920 Dise Drive Seotts Valley CA 95066 4544 USA Tel 408 438 6550 Telex 176455 SEAGATE SCVL ...
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Страница 4: ... DC Power Connector J3 10 2 4 Frame Grounding Lug JI0 10 3 0 DRIVE CONFIGURATION 11 3 1 Drive Configuration Shunt J9 MLC Ol 11 3 2 Drive Select Il 3 2 1 Daisy chain 11 3 3 Radial 12 3 4 Write Fault 12 3 5 Life Test 12 4 0 CONTROL INPUT SIGNAIS 13 4 1 Head Select 2 21 22 23 13 4 2 Write Gate 13 4 3 Step 14 4 3 1 Buffered Seek 14 4 3 2 Slow step Single track 15 4 3 3 Auto truncation 16 4 4 Direction...
Страница 5: ... 31 8 2 Motor Speed Control PC Board 20249 XXX 31 8 2 1 Hall Effect Transducer 32 8 2 2 Speed Reference Circuit 32 8 2 3 Pulse Shaper 32 8 2 4 Integrator 32 8 2 5 Current Limit 32 8 2 6 Microprocessor Motor On 32 8 2 7 Motor Drivers 32 8 2 8 Dynamic Brake 32 9 0 FIELD SERVICE 33 9 1 Test Point Data PC Board 20292 XXX 33 9 1 1 DifferentiaI Read Filter Test Points 1 and 2 34 9 1 2 Track 0 Sensor IC ...
Страница 6: ...Signal Driver Receiver Combination 22 FIGURE 20 Write Operation PC Board 20292 XXX 22 FIGURE 21 Write Operation PC Board 20243 XXX 24 FIGURE 22 17 Sector 512 Byte Sector Format Example 25 FIGURE 23 Read Operation PC Board 20292 XXX 26 FIGURE 24 Read Operation PC Board 20243 XXX 27 FIGURE 25 MPU PC Board 20292 XXX 29 FIGURE 26 MPU PC Board 20243 XXX 30 FIGURE 27 Motor Speed Control PC Board 20292 X...
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Страница 8: ... Average Latency Recording Density Track Density Cylinders Tracks Discs Recording Method Data Transfer Rate 3 600 RPM 1070 8 33 msec 10 560 BPI FCI 550 TPI 306 1 224 1 MFM 5 0 Megabits second PHYSICAL SPECIFICATIONS 1 3 Height Width Depth Weight 1 63 inches max 41 4 mm 5 75 inches max 146 05 mm 8 00 inches max 203 2 mm 3 00 lbs 1 4 Kg RELIABILITY SPECIFICATIONS 1 4 MTBF PM MTTR Service Life 11 000...
Страница 9: ...maxi mum total of sixteen 16 per drive Cylinder Zero will be free of defects 1 5 1 5 1 Operating Nonoperating 1 5 2 Operating Nonoperating 1 5 3 Operating Maximum Wet Bulb Nonoperating 1 5 4 Operating Nonoperating 1 5 5 ENVIRONMENTAL SPECIFICATIONS AMBlENT TEMPERATURE 10oC to 45 oC 50 OF to 113 OF 40 C to 60 C 40 F to 140 F TEMPERATURE GRADIENT 10 C hr 18 F hr max Below condensation RELATIVE HUMID...
Страница 10: ...r on 5070 Both seek and non seek conditions 3 2 Amp 1 0 Amp typical 5 VDC Voltage Tolerance inc ripple Maximum Current at Power on POWER 5070 Both seek and non seek conditions 1 2 Amp 1 0 Amp typical 17 Watts typical INPUT NOISE RIPPLE 1 1 The maximum permitted ripple is 50 mV peak to peak on either 12 Volts or 5 Volts INPUT NOISE FREQUENCY 20 MHz max on both the 12 VDC and 5 VDC Hnes 1 2 AMPS r 1...
