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Notes: CPS/TMA/008 (Week 13)
Names: »2803A «
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└─⟦9753ba4d5⟧ Bits:30006173 8" Wang WCS floppy, CR 0253A
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2803A/bel
BSP/820923
INTRODUCTION TO CDC LOGIC 13:1:1 45
CAMPS
Locate component on PBC-Cards in the Mini Module Drive
and in the Storage Module Drive.
Spot checks.
CAMPS Classroom
Lecture Groupwork
MMD & SMD
Disk-Drives
Overheads whiteboard
OEM Manuals
2803A/bel/
BSP/820923
DISK DRIVE THEORY 13:1:2 45
CAMPS
Explain briefly the theory behind Disk Drives and the
"Winchester Principles"
(Not checked)
CAMPS Classroom
Lecture
Overheads
Whiteboard
2803A/bel/
BSP/820923
MMD AC/DC Power Distr. 13:1:3 45
CAMPS
Describe the Power Distribution of the MMD-Drive.
Check the AC and DC voltages of the Power Distribution.
Exercises during lesson
Questionnaire at conclusion of lesson.
CAMPS Classroom.
(Comm. Cen.)
Lecture Groupwork
Demo Hands-on
Overheads Mini Module Drive
Whiteboard
2803A/bel/
BSP/820923
MMD Power-Up Seq.First seek 13:1:4 45 CAMPS
Describe the principles in a MINI MODULE DRIVE Power
Up.
Describe the principles in a MMD first seek sequence.
Discussion during lesson.
Questionnaire at conslusion of lesson.
CAMPS Classroom
Lecture Groupwork
Discussion
Overheads
Whiteboard
MMD Diagrams
2803A/bel/
BSP/820923
Servodsc,Circuit,"Quadbits" 13:1:5 45 CAMPS
Describe the purpose of the Servo Disk.
Describe the function of the servo circuit.
Describe the principles of quadbits and Servo Head
Tracking.
Discussion during lesson.
Questionnaire at conslusion of lesson.
CAMPS Classroom
Lecture Groupwork
Discussion
Overheads
Whiteboard
MMD Diagrams
2803A/bel/
BSP/820923
Servo Sys.Dir.Seek,RTZ.Seek 13:1:6 45 CAMPS
Describe the servo system (on track/off track).
Describe a normal seek (in brief)
Describe a return to home operation.
Discussion during lesson.
Questionnaire at conslusion of lesson.
CAMPS Classroom
Lecture Groupwork
Discussion
Overheads
Whiteboard
SMD Diagrams
2803A/bel/
BSP/820923
Read/Write, Fault Logic 13:2:1 45 CAMPS
Explain the principles of recording and recovering
data from a magnetic disk.
Understand the Diagnostic Fault Codes.
Discussion during lesson.
Questionnaire at conslusion of lesson.
CAMPS Classroom
Lecture Groupwork
Discussion
Overheads
Whiteboard
MMD Diagrams
2803A/bel/
BSP/820923
MMD Disk Drive Strip 13:2:2 45 CAMPS
Strip-Down the Mini Module Drive
On the spot
Comm. Cen.
CAMPS Classroom
Demo Hands on
MMD - Drive
The instructor
OEM Manuals
2803A/bel/
BSP/820923
MMD Disk Drive Strip 13:2:3 45 CAMPS
Strip-Down the Mini Module Drive
On the spot
Comm. Cen.
CAMPS Classroom
Demo Hands-on
MMD - Drive
The instructor
OEM Manuals
2803A/bel/
BSP/820923
Clock Index/Sector Hd.Sel. 13:2:4 45 CAMPS
Explain the Clock Signals necessary for Drive Operation.
Describe index and sector detection.
Describe the Head Selection operation.
Explain (Emergency) Retract Operation.
Discussion during lesson.
Questionnaire at conclusion of lesson.
CAMPS Classroom
Lecture Groupwork
Discussion
Overheads
Whiteboard
MMD Diagrams
2803A/bel/
BSP/820923
ADJUSTMENTS (PRACT) 13:2:5 45 CAMPS
Perform important adjustments at the Drive Level.
Through exercises during lesson.
COMM. CEN.
CAMPS Classroom
Hands-on Training
Mini Module Drive & Field Test Unit
Oscilloscope
Multimeter
OEM Manuals
2803A/bel/
BSP/820923
TB216 FIELD TEST UNIT 13:2:6 45 CAMPS
Describe the TB216 Field Test Unit.
Use the TB216 Field Test Unit.
On the Spot.
CAMPS Classroom
COMM. CEN.
Lecture Groupwork
Demo
TB216 Tester
OEM Manual
2803A/bel/
BSP/820923
TB216 Tester 13:3:1 45 CAMPS
Fully use the TB216 Field Test Unit.
On the Spot.
CAMPS Classroom
Comm.CEN.
Groupwork
TB216 Tester
2803A/bel/
BSP/820923
MMD FAULT FINDING 13:3:2 45 CAMPS
Perform Various Fault Finding procedures necessary
to correct errors and faults in the Mini Module Drive.
Various Exercises.
COMM. CEN.
CAMPS Classroom
Groupwork
Mini Module Disk Drive
Field Unit Tester
(Oscilloscope, Multimeter)
OEM Manuals
2803A/bel/
BSP/820923
MMD FAULT FINDING 13:3:3 45 CAMPS
Perform Various Fault Finding procedures necessary
to correct errors and faults in the Mini Module Drive.
Various Exercises.
COMM. CEN.
CAMPS Classroom
Groupwork
Mini Module Disk Drive
Field Unit Tester
(Oscilloscope, Multimeter)
OEM Manuals
2803A/bel/
BSP/820923
MMD FAULT FINDING 13:3:4 45 CAMPS
Perform Various Fault Finding procedures necessary
to correct errors and faults in the Mini Module Drive.
Various Exercises.
COMM. CEN.
CAMPS Classroom
Groupwork
Mini Module Disk Drive
Field Unit Tester
(Oscilloscope, Multimeter)
OEM Manuals
2803A/bel/
BSP/820923
MMD FAULT FINDING 13:3:5 45 CAMPS
Perform Various Fault Finding procedures necessary
to correct errors and faults in the Mini Module Drive.
Various Exercises.
COMM. CEN.
CAMPS Classroom
Groupwork
Mini Module Disk Drive
Field Unit Tester
(Oscilloscope, Multimeter)
OEM Manuals
2803A/bel/
BSP/820923
MMD FAULT FINDING 13:3:6 45 CAMPS
Perform Various Fault Finding procedures necessary
to correct errors and faults in the Mini Module Drive.
Various Exercises.
COMM. CEN.
CAMPS Classroom
Groupwork
Mini Module Disk Drive
Field Unit Tester
(Oscilloscope, Multimeter)
OEM Manuals
2803A/bel/
BSP/820923
SMD AC DISTR.DC.POW.Bl.DIA. 13:4:1 45 CAMPS
Describe the Power Distribution of the SMD-Drive.
Check the AC and DC Voltages of the Power Distribution.
Exercises during lesson.
Questionnaire at conclusion of lesson.
CAMPS Classroom
(COMM. CEN)
Lecture Groupwork
Demo Hands-on Training
Overheads Storage Module Drive
Whiteboard
2803A/bel/
BSP/820923
SMDPOW-UP SEQ.LOA.SEEK,SERVO 13:4:2 45 CAMPS
Describe the Principles in a STORAGE MODULE DRIVE POWER
UP.
Describe the head loading and the load seek.
Describe the functions of the servo system.
Discussion during lesson.
Questionnaire at conslusion of lesson.
CAMPS Classroom
Lecture Groupwork .
Discussions.
Overheads
Whiteboard
SMD Diagrams
2803A/bel/
BSP/820923
SMD SERVO SYS. + DISK 13:4:3 45 CAMPS
Describe the purpose of the servo disk.
Describe the principles of Dibits and Servo Head Tracking.
Discussion during lesson.
Questionnaire at conclusion of lesson.
CAMPS Classroom
Lecture Groupwork
Discussion
Overheads
Whiteboard
SMD Diagrams
2803A/bel/
BSP/820923
DIR.SEEK, RTZ.SEEK 13:4:4 45 CAMPS
Describe the principles behind the Direct Seek (coarse,
fine, on cylinder).
Describe the Return to Cylinder Seek.
Discussion during lesson.
Questionnaire at conclusion of lesson.
CAMPS Classroom
Lecture Groupwork
Discussion
Overheads
Whiteboard
SMD Diagrams
2803A/bel/
BSP/820923
READ/WRITE OPERATION 13:4:5 45 CAMPS
Describe the principles behind the Read/Write functions.
Explain Fault and error conditions.
Describe the Emergency Retract Functions.
Discussion during lesson.
Questionnaire at conclusion of lesson.
CAMPS Classroom
Lecture Groupwork
Discussion
Overheads
Whiteboard
SMD Diagrams
2803A/bel/
BSP/820923
INDEX/SECT.HEAD SEL.INTR.AD 13:4:6 45 CAMPS
Describe the index Detection and Sector Detection Principles.
Describe the Head Select Principles.
Explain an appropriate method of approaching an adjustment
problem.
Discussion during lesson.
Questionnaire at conclusion of lesson.
CAMPS Classroom
Lecture Groupwork
Discussion
Overheads
Whiteboard
SMD Diagrams
2803A/bel/
BSP/820923
SMD ADT/FAULT FINDING 13:5:1 45 CAMPS
Do specific Adjustments on the STORAGE MODULE DRIVE.
Find faults and errors in the STORAGE MODULE DRIVE.
Through exercises.
CAMPS Classroom/COMM. CEN.
Groupwork and study.
Hands-on Training
Storage Module Drive
The Instructor
OEM Manuals
2803A/bel/
BSP/820923
SMD ADT/FAULT FINDING 13:5:2 45 CAMPS
Do specific Adjustments on the STORAGE MODULE DRIVE.
Find faults and errors in the STORAGE MODULE DRIVE.
Through exercises.
CAMPS Classroom/COMM. CEN.
Groupwork and study.
Hands-on Training
Storage Module Drive
The Instructor
OEM Manuals
2803A/bel/
BSP/820923
SMD ADT/FAULT FINDING 13:5:3 45 CAMPS
Do specific Adjustments on the STORAGE MODULE DRIVE.
Find faults and errors in the STORAGE MODULE DRIVE.
Through exercises.
CAMPS Classroom/COMM. CEN.
Groupwork and study.
Hands-on Training
Storage Module Drive
The Instructor
OEM Manuals
2803A/bel/
BSP/820923
SMD ADT/FAULT FINDING 13:5:4 45 CAMPS
Do specific Adjustments on the STORAGE MODULE DRIVE.
Find faults and errors in the STORAGE MODULE DRIVE.
Through exercises.
CAMPS Classroom/COMM. CEN.
Groupwork and study.
Hands-on Training
Storage Module Drive
The Instructor
OEM Manuals
2803A/bel/
BSP/820923
REVISION 13:5:5 45 CAMPS
Check his own knowledge of the topics of the week.
Analyses of questionnaires
Discussion of various topics
CAMPS Classroom
(COMM. CEN.)
Informal Discussion/Study.
Lecture
Demo
Overheads
Whiteboard
MTNP Module Drive & Storage Module Drive
OEM Manuals
2803A/bel/
BSP/820923
REVISION (cont'd) 13:5:6 45 CAMPS
Check his own knowledge o fhte topics of the week.
Analyses of questionnaires
Discussion of various topics
CAMPS Classroom
(COMM. CEN.)
Informal Discussion/Study.
Lecture
Demo
Overheads
Whiteboard
MTNP Module Drive & Storage Module Drive
OEM Manuals
2803A/ktd
13:1:1 BSP/821102
INTRODUCTION TO CDC LOGIC SYMB L/GW
CDC LOGIC: OEM-
Manuals
Introduction Introducing the OEM-manuals (various sections
to CDC - OEM and the contents of the sections)
MANUALS Introduce the CDC abbreviations.
LOGIC M̲M̲D̲: Introduction to CDS-Symbology (Sec 3 -
SYMBOLOGY Diagrams)
S̲e̲c̲t̲ ̲3̲: Logic symbols have an element identifier
OH 1 and a PHYSICAL LOCATION COORDINATE.
P 3-2 ELEMENT IDENTIFIER defines the type of circuit
involved (see Microcircuit Man).
COORDINATE DESIGNATOR refers to a physical
location of components on cards.
XXYY COORDINATES:
XX: UP-SIDE OF CARD (EXPOSED SIDE)
YY: ALONG CARD-ASSY
OH 2 An example deriving a physical loc based
P 3-3 on a XXYY-GRID PATTERN (XXYY = 1920)
OH 3 Intersheet referencing is shown in details
P 3-6 on this example
OH 4 Back panel seen from wire wrap side shows
P 3-11 loc of W-W-pins.
OH 5 The CHASIS MAP shows the configuration of
SHEET 2 Drive Chasis Map. It is also a key to cards:
Functional Name, Cross Ref No, and Module
Type Identifier.
2803A/ktd
13:1:1 BSP/821102
INTRODUCTION TO CDC LOGIC SYMB L/GW
LOGIC S̲M̲D̲:
SYMBOLOGY SMD III
OH 6 Qualifying symbol: Determines the function
P 1-1 of the circuit.
Element ID: Defines the type of circuit included.
Physical location code: The chip is located
at C2. The section of the chip used is B.
OH 7 This Intersheet Referencing shows examples
P 1-3 on going from one sheet (X REF #) to another
sheet (X REF #) with signal either "leaving"
or "entering" the sheet at Hexagons or JACK/PLUGS.
OH 8 This is a Physical Arrangement Description
P 1-8 of the drive. Physical Location Codes and
Titles plus X REF # on page 1-5, 1-6, 1-7.
OH 9 This wire wrap pin will be positioned at
P 1-9 card location # A09 Row # OH on the column
B
OH 10 This shows the relative position of the Back-
P 1-10 panel, and all other card assemblies in the
drive.
2803A/ktd
13:1:2 BSP/821102
DISK DRIVE THEORY, "WINCHESTER" L/DE/GW
CYLINDER OH 11 The Disks of the Mini Module Drive and the
CONCEPT Storage Module Drive comprise information
recorded on the surfaces. To recover recorded
data Read/Write heads are used. They are
all aligned vertically on a carriage that
is able to be moved by a positioner.
On MMD two heads/surface.
On SMD one head/surface.
OH 12 The MMD Disk is formatted so that 5 data
surfaces each comprise two sets of Data Tracks.
The Servohead reads one set of servo tracks.
OH 13 The Disc Controller will format each sector
on all tracks on the data sufaces.
The Gabs in each sector are necessary for
mechanical tolerances (between servohead
and recording head).
The Address field comprises 9 bytes info
on Cylinder, write protection, Bad sector,
and the Total Sector Address. The datafield
comprises 548 bytes of user data.
2803A/ktd
13:1:3
BSP/821102
MMD AC/DC POWER DISTRIBUTION L/DE/GW
Introduction OEM- MMDI and MMDII will be used in this lesson
to POWER Manuals
DISTRIBUTION
OH 1 The MINI MODULE DRIVE is divided into a
MMD/3-1 number of major areas, one of them being
POWER SYSTEM FUNCTIONS. This area consists
of Power Distribution of AC-power and DC-power
(Other areas will be discussed throughout
this course).