Страница 11: ...es Left or right Refer to Figure 2 for mounting dimensions The drive should not be tilted front to back in any position by more than 5o For optimum performance the drive should be formatted in the same orienta tion as it will be mounted in the host system A minimum clearance of0 050 inch should be allowed around the entire perimeter of the drive to allow for cooling airflow and motion during mecha...
Страница 12: ...ling and ESD hazard Do not touch the PCB edge connectors board components or the printed cir cuit cable without observing static discharge precautions Handle the drive by the frame only It is strongly recommended that the drive always rest on a padded surface until it is mounted in the host system ST212 PRODUCT MANUAL Rev B 5 ...
Страница 13: ... connector JI Figure 3 indicates connector dimensions and Table llists the pin assignments A host drive interconnection is illustrated in Figure 4 With the drive resting on a padded surface oriented with the Main Control PCB up and the edge connectors toward you 11 is to your left and J2 is on the right Refer to Figure 7 JI pins are numbered 1through 34 with the even pins located on the component ...
Страница 14: ...ED WITH DRIVE SELECT FLAT RIBBON OR TWISTED PAIR 20 FT MAX 1 RESERVED 2 3 1 RESERVED 4 5 WRITE GATE 6 7 4 SEEK COMPLETE 8 9 TRACK _ 10 11 1 WRITE FAULT 12 13 HEAD SELECT 2 14 15 4 RESERVED 16 17 1 HEAD SELECT 21 18 19 t INDEX 20 21 4 READY 22 23 4_ STEP 24 25 i DRIVE SELECT 1 26 27 4_ DRIVE SELECT 2 28 29 DRIVE SELECT 3 30 31 1 DRIVE SELECT 4 32 33 4 DIRECTION IN 34 5 VOLTS OC 4 l 5 VOLTS RETURN 3...
Страница 15: ... drive resting on a padded surface oriented with the Main Control PCB up and the edge connectors toward you J2 is to your right and JI is on the left Refer to Figure 7 J2 pins are numbered 1 through 20 with the even pins located on the compo nent side of the PCB A key slot is provided between pins 4 and 6 Pin 2 is la beled The recommended mating connector for J2 is AMP ribbon connector part number...
Страница 16: ...MFM WRITE DATA 16 15 GROUND 17 MFM READ DATA 18 MFM READ DATA 20 19 GROUND FLAT RIBBüN OR TWISTED PAIR 20 FT MAX DRIVE SELECTED 1 2 RESERVED 3 4 4 RESERVED 5 6 i RESERVED 7 8 4 RESERVED 9 RESERVED 10 GROUND 11 i 12 MFM WRITE DATA 13 MFM WRITE DATA 14 GROUND 15 4 16 4 MFM READ DATA 17 MFM READ DATA 18 GROUND 19 20 1 _1 FIGURE 6 Data Signais HOST ST212 PRODUCT MANUAL Rev B ST212 J2 9 ...
Страница 17: ...ss than five feet may use 18AWG wire and AMP 61314 4 strip pins For applications requiring cable lengths greater than five feet 14AWG wire is recommended using AMP 61117 4 strip pins 2 4 FRAME GROUNDING LUG J10 110 is an AMP Faston part number 61761 2 It is located on the casting be tween and below the host drive interface connectors The recommended mat ing connector is AMP part number 62187 2 Ref...
Страница 18: ...he controller to select and address the drive Pins 1 2 shorted enable ï RIVE SELECT 1 Pins 3 4 shorted enable DRIVE SELECT 2 Pins 5 6 shorted enable DRIVE SELECT 3 Pins 7 8 shorted enable DRIVE SELECT 4 DAISY CHAIN 3 2 1 Each drive in the chain must be selected as either DRIVE SELECT 1 2 3 or 4 so that only one DRIVE SELECT UNE activates a device The last drive in the chain must have the 220 330 r...