POWER FUNCTIONS describes how the drive provides
the voltages necessary for drive operation.
AC-POWER OH 2 The DRIVE POWER SUPPLY is powered from
DISTRIBUTION MMD/3-4 the Site Power AC-distribution.
The input AC-voltage is filtered and distributed
to the drive fans, the Motor Control Triacs
and the DC-Voltage Regulator Board.
The AC-power is protected from overload by
the CB1 Circuit Breaker.
The Fuse F1 is an overcurrent protective
device located on the outside of the power
supply.
The Fuses F2 - F5 are four overcurrent protective
devices lodated within the power supply.
The Thermostate S1 protects the Power Supply
from overheating.
2803A/ktd
13:1:3 BSP/821102
MMD AC/DC POWER DISTRIBUTION L/DE/GW
DC-POWER OH 2 The DC-Voltage Regulator Board receives
DISTRIBUTION MMD/3-4 its power from the secondary winding of the
T1 transformer.
The +/-24V AC from Trafo T1 is rectified
to an unregulated +/-24V DC for use in drive
operations like Motor control, Brake Control,
Heat Positioning, and Retract.
OH2A DC VOLT PART I & II show the circuit which
x REF comprises the recitifier from which the
#22 +/-24V DC is derived. Also shown is the
OH 2B circuit from which the regulated +/-5V is
x REF derived
#23
OH 2 The +/-24V DC and +/-5V DC are output from
the power supply to the Logic Chasis
OH 3 This shows the Power Supply with CB1, F1,
MMD/2-17 AC-Cable, outlets, and +/-5V ADJ.
OH 3A And the physical location in the MMD
MMD/2-9
POWER CABLING OH 4 This shows the Power Cabling to and from
? the Power Supply. Also shown is the Logic
Cabling between Logic Chasis and R/W Motherboard.
2803A/ktd
13:1:3 BSP/821102
MMD AC/DC POWER DISTRIBUTION L/DE/GW
POWER CABLING DEMO Physical location of Power Supply and Various
Cables is shown on the MMD.
SELFSTUDY ON OH 5 OH 5 shows the Voltage Programming Plug P07
MMD CABLING X REF and the MMD Grounding Diagram.
DIAGRAMS #011
OH 6
X REF
#412
OH 7
X REF
#012
OH 8 OH6, OH7, OH8, OH9 show the MMD Cabling
X REF Diagrams.
#013 The Student will use the manuals
OH 9 and make a selfstudy on the Cabling and
X Ref Plugs in order to familiarize himself
#414 with the MMD, what is located where, and
how
it is connected.
DISCUSSION EX 1 3 exercises coming up later in this course
OF EXERCISES EX 2 will need a little preparation. The
EX 3 instructor will go through each step of exercise
EX1, EX2, and EX3 and discuss with the student
what to perform, how to perform, and where
(on the drive) to perform the single steps
in each exercise.
QUESTIONNAIRE At conclusion of the lesson, at QUESTIONNAIRE
is handed out to each student. 5questions/5
min.
2803A/ktd
13:1:4
BSP/821102
MMD POWER UP SEQ. FIRST SEEK L/DE/GE
POWER ON OH 1 In order to initialize a power-up, the
SEQUENCE MMDI/3-8 Circuit Breaker CB1 must be in its ON position.
The Power On Abbreviated Flowchart describes
what happens during a Power On Sequence.
Numbers in () Refer to X REF # on Diagrams.
The power-up sequence is under the control
of an initialization program under the direction
of the MPU.
During initialization, the MPU performs some
self diagnostic tests:
a cyclic redundancy check test of the
ROM
a WRITE/READ test of the programmable
peripheral datalines, and
a test of the interrupt system
If a fault (MPU FAULT: CODE 06) is detected
which prevents a further power-up action,
the drive will halt and fail to become ready.
OH 2 Power-on Sequence Circuitry shows the start
MMDI/3-7 drive signals at PIA-1. Together with the
flowchart, signals and sequence are explained.
OH 5 OH 5 is used to define "Outer Guard Band"
MMDI/3-50 and "Home Position". The Disk Format illustrates
the Servo Disk (with the Servo Track Info)
and Data Disks.
FIRST SEEK OH 3 The Power-up seek is the operation that moves
OH 4 the heads from the Retract Position to the
MMDI/3-76 Home Position which is TRACK [.
Power-up Seek (sheet 2) shows in details
this operation (Also shown in brief at abbreviated
Flowchart).
2803A/ktd
13:1:4 BSP/821102
MMD POWER UP SEQ. FIRST SEEK L/DE/GE …0e…
MECHANICAL OH 6 The Drive Motor is the device that rotates
FUNCTIONS MMDI/3-14 the Disks. Disk rotation serves two purposes:
One is to enable the encoding of cylindrical
data,
and the other one is to create a cushion
of air on the disk surfaces to allow the
heads to move over the disk surfaces without
actually contacting them. This Disk Motor
is mounted on the frame assy.
OH 7 A drive belt transfer motion from the drive
MMDI/3-15 motor to disks which are mounted on a spindle.
The motor starts during the power on sequence
after the brake has been released. The Drive
motor/spindel accellerates until it reaches
3600 r/min.
OH 8 A Speed Transducer is mounted next to the
MMDI/3-16 Spindle Pulley. The transducer generates
signals which are monitored by the drive
speed logic.
If spindel speed 3000 RPM, normal seek
and read/write operations can take place.
If spindel speed 3000 RPM, a Retract Operation
will occur.
OH 6 Drive Motor temperature is monitored by the
Thermal Switch. If the motor overheats, the
thermal swithc opens to remove power from
the motor and initiate a not up to speed
retract operation.
The drive motor cannot be restarted until
it cools. Then the thermal reset button must
be pushed to restart it.
2803A/ktd
13:1:5
BSP/821102
SERVO DISK, SERVO CIRCUIT, "QUADBITS" L/DE/GW
INTRODUCTION OH 1 The Drive positions the moveable heads over
MMDI/3-49 the desired cylinder on the disk during a
seek operation.
The servo circuit takes care of the positioning
by means of prerecorded signals from the
servo disk.
The positioner is an actuator on which all
heads are mounted and aligned vertically.
All head moves together when the actuator
moves.
OH 2 The 80MB Disk Format and Head Configuration
MMD/3-50 shows that the drive has five Data Recroding
Surfaces (with two Recording Zones per surface)
and 10 Recording Heads (one associated with
each data recording zone). Also one servo
surface and one servo head is present.
A Data Zone consists of Landing Zone, Behind
Home, and 823 Data Tracks.
SERVODISK A Servo Zone consists of a Landing Zone/Guard
Band 2, Guard Band 1, Servo Tracks (0-822),
and Inner Guard Band.
OH 3 The servo tracks, which are concentric bands
MMDI/3-60 of tracks, comprise servo information in
the form of prerecorded signals. These signals
have a layout like bar magnets with north
and south poles.
The way the poles are arranged, determines
the type of servo track as either an "even"
track or an "odd" track.
All tracks between the Guard Bands are recorded
in alternate bands of even and odd tracks.
During disk rotation, the servo head reads
these magnetic changes.
The resultant signal of reading an even and
an odd track is called QUADBITS.
2803A/ktd
13:1:5 BSP/821102
SERVO DISK, SERVO CIRCUIT, "QUADBITS" L/DE/GW
QUADBITS OH 4 The Quadbits is a servobyte consisting of
MMDI/3-61 4 position bits trailed by 2 clockbits.
Reading a servobyte:
ODD TRK QUAD BIT
EVEN TRK QUAD BIT
ODD TRK QUAD BIT
EVEN TRK QUAD BIT
ID BIT
SYNC BIT
NOT ON TRACK conditions result in EVEN/ODD
signals become larger
ON TRACK CENTER conditions are characterized
by equal magnitude in signals from EVEN and
ODD tracks, which means that the servo head
is centered precisely between EVEN and ODD
tracks.