Страница 19: ...DATA CABLE DATA SIGNALS DRIVE 4 J DATA CABLE L I CJ1 TERMINAlOR PACK INSTALLED H DATA CABLE r J2 AS SHIPPED L 3 4 WRITE FAULT The WRITE FAULT signal is intemally latched A selectable option is provided to clear tbis latch The standard configuration with the shorting block removed resets the WRITE FAULT latch when WRITE GATE is dropped and reasserted after the detected fault has been cleared With p...
Страница 20: ... True 0 0 VDC to 0 4 VDC at 1 48 mAmp max FaIse 2 5 VDC to 5 25 VDC at 1 250 JLAmp open collector Termination 220 330 resistor pack FIGURE 10 Control Signais Driver Receiver Combination 7438 20 FT MAX FLAT CABLE OR TWISTED PAIR HEAD SELECT 20 21 22 23 4 1 These signaIs aIlow the selection of each Read Write head in a binary code se quence The Hnes are numbered 0 through 3 HEAD SELECT Hne 2 is the ...
Страница 21: ...d if the period between pulses is greater than or equal to 3 msec DIRECTION IN must be stable 100 nsec before the leading edge of the first step pulse and remain stable for 100 nsec after the last pulse in a string of Step p ulses Step pulses issued between 500 p sec and 3 msec may be lost If excessive Step pulses are issued which would cause a seek inward beyond cylinder 306 or outward beyond Cyl...
Страница 22: ...eneral Step Timing SLOW STEP Single Track 4 3 2 In Slow Step the stepper motor is settled and SEEK COMPLETE is issued 20 msec max after the leading edge of the last Step pulse FIGURE 13 Slow step Timing DRIVE SELECi 1 lL 100nsec min JL 1oonsec min DIRECTION IN Il Il 6M R J V ffippeT 911 1 ï lJ _ STEP J j 100nsec min 1 100nsec min U Lrll f f La oo Jf 1 SEEK COMPLETE 1 _ ST212 PRODUCT MANUALIRev B 1...
Страница 23: ...212 will either reenter Auto Truncation mode with DIRECTION IN false or step the remain ing cylinders with DIRECTION IN true I EXCESSIVE STEP PULSES RECOGNIZED TRACKJj 1 jt SEEK 1 20msec max 1 1 1 1 2sec max I FIGURE 14 Auto truncation Timing 4 4 DIRECTION IN DIRECTION IN defines the direction the Read Write heads will move when the STEP line is pulsed With DIRECTION IN true each pulse causes the ...
Страница 24: ...CE L1NE DRIVER FROM INTERFACE DRIVE SELEeTED L1NE RECEIVER TRACK0 STEP PULSES DRIVE SELEeT 1 DRIVE SELEeT 2 READY DRIVE SELEeT 3 DRIVE SELEeT 4 DIREeTlON SEEK COMPLETE WRITE FAULT AeTlVITY LED INTERNAL INDEX ST212 PRODUCT MANUAL Rev B ...
Страница 25: ...m high to low or the leading edge is valide 5 3 TRACK This signal is low true only when the Read Write heads are positioned at Cylinder Zero Track 0 is the only cylinder that provides interface recognition The drive is designed to recalibrate to Track 0 during power on and Auto Truncation oper ations Track 0 may also be accessed via conventional Buffered Seek and Slow Step modes After Track 0 is t...
Страница 26: ...y drive logic at power on 2 100 nsec max after the leading edge of a Step pulse 3 If either 5 Volts or 12 Volts are detected as unsafe WRITE FAULT 5 6 This signal indicates that a condition exits at the drive which if not corrected may cause an incorrect write operation WRITE FAULT will remain true until the condition causing the fault is corrected The controller should edge detect this signal WRI...
Страница 27: ...lly monitors the 5 and 12 Volt lines for a low voltage condition If Volts 15070 low or 12 is 20070 low the DC unsafe signal is activated IC 6H pin 25 causing 1 Write current to be disabled 2 The microprocessor is reset 3 The fault line is activated IC 6H pin 24 4 The heads are deselected If multiple heads are selected the Read Write LSI will disable the write circuitry and send a Write Fault to th...
Страница 28: ...n If 5V is 15070 low or 12V is 20070 low Write current will be disabled the microprocessor reset the fault line acti vated and the beads deselected HEAD SELECT COMPARATORS 5 8 2 When a single head is selected normal operation IC 70 pins 1 and 2 will be high If more than one head is selected the voltage will increase at 70 pin 4 forcing its output low An attempt to write with no head selected will ...
Страница 29: ...BOARD 20292 XXX WRITE GATE WRITE DATA PROCESSING READIWRITE READIWRITE HEADS LSI IC6H MFM DIFFERENTIAL WRITE DATA HEAD SELECT FIGURE 20 FROM INTERFACE Write Operation PC Board 20292 XXX In order to Write the following conditions must be satisfied WRITE FAULT inactive SEEK COMPLETE active READY active DRIVE SELECT active Write Gate active 6 1 1 MFM WRITE DATA WRITE DATA is transmitted by a differen...
Страница 30: ... to be written activates either pin 7 or 8 of the preamp LSI IC 3H When writing to the inner heads 2 and 3 Write current is reduced to lessen the problems of pulse crowding PRECOMPENSATION 6 1 4 TABLE 3 Precompensation Pattern Precompensation is recommended on cylinders 128 through 306 in order to achieve optimum performance The optimum amount of precompensation is 12 nsec for both early and late ...
Страница 31: ...NE RECEIVER DifferentiaI Write Data precompensated MFM is received from the controller and changed to single line It is then fed into the pulse generator 7K which changes square wave data to pulse data Depending on whether plus or minus data is to be written either pin 7 or pin 9 of 7H is activated The amount of current to be written is primarily established by R53 When writing to the inner heads ...
Страница 32: ... the write splice created This field assures valid reading of field number 7 and allows the 13 bytes required for Data VFO lock A field of all zeros to sync the VFO for the data field Al Hex with a dropped clock to noti fy the controller that data follows FS Hex defming that user data follows This area available for user data Cyclic Redundancy Check information used to verify the validity of the u...
Страница 33: ...n pin 12 will force the decoder to choose a nonexistent head During read operations the head center tap is set at approximately 5 Volts by the Read Write LSI IC 6H pin 27 By referencing 0 to 5 Volts actual ground appears as 5 Volts which eliminates the necessity of a negative power source normally required by the LSI preamp IC 3H 6 4 3 LSI PREAMP With the head center tap active data from the selec...
Страница 34: ...tely 5 Volts by Zener Diode CR2 By referencing 0 to 5 Volts actual ground appears as 5 Volts which eliminates the necessity of a negative power source normally required by the LSI preamp LSI PREAMP 6 5 2 With the head center tap active data from the selected head will flow into the preamp This preamp amplifies the read signal and also acts as a high pass filter LOW PASS FILTER 6 5 3 This filter ne...
Страница 35: ...y falls below the zero cross threshold a spurious data bit will be generated Such false bits are ignored by delaying the clocking data bit le 6L past the potential point of highest drop 5 7 LINE DRIVER At this point raw digital data is changed to differential data providing immuni ty to common mode noise during transmission 28 ST212 PRODUCT MANUAL Rev B ...
Страница 36: ... in the idle mode the MPU loops waiting for step pulses The MPU also monitors its reset line pin 39 for a Iow signal from IC4D which causes the MPU to reinitialize Upon receiving a step pulse the MPU pauses for 500 p sec to allow for addi tional pulses before executing the seek operation Every incoming pulse will reset the 500 p sec timer The seek will not begin until the last pulse is received Wh...
Страница 37: ... and the drive is then ready to accept inputs from the controller When in the idle mode the MPU loops waiting for step pulses The MPU also monitors power and should the power drop by approximately 20070 it will revert to the initialization routine described above Upon receiving a step pulse the MPU pauses for 500 p sec to allow for addi tional pulses before executing the seek operation Every incom...