GUARD BANDS OH 3 Two Outer Guard Bands and one Inner Guard
Band do have a modified servo byte pattern.
The Guard Bands serve the purpose of informing
the drive that the heads are not in legal
READ/WRITE data areas. GB2 also serves as
a landing zone for the actuator in its retract
position.
SERVO CIRCUIT OH 5 The purpose of the servo circuit it to
MMDI/3-54 convert electrical signals from the controller
into electrical motion to position the read/write
heads accurately. When that is done, magnetic
pulses can be transferred to and from the
disks.
The actuator (and all heads) moves in or
out by applying current to the voice coil,
and the servo circuitry controls the movement
under the direction of the microprocessor
circuit.
OH 6 The MPU sets up the move by comparing NEW
MMDI/3-58 address with OLD address. Calculation on
direction and ideal speed to reach New Address
is performed by the MPU, and the MPU program
generates IN Drive or OUT Drive pulses to
the voice coil.
2803A/ktd
13:1:6 BSP/821102
SERVO SYSTEM, DIRECT SEEK, RTZ. SEEK L/DE/GW
SERVO SIGNALS OH 1 The Servo Track signals are read by the
MMDI/3-62 Servo Head. A Servo Decode Circuitry Amplifies
the signals and detects the peaks and outputs
a +/- Position Signal.
If ON TRACK condition exists, the four peaks
in the Quadbits are of equal magnitude.
OFF TRACK condition implies that a set of
peaks has an amplitude which is different
from the other set of peaks.
The amplitudes of a set of peaks are proportional
to the distance of the servo head from centerline
of the two adjacant tracks.
Servo head sensing only ODD/EVEN TRACK simply
means that DATA HEADS are positioned between
two DATA TRACKS.
The signals (Quadbits) sensed by the servo
head have to be decoded in order to use it
for positioning.
The servo decode circuitry gates the quadbit
pulses in the peak detector with Demod Gate
A and Demod Gate B.
The decoded +/- position signals are used
by the analog servo circuitry to determine
cylinder (Track Crossing) during seek, on
cylinder at the end of seek and monitoring
on Of Cylinder condition during the track
following phase of the fine servo operation.
OH 2 The +/- position signals are applied to level
MMDI/3-66 detectors to perform info for final position.
When an On Cylinder condition is true, a
level detector supplies an active output
to the MPU via the PIA 1 in order to enable
the track following phase of the fine servo.
The fine servo monitors the on/off track
condition in the track following mode.
An Off Cylinder condition will be deteted,
and the MPU will be interrupted and caused
to call up a program routine to return the
heads to On Cylinder condition.
2803A/ktd
13:1:6 BSP/821102
SERVO SYSTEM, DIRECT SEEK, RTZ. SEEK L/DE/GW
NORMAL SEEK OH 3 The p̲o̲w̲e̲r̲ ̲u̲p̲ ̲s̲e̲e̲k̲ is the operation of moving
MMDI/3-79 the heads from Retract position to Home Track
([). That is one direction: Toward Center
from the edge.
The n̲o̲r̲m̲a̲l̲ ̲s̲e̲e̲k̲ is the operation of mooving
the heads from one location to another in
one of the two directions: OUT or IN.
Going from a higher numbered track to a lower
numbered track involves a movement in the
OUT-direction of the actuator.
OH 3 Normal seek sheet 1-3 explains in detail
OH 4 how the seek is performed. Here is a short
OH 5 version:
After the unit has been selected, the address
of desired new cylinder is verified for Max
Seek Fault and Not Fixed Head select.
The MPU takes over and compares new cyl.
add. with old one. From that the MPU decides
which direction and how many tracks to go;
from a ROM table the MPU program selects
a value representing calculated velocity
for the distance.
Current to Voice Coil is applied, and the
Actuator moves in desired direction while
a Track-to-go counter is decremented at cylinder
crossings. Velocity varies with tracks-to-go.
(Tracks-to-go)-2 implies that the actuator
position is in Fine Servo Mode and thus under
the control of the Analog Position Signals.
2803A/ktd
13:1:6 BSP/821102
SERVO SYSTEM, DIRECT SEEK, RTZ. SEEK L/DE/GW
RETURN TO ZERO OH 6 The R̲e̲t̲u̲r̲n̲ ̲t̲o̲ ̲Z̲e̲r̲o̲
̲S̲e̲e̲k̲ is the operation
of
SEEK MMDI/3-84 moving the heads from Data Tracks to Home
Track ([). That is one direction: Toward
edge from Center. This is initiated by either
the controller or by the MPU program.
A̲ ̲C̲o̲n̲t̲r̲o̲l̲l̲e̲d̲ ̲R̲T̲Z̲:
The RTZ seek resembles a normal seek operation:
A MPU-program directs the sequencing of the
operation, and monitors the status of the
drive.
There is one destinction from a normal seek:
Instead of stopping when the actuator reaches
the designated track, it carries on out into
the Guard Band Zone, stops, moves inward
until it arrives at the Home position.
A̲ ̲M̲P̲U̲ ̲R̲T̲Z̲:
If it should happen that the drive performs
an illegal seek into the IGB, the MPU will
be interrupted and initialize a RTZ seek.
2803A/ktd
13:2:1
BSP/821102
READ/WRITE OPR. FAULT LOGIC L/GW
INTRODUCTION In order to perform Read/Write operations
on the Data Surface of Disks, o̲n̲e̲ read/write
(OH 1) head must be involved.
As all heads are moving at the same time
to desired cylinder, one head to read/write
information on disk has to be selected by
the Head Selection Circuits.
The controller commands the Drive to select
the Head located over the Data Surface where
the Read/Write Data operaton is to be performed.
OH 1 The Read/Write Circuit Block Diagram shows
the principles of Recording and Recovering
Data on a magnetic Disk.
The Read/Write Heads (one selected by the
Head Select Circuits) perform the Read/Write
operation.
1) Write Circuits:
During a Write operation, data are received
from Controller and transferred to heads
and recorded on the Disk.
2) Read Circuits:
During a Read operation, recovered data
from the disk are received from the heads
and transferred to the controller.
WRITING/READING OH 2 In order to write data,
a current is
DATA MMDI/3-92 passed through a read/write coil within the
recording head. This generates a magnetic
flux flow in the coil which creates a flux
field across a gap in the head.
The magnetic coating (Iron Oxide Particles)
is magnetized - all in same direction (like
bar magnets) - within the flux field. It
has one polarity.
To change the polarity, the flux field has
to be reversed, which means that the direction
of the current flow will have to be reversed.
The amount of oxide particles to be magnetized
depends on the flux field ampletude which
again is a function of the amount of current.
Data are written onto the disk by reversing
the current through the head in a certain
pattern while the disk is in motion. One
flux change defines one data bit.
2803A/ktd
13:2:1 BSP/821102
READ/WRITE OPR. FAULT LOGIC L/GW
Reading data is almost the opposite operation:
The disk rotation positions magnetized Iron
Oxide Particles underneath the head gab which
causes a magnetic flow in the coil. This
flow induces a current flow.
Each flux reversal generates a reversed current
flow pulse. These pulses represent data bits.
RECORDING OH 3 Actual recorded wareforms and timing are
TECHNIQUES MMDI/ slightly different from theoretical ones
due
3-103 to the nature of the electromechanical devices
which do not operate perfect.
Write Irregularity is shown as an Actual
Recording compared to an Ideal Recording.
OH 4 The Technique of reading the binary digits
MMDI/ recorded on disk involves a carefully
3-101 monitoring of the frequency of flux reversals.
The MMD uses the method of Modified Frequency
Modulaton (MFM).
READ CIRCUIT OH 5 Read operations are initiated when the Analog
MMDI/ Read Data Detection Circuits are enabled.
3-106 The recorded data sensed by the head is received
as analog signals and processed into analog
data (MFM) to be used by the Analog to Digital
Converter.
The converter performs the change of analog
data into Digital Data (MFM), which are sent
to the Data Separator.
After the MFM data has been converted to
NRZ, these Read Data are sent to the Controller.
OH 6 Analog Read Data Detection Circuits and Read
MMDI/3- Analog to Digital Converter Logic and Timing
107 explains in detail the nature of processing
& 108 and converting the Read Data signals.
WRITE CIRCUIT OH 7 Write operations are initiated when the
MMDI/ drive is allowed to start processing serial
3-114 NRZ data received from the controller.
The NRZ data is converted to MFM and compensated
for Peak Shift (which is an effect that degrades
read accuracy by distortion of waveform.
Electromechanical devices are not ideal).
2803A/ktd
13:2:1 BSP/821102
READ/WRITE OPR. FAULT LOGIC L/GW
WRITE CIRCUIT OH 7 The Write Driver receives the write data
(cont'd) MMDI/ (MFM) and produces the necessary amount of
3-114 current to be used in recording data on
disk by the head.
A Write Current Control Circuit serves the
purpose of reducing write current amplitude
proportional to the distance from Center.
Thus even numbered head writes with a reduced
current amplitude compared to odd numbered
heads. (Why is that?)
OH 8 The Write Driver Circuit and Timing explains
MMDI/ in detail the nature of processing the compensated
Write data in the Write driver to generate
Write current for Read/Write head.
FAULT CODES There are two categories of errors:
AND ERROR
CONDITIONS 1) Errors which occur during a Power-on sequence
and First Seek operation, and
2) Errors which occur after the drive has
become operational.
OH 9 If the error is operational, a Fault Latch
MMDI/ is set. This latch signal prevents any other
3-119 write operation and lights the Fault Indicator.
The PIA-2, which handles faults, stores the
Operational Fault Status from the fault latches
for input to the MPU.
Controlled by the MPU, the fault code display
is driven from the output of PIA-2.
OH 10 Fault Code Card comprises Displays for fault
codes and count. By operating S1 status is
requested to the MPU, which is interrupted.
A MPU-program now displays fault info consisting
of type of faults that have been detected
and the number of times.
By operating S2, all faults are cleared and
OH 9 the drive is brought back into operation.
OH 11 This table shows:
MMDI/2-7
- START-UP AND FIRST SEEK ERRORS
- OPERATIONAL ERRORS INDICATED BY FAULT
LATCH
- OPERATIONAL ERRORD NOT INDICATED BY FAULT
LATCH
- SEEK ERRORS…86…1 …02… …02…
…02… …02…
2803A/ktd
13:2:2 BSP/821102
MMD DISK-DRIVE STRIP-DOWN DE/H/GW
DISK DRIVE Mini This lesson is devoted to:
STRIP-DOWN Module Do a Disk-Drive Strip-Down
Drive
OEM
Manuals
2803A/bel/
13:2:3 BSP/820923
MMD DISK-DRIVE STRIP-DOWN (Pract)
CAMPS
Disk-Drive This lesson is devoted
Strip-Down to: DE/ Mini
Module
Do a Disk-Drive H Drive
Exercise Strip-Down /GW OEM
Manuals
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
2803A/ktd
13:2:4
BSP/821102
CLOCK INDEX/SECTOR HD. SEL.
MACHINE CLOCK The Machine Clock is made in the Servo Clock
Circuits and used by Sector Detection, Index
Detection, and to read PLO circuits. For
controller use, a 9.67 MHz Servo Clock is
generated, too.
OH 1 The sync pulses from the servo data is the
MMDI/ base for the clock pulse (303 KHz).
3-86
Two output pulses are provided. One 100 nSec
pulse is used as the servo clock input to
Phase/Frequency Detector, the other is a
1.15 uSec pulse used as a reference clock
for the Phase/Frequency Detector. The output
of the loop goes to a Voltage Controlled
oscillator (VCO).
The VCO generates a 19.34 MHz signal for
Write Data Circuit. The VCO/2 signal is used
as a Servo Clock for controller (9.67MHz).
The Servo Clock Signal/12 is used for Index
and Sector Circuits.
OH 2 All disk surfaces must have a logical
MMDI/ beginning. This is the point from where
3-89 recordings can take place.
To identify the beginning of a track, the
servo track contains certain info: Quadbits
along with ID-bit and Sync bit.
Sync bit generates the servo clock, and a
missing id-bit generates a missing Clock
Pulse.
Both Servo Clock and Missing Clock Pulses
are sent to a 5-bit Shift Register and are
decoded to identify what the pattern narrates.
If Index enable is decoded, the index flip
flop signals this to the controller.
OH 3 However, the same signals is also sent to
the
MMDI/ sector detection circuitry for a reset.
3-90 A sector is an area on the disk positioned
between two angular positions with respect
to the index.
In order to electrically (and physically)
determine the beginning of a sector, a counter
is incremented by the 806KHz clock pulses
until it reaches its max count, which causes
a sector pulse to be generated.
Next clock pulse resets the counter and the
heads are now in the next sector.
2803A/ktd
13:2:4 BSP/821102
CLOCK INDEX/SECTOR HD. SEL.
OH 4 Before any information can be recorded or
MMDI/ read on disk, the controller must command
3-91 the drive to select the head located over
the disk surface, where the read/write operation
will take place.
OH 5 Head Selection is a matter of various
MMDI/3 signals, High or Low. Three chips are physically
located on the actuator. These chips control
which head to be selected, each chip having
a group to seleclt.
A Head Select Decoder selects which chip
(group of heads) to do the read/write operation.
HIGH/LOW signals ("1" or "0") on SELBIT2
& SELBIT3 enables CHIP1/2/3.
One chip controls a group of ODD/EVEN HEAD.
HIGH/LOW on HDSEL1 enables ODD/EVEN HEAD.
HIGH/LOW on HDSEL2 enables one of the two
heads.
With a head selected, the drive is ready
to perform read/write operations.
OH 6 If a drive malfunction occurs such as loss
MMDI/ of spindle speed or loss of power, the
3-12 actuator will move the head to Safe Area
which is Landing Zone/Parking Zone.
1) Retract operation controlled by MPU-program
(loss of speed or controller shut down
command, loss of +5VDC)
2) Generated by loss of +24V power
Drive malfunctions result in loss of servo
input from the IN & OUT Drive Switchers,
disable In Drive Switcher and current is
supplied to the voice coil to move the heads
outward to retract position and away from
data area.
2803A/bel/
13:2:5 BSP/820923
ADJUSTMENTS (Pract)
CAMPS
Adjustments This lesson is devoted
to:
Tests and Adjustments Mini
Module
that can be performed in GW/Drive
the field. H Field
Test
Unit
Exercise (Procedures to be OEM
Manuals
performed, when there Handouts
is suspicion that the
drive is not functio-
ning properly).
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
2803A/bel/
13:2:6 BSP/820923
TD216 FIELD TEST UNIT
CAMPS
TB216 FTU Introduction to the L/ OH
1
Field Test Unit DE OH
2
2803A/bel/
13:3:1 BSP/820923
TD216 TESTER
CAMPS
TB216 Tester This lesson is devoted
to become fully
acquainted with the
Field Unit Tester
2803A/bel/
13:3:2 BSP/820923
MMD FAULT FINDING
CAMPS
Fault Finding This lesson is devoted
to:
Fault Finding Mini
Module
Procedures in the GW/ Drive
Mini Module Drive. H Field
Test
The Field Test Unit Unit.
is an important part Hands
outs
of these procedures
to unveil errors and
faults.