Страница 38: ... control L81 pauses until 10 Volts is reached before applying current ta the motor drive transistors Lf 10 Volts is not achieved within approximately 1 second the motor control L81 will time out and will not apply power ta the motor drive transistors When current is applied the spindle motor control L81 sets the motor speed to 3 600 RPM nominal The motor speed is crystal controlled YI with a fre q...
Страница 39: ... levels by IC lA pin 7 whose output determines the current flow per revolution through each motor phase 8 2 5 CURRENT LIMIT Transistor Q6 senses the current level drawn during motor start up and limits it to 3 S Amps by controlling the on time of 2A pins 3 12 8 2 6 MICROPROCESSOR MOTOR ON This signal is maintained low by the microprocessor as long as the index sensor indicates motor spin up within...
Страница 40: ... accounts for more Winchester drive damage than aIl other fac tors combined Your ST212 is designed for consistent and reliable service across a wide range of environmental factors It is however a precision instrument and when transporting or shipping a unit please ensure that the drive is correctly packed in the original Seagate or approved substitute container FIGURE 29 Test Point Locations PC Bo...
Страница 41: ...entiaI Read Filter 9 1 2 TRACK 0 SENSOR IC 38 PIN 1 IC 3B pin 1 may be used to monitor the Track 0 sensor A high logic level indi cates valid Track 0 The microprocessor requires the stepper motor to he at phase A and the Read Write heads to be at Cylinder Zero before it will output a valid Thlck 0 signal 9 1 3 INDEX SENSOR TEST POINT 9 lest point 9 may be used to monitor the Index sensor Only the ...
Страница 42: ...9 2 9 2 1 These points may be used to monitor Differentiai Read Data The typical am plitude of the signal resulting from adding the two channels is 160 mVolts The signal is observed at Cylinder Zero head 0 or 1 A full track record of high fre quency data 0000 or 1111 will typically resemble Figure 30 ST212 PRODUCT MANUALIRev B 35 ...
Страница 43: ...he Read Write heads at Cylinder Zero before a valid lfack 0 signal will be issued 9 2 4 INDEX SENSOR TEST POINT 6 Test point 6 may be used to monitor the Index Sensor Only the leading edge of the pulse is valid A typical signal will resemble Figure 3J Test point 6 is used to monitor the spindle motor during speed adjustment Ad just at R3 MLC OO access through the side of the frame for a period of ...
Страница 44: ...5 disconnected This will insure that if the replacement is damaged it not alter data on the disco Avoid creasing the cable and inspect after this operation MOTOR CONTROL PC BOARD REMOVAL MLC OO ONLY 9 3 2 If the motor control board is replaced the spindle speed must be adjusted Refer below for adjustment procedure Required Tools T lO Torx driver or standard blade screwdriver l Remove the Main Cont...
Страница 45: ...the silver tab aligns with the sensor 6 Using the shim verify that the gap is 030 Tighten the screw l MOUNTING SCREW i z J J CLAMP Q INDEX SENSOR TAB see notes 4 5 9 3 4 INSTALLING THE OPTIONAL FULL HEIGHT FRONT PANEL Required Tools T IO Torx driver Depending on how the unit was shipped from the factory the unit may have a half height Front Panel already installed To remove 1 Remove the Main Contr...
Страница 46: ...t be tampered with 1 If installed remove the Front Panel 2 Disconnect the Track 0 Sensor connector P8 Slide the wires down between the casting and the frame Free the harness from the white retaining clip on the casting Refer to Figure 36 3 Remove the sensor Do not tamper with the Interrupter Arm set screw This is set and sealed at the factory SENSOR o r STEPPER MaTOR f JL INTERRUPTER ARM ST212 PRO...
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Страница 51: ...44 20249 XXX ST212 PRODUCT MANUAL Rev B ...
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