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
2803A/bel/
13:3:3 BSP/820923
MMD FAULT FINDING
CAMPS
Fault Finding This lesson is devoted
to:
Fault Finding Mini
Module
Procedures in the GW/ Drive
Mini Module Drive. H Field
Test
The Field Test Unit Unit.
is an important part Hands
outs
of these procedures
to unveil errors and
faults.
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
2803A/bel/
13:3:4 BSP/820923
MMD FAULT FINDING
CAMPS
Fault Finding This lesson is devoted
to:
Fault Finding Mini
Module
Procedures in the GW/ Drive
Mini Module Drive. H Field
Test
The Field Test Unit Unit.
is an important part Hands
outs
of these procedures
to unveil errors and
faults.
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
2803A/bel/
13:3:5 BSP/820923
MMD FAULT FINDING
CAMPS
Fault Finding This lesson is devoted
to:
Fault Finding Mini
Module
Procedures in the GW/ Drive
Mini Module Drive. H Field
Test
The Field Test Unit Unit.
is an important part Hands
outs
of these procedures
to unveil errors and
faults.
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
2803A/bel/
13:3:6 BSP/820923
MMD FAULT FINDING
CAMPS
Fault Finding This lesson is devoted
to:
Fault Finding Mini
Module
Procedures in the GW/ Drive
Mini Module Drive. H Field
Test
The Field Test Unit Unit.
is an important part Hands
outs
of these procedures
to unveil errors and
faults.
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
2803A/ktd
13:4:1
BSP/821102
AC DISTR. DC POWER BLOCK DIAGRAM
GENERAL OH 1 The STORAGE MODULE DRIVE comprises several
SMDI/1-4 functions, some of these being logic ones.
All circuits and electromechanical devices
are necessary for recording data on and recovering
data from the surface of the disks in the
disk pack.
All the functions performed by the drive
is done under the direction of the controller.
OH 2 The Power System Function supplies the
SMDI/3-1 power necessary to all drive functions to
perform well. The drive power supply receives
its input from the Site Main Power Source.
Power Systems Functions describes the power
distribution to circuits in the drive necessary
for operation.
The power supply produces AC power as well
as DC power.
OH 3 With the Drive Power Plug P1 plugged in the
SMDI/3-3 AC-Power Circuit Breaker, A1CB1 distributes
AC-power to the Elapsed Time Meter M1, the
Rear Door Fans, the Blower Motor, and the
Drive Motor.
The Power Supply Circuit Breaker A1CB2 supplies
AC-power to the Transformer T1. Both Circuit
Breakers serve as overload protection devices,
too.
2803A/ktd
13:4:1 BSP/821102
AC DISTR. DC POWER BLOCK DIAGRAM
OH 4 The AC Power System shows the circuit which
x REF 302 comprises the Transformer T1 from which 42VAC,
9.2VAC, and 20VAC is derived. Circuit Breakers
CB1 and CB2 are also shown.
OH 5 The Assy A1 shows the positions of Potmeters
x REF 322 in the circuit where +/-5V Adjustment are
made.
OH 6 The Assy A1 shows the positions of Fuses
x REF 323 F1 and F2 (to protect the +/-20V circuitry)
and Fuses F3 and F4 (to protect +/-42V circuitry)
EX 1A The procedure of checking/adjusting plus
and
EX 1B minus 5volt supplies is briefly explained.
This will be the intro to a Groupwork coming
up.
2803A/ktd
13:4:2 BSP/821102
SMD POWER-UP SEQUENCE LOAD SEEK, SERVO L/DE/GW
POWER-ON OH 1 In order to initiate a power on sequence,
SMDI/3-5 power distribution must be complete. The
sequence itself is the chain of events which
allow the drive motor to start and the heads
to load.
First: The brakes are released.
Second: Power is applied to the drive motor.
Third: When spindle speed is OK, the heads
are loaded onto the disk pack.
No power on sequence will take place, if
pack cover (access to disk pack) is not closed
(S3). It takes approx. 20 seconds for the
drive motor to get sufficiently up to speed
(about 3000
rpm).
LOAD SEEK After a delay of 10 seconds, the head loads,
which means they move from retract position
over the disk surface. The Power Amp. outputs
a current to flow in the voice coil, and
the carriage and coil assy are driven forward,
loading the heads.
HEAD LOADING OH 2 Head Loading will take place when Disk Pack
SMDI/3-B rotation has reached 3000 rpm. That implies
that the spinning of the disk creates a cushion
of air upon which the heads will fly.
During the Head Load, the Heads move forward
with the Head Load Springs riding on the
Cam Tower Ramps. This prevents the heads
from banging into the disks during a head
load.
As the heads move out over the disk surfaces,
the head load springs ride off the cam tower
ramps. Then the heads will get close to the
disk surfaces until the force of head load
springs has reached an equilibrium with the
force of the opposing air.
If rotation speed drops below 3000 rpm, the
head load springs forces the heads down to
the disk surfaces because air cushion pressure
decreases.
Sufficient loss of speed causes the heads
to stop flying, and contact with disk surfaces
occur. This is called a HEAD CRASH and can
cause damage to both disk surfaces and heads.
2803A/ktd
13:4:2 BSP/821102
SMD POWER-UP SEQUENCE LOAD SEEK, SERVO L/DE/GW
OH 3 The Load Seek will be under Coarse Control
SMDI/3-50 until the head is near Track [. When the
heads approach Cylinder [, a Load Seek Fine
Control will land the heads upon the desired
track.
If for any reason it is detected that heads
have not left the Head Loading Zone whithin
350 mS after Load Latch is set, the RTZ latch
sets and the head unloads to the fully retracted
position.
MECHANICAL OH 4 This gives an impression of location of
FUNCTIONS SMDI/3-8 Disk Pack Rotation Mechanisms.
SERVO SYSTEM OH 5 Before any Read/Write operation can be
SMDI/ performed, the Read/Write Heads must have
3-28 been moved to the desired position. This
is done by the servo circuits.
A comparation of the desired future position
of the heads to the present one will result
in a controlled movement, while the servo
system monitors a position control signal,
which is proportional to the difference between
the two positions.
The position converter provides a Coarse
Seek Signal, the amplitude of which is proportional
to to tracks to go.
The Desired Velocity Function Generator outputs
the analog representation of the desired
Volocity Curve. This makes the fastest seek
with controlled deceleration to prevent overshoot.
2803A/ktd
13:4:3
BSP/821102
SMD SERVO SYSTEM & DISK L/DE/GW
DATA STORAGE OH 1 The Data Storage Medium is a 5 disk Disk-Pack
MEDIUM SMDI/1-3 which is portable and interchangeable. There
are six usable surfaces, each coated with
Iron Oxide Particles which can be magnetized
in a flux field.
5 of these surfaces can be used for Data
Storage. They are, therefore, referred to
as Data Surfaces.
The last one comprises prerecorded information
used for position info and various timing
signals. This surface is referred to as Servo
Surface.
SERVO DISK OH 2 The information on servo surface is read
by
INFO SMDI/ the Servo head. The Position Feedback Circuits
generates signals used by position control
circuits to control the positioning of the
heads.
DIBITS OH 2 The servo information is recorded on disk
as so to speek magnet bars (Magnetized Iron
Oxide Particles). This forms a specific pattern
of flux reversals referred to as DIBITs.
They consist of two types:
Positive and Negative Dibits.
Waveform:
POS DIBIT: Leading pulse POS and trailing
pulse NEG
NEG DIBIT: Leading pulse NEG and trailing
pulse POS
SERVO DISK OH 3 A servo disk contains dibit patterns all
SMDI/ around the disk except in the Head Loading
3-32 Zone.
There is a servo zone consiting of:
823 servo tracks recorded as alternate Positive-ODD
and Negative-EVEN dibit tracks, an Outer
Guard band Zone consisting of 24 Positive
- ODD Dibit Tracks and
an Inner Guard Band consisting of 36 Negative
- EVEN Dibit Tracks.
2803A/ktd
13:4:3 BSP/821102
SMD SERVO SYSTEM & DISK L/DE/GW
All tracks are recorded adjacant to each
other.
The Inner Guard band is also called Forward
End of Travel.
The Outer Guard Band is also called Reverse
End of Travel.
POSITION OH 4 In order to position the heads exactly on
SMDI/ the desired cylinder, the position feedback
3-34 circuits use the Dibit signal from the Servo
Head to generate a feedback signal for the
Position Control Circuits.
The circuits sense the type of Dibit, if
any, to determine whether the Servo Head
is in one of the Guard Bands
(Inner GB: NEG-EVEN/OUTER GB: POS-ODD)
or it is in the Servo Zone.
If the Servo Head is in one of the Guard
Bands (End of Travel), signals to position
control will return the Servo Head to the
Servo Zone.
OH 4 If the servo head is in the Servo Zone, the
detected Dibit Signals will be analyzed for
Amplitude of ODD/EVEN Dibit signal for Fine
Position Control and any Cylinder Crossing
will be detected and counted.
TRACK SERVO OH 5 The Servo Preamp Output shows the pattern
of
PREAMP SMDI/ the detected Dibit Signals during Cylinder
3-35 Crossings by the Servo Head. Also shown is
the output, when Servo Head is centered over
Track.
TRACK SERVO OH 6 This shows the Track Servo Amplifier
SIGNAL SMD/ Circuit and the signal obtained during
AMPLIFIER 3-36 Cylinder Crossing. Note Motion of head is
exaggerated as well as waveforms illustrated
are ideallized.
ODD/EVEN OH 7 The Odd/Even Dibit Clock Logic used for End
DIBITS CLOCK SMD/3- of Travel Detection and for the machine clock
(and the Index detection) are shown together
with Clock Timing.
2803A/ktd
13:4:4 BSP/821102
DIRECT SEEK, RTZ SEEK L/DE/GW
CYLINDER OH 1 The Cylinder Concept is the illustration
of
CONCEPT SMDI/ an imaginary cylinder. All heads including
3-33 the Servo Head is aligned vertically on the
actuator.
Therefore, when the Servo Head is positioned
over a certain track on the servo surface,
all Data Heads are also positioned over the
same Data Track on their Data Surface.
ACTUATOR OH 2 When the Servo Head moves to a desired track
COMPONENTS SMDI/ all heads move at the same time as they are
3-11 all attached to the carriage.
DIRECT SEEK OH 2A A direct seek is a controlled seek from One
SMDI/ Track to Another one. Velocity Feed Back
Circuits control the Volocity of the Carriage
in order to have the shortest seek time without
having any overshoot.
A Velocity Transducer within the magnet senses
the velocity from induced EMF in the coil
and the amplitude of the signal varies with
the speed of the Carriage.
A direct seek is divided into two phases:
A Coarse Seek and a Fine Seek.
The Coarse phase is a seek over all the tracks
to go but the last half track of the seek.
Then the servo system is in Fine mode during
the last half track and while the heads are
tracking over the desired cylinder.
COARSE SEEK OH 3 The Coarse seek is controlled by the Coarse
CONTROL SMDI/ Seek Control Circuits.
The distance between destination cylinder
and the present one is calculated and loaded
into the difference counter, where it will
be decremented at cylinder crossings.
The output from the D/A Converter is info
on a Rev/Fwd Seek and desired seek velocity.
The Velocity Integrator Signal varies in
amplitude with carriage speed and is opposite
in polarity to the desired velocity signal
thus controlling carriage speed to ensure
minimum seek time without overshooting the
destination cylinder.
2803A/ktd
13:4:4 BSP/821102
DIRECT SEEK, RTZ SEEK L/DE/GW
FINE SEEK OH 4 The Coarse to Fine switchover takes place
CONTROL SMDI/ when the difference counter indicates one
cylincer to go. Then the Fine Latch is set
and Coarse Control is disabled.
The Fine Postion signal is the sum of Fine
Position Analog Signal and Velocity Feedback.
Fine Position Analog Signal varies with distance
to the destination cylinder centerline, and
Velocity Signal varies with carriage speed.
The sum of these two signals are of opposite
polarity and since the Velociy signal is
greater than the Fine Position Analog Signal,
the carriage must decelerate.
ON CYLINDER OH 5 When the heads are centered over and
DETECTION SMDI/ tracking the destination cylinder both the
3-19 Fine Pos. Analog Signal and Velocity Signal
are Zero. This implies an On Cylinder condition.
The On Cylinder Detection Circuit enables
when the Fine Latch is set, and when Fine
Pos. Analog Signal is small enough, at time
delay of 1.75 MS is triggered to allow heads
to settle. At Run-out, the On Cylinder Condition
occurs.
The Servo System will now have to monitor
that the heads do not drift too much off
center line.
If the heads should drift off center line,
the servo signal will decrease or increase
slightly from zero.
This is fed back to Fine Pos Signal, and
the polarity of this signal makes the Amp
generate the proper voice coil current to
crive the hads back on center line.
RETURN TO OH 6 If a RTZ-seek condition arises, the
ZERO SEEK SMDT/3-50 controller commands the drive to seek to
cylinder [.
This sets the RTZ-latch, which causes the
carriage to move towards the Outer Gaurd
Band.
When the Carriage moves past cylinder [,
it enters the Reverse EOT area where Dibits
are only Positive-ODD. The Position feedback
circuits disable the RTZ-latch and enable
the Load-latch, which makes the Carriage
move to track [ like during a load seek.
2803A/ktd
13:4:5 BSP/821102
READ/WRITE OPERATION L/DE/GW
READ/WRITE
OPERATION OH 1 Information is recorded on and recovered
SMDI/3-57 from the disk by the Read/Write Heads. There
are five Read/Write Heads, each having their
own data recording surface.
After having selected the Head over the disk
surface where data are to be read or written,
Read/Write operations can be performed.
OH 2 Data is written to the surface during disk
SMDI/3-58 motion by reversing the current through the
windings of the recording Head.
This causes a flux field in the head gap
to magnitize the magnetic coating beneath
the head.
Change in polarity changes the direction
of the flux field. This flux change defines
a bit.
Data is read from the surface during disk
motion. The magnetic coating induces a flux
flow in the coil which generates a current
in the winding of the Read Head.
Each flux reversal in the magnetic surface
causes a current Polarity change which defines
a bit.
READ/WRITE OH 3 When a head has been selected and the head
CIRCUITS SMDT/3-63 is on the desired cylinder on the proper
place, a Read/Write operation can be performed.
During a write operation the write circuits
receive data from the Controller and records
it on the data surface.
During a Read operation the Read Circuits
recover data from the disk and transfer it
to the controller.
…86…1 …02… …02… …02… …02… …02…
2803A/ktd
13:4:5 BSP/821102
READ/WRITE OPERATION L/DE/GW
WRITE OH 4 Write operations are performed by the Write
CIRCUITS SMDI/3-63 Circuits.
The Converter receives data from the Controller
and converts them into MFM data and compensate
for problems caused by variations in frequency.
The WRT Driver Circuits receive the compensated
data, and underwrite current control the
data are written onto the disk.
FLUX RECORD- OH5 The MFM WRITE flux change defines the bits
ING SMDI/3-64 recorded on the disk. The read back signal
is then processed, and a Read Data Output
is detected.
READ OH6 Read Operations are performed by the Read
CIRCUITS SMDI/3 circuits.
The analog RD Data Detection Circuit Processes
the sensed signal from the RD/WRT Head and
forward the Analog data to the A/D-converter
to be converted into Digital MPM Read Data.
The RD PLO and data separator converts MFM-data
into NRZ-data.
2803A/ktd
13:4:5 BSP/821102
READ/WRITE OPERATION L/DE/GW
FAULT OH7 Shows the position of Maintenance
LOGIC switches and indicators.
OH8 Gives the description of Maintenance switches
and indicators.
OH9 There are two categories of errors:
SMDI/3-76
1) Errors which are indicated by a Fault
Latch.
2) Errors which are not indicated by a Fault
Latch.
When ever an error associated with a Fault
Indicator occurs, the Fault Latch is set
together with the individual Fault Latch
and the indicator lights.
This prevents the drive from further operations
being performed until the error is corrected
and the Fault Latch reset.
This can be done by either:
1) Fault Switch on operators panel
2) Controller Fault Clear from Controller
3) Maintenance Fault Clear Switch on Fault
Card
4) Powering down the Unit
If Spindel speed drops below 3000 RPM, the
WRT circuits are disabled, and the write
Protect signal is sent to the Controller.
This also result in a emergency retract of
the heads.
2803A/ktd
13:4:5 BSP/821102
READ/WRITE OPERATION L/DE/GW
EMERGENCY OH10 If an unsafe condition (Loss of spindel speed
RETRACT SMDI/3-6 or Voltage Fault) occurs, the Emergency Retract
Circuits provide the function of retracting
the heads from the Disk Pack Area.
This is done by applying Emergency Retract
Power to the voice coil which causes the
heads to retract. That is done when Emergency
Retract Relay returns to
NC position.
The Darlington coupled transistors Q5 prevents
the carriage from slamming into the reverse
stop during an Emergency Retract situation.
2803A/ktd
13:4:6 BSP/821102
INDEX/SECT. HEAD SEL. INTR. AD L/DE/GW
INDEX OH 1 A Read/Write operation cannot be performed
DETECTION SMDI/3-59 until the head is over the desired part of
the data track (on the proper cylinder).
An Index signal is used to show the logical
beginning of a track.
The Index Detection circuit senses the pattern
of dibits on the servo tracks.
A pattern of missing dibits is detected and
handled in the Index Shift Reg.
The pattern is decoded by the Index decoder,
and an Index pulse is outputted to the Controller
and the sector detection circuitry.
SECTOR OH2 The sector detection circuits monitor sector
DETECTION SMDI/3-61 pulses to determine the angular position
of the heads with respect to Index/beginning
of the tracks.
The sector pulses are generated by the Sector
Counter, which is incremented by the 806
KHZ clockpulses until it reaches its max.
value; then a sector pulse is outputted,
and the counter is reset to a preset value
and again incremented by the clock pulses.
The clockpulse is derived from servo track
Dibit signals.…86…1 …02… …02… …02…
…02… …02…
2803A/ktd
13:4:6 BSP/821102
INDEX/SECT. HEAD SEL. INTR. AD L/DE/GW
HEAD OH3 The drive has five Read/Write Heads but only
SELECTION SHMI/3-59 one can be selected to perform Read/Write
operation at a time.
Therefore the controller must command the
drive to select the head over the surface
where the data is to be read or written.
A combination of three bus bits decides which
head to do the performance. After being decoded
the head is enabled and can perform Read/Write
operations.
If more than one head is selected a fault
is indicated, which prevents further drive
performance.
OH4 This shows a Head Alignment setup.
OH5 This is the procedure to be followed during
a Head Alignment check and adjustment Procedure.
OH6 This shows the location of a +/- 5V adjustment.
&
OH6A Power Supply is checked at GND & 5V fas toms
on Logic Chasis Backpanel.
OH7 This shows locations for Head Arm Alignment
(Note Alignment tool and see insert).
OH8 This shows the location for Velocity Gain
Adjustment.
2803A/bel/
13:5:1 BSP/820923
SMD ADT/FAULT FINDING
CAMPS
Storage Module This lesson is devoted
Drive to: Storage
Adjustment/ Various Adjustments GW/ Module
Faultfinding on the SMD-Drive S/ Drive
H OEM
Manuals
Handouts
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
Exercises Finding Faults on the GW/
SMD-Drive S/
S S
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
2803A/bel/
13:5:2 BSP/820923
SMD ADT/FAULT FINDING
CAMPS
Storage Module This lesson is devoted
Drive to: Storage
Adjustment/ Various Adjustments GW/ Module
Faultfinding on the SMD-Drive S/ Drive
H OEM
Manuals
Handouts
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
Exercises Finding Faults on the GW/
SMD-Drive S/
S S
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
2803A/bel/
13:5:3 BSP/820923
SMD ADT/FAULT FINDING
CAMPS
Storage Module This lesson is devoted
Drive to: Storage
Adjustment/ Various Adjustments GW/ Module
Faultfinding on the SMD-Drive S/ Drive
H OEM
Manuals
Handouts
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
Exercises Finding Faults on the GW/
SMD-Drive S/
S S
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
2803A/bel/
13:5:4 BSP/820923
SMD ADT/FAULT FINDING
CAMPS
Storage Module This lesson is devoted
Drive to: Storage
Adjustment/ Various Adjustments GW/ Module
Faultfinding on the SMD-Drive S/ Drive
H OEM
Manuals
Handouts
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
Exercises Finding Faults on the GW/
SMD-Drive S/
S S
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
2803A/bel/
13:5:5 BSP/820923
REVISION
CAMPS
Revision - Fault- This lesson is devoted
finding to: I/
Both Disks Revision on Fault- DI/
finding on both the DE
Mini Module Drive
and the
Storage Module Drive.
Hard to understand
topics.
Refreshing Topics.
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
2803A/bel/
13:5:6 BSP/820923
REVISION (cont'd)
CAMPS
Revision - Fault- This lesson is devoted
finding to: I/
Both Disks Revision on Fault- DI/
finding on both the DE
Mini Module Drive
and the
Storage Module Drive.
Hard to understand
topics.
Refreshing Topics.
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
2803A/bel
BSP/821006
MMD AC DISTRIBUTION, DC POWER BLOCK DIAGRAM
What is the purpose of the Circuit Breaker CB1?
What is the purpose of Fuses F1 - F5 ?
What is the purpose of the Thermostat S1 ?
What is the purpose of the Line Filters ?
Where does the DC Voltage Regulator Board
receive its power from ?
2803A/bel
BSP/821006
MMD POWER-UP SEQUENCE, FIRST SEEK
What is the most basic performance to do to initialize
a power-up ?
The power-up sequence is under the control of an initialization
program under the diretion of a special chip. What
is the chip called ?
The power-on sequence has been initialized and a fault
(code 06) is detected, which prevents further power-up
actions. What has failed ?
At what speed does the spindel motor revolve ?
What happens if the Drive Motor overheats ?
2803A/bel
BSP/821006
MMD SERVO DISK SERVO CIRCUITS, "QUADBITS"
What is the purpose of the Mini Module Drive Servo
Disk ?
What is the purpose of Quadbits ?
What is a Landing Zone and what is a Guard Band ?
How many Landing Zones does e̲a̲c̲h̲ ̲D̲i̲s̲k̲ ̲S̲u̲r̲f̲a̲c̲e̲ contain
?
Make a sketch of a 80MB Disk Format and Head Configuration.
2803A/bel
BSP/821006
MMD SERVO SYSTEM, DIRECT SEEK, RTN T.ZERO SEEK
What is the purpose of the Peak Detectors ?
What does "on track" condition mean ?
F̲r̲o̲m̲ what position t̲o̲ what position are the heads moved
during Power-up Seek ?
During a normal seek the head are moved from a High-numbered
Track to a Lower-numbered Track. Which movement direction
is that ? (Justify your answer).
Make a sketch of a Servo Track output.
2803A/bel
BSP/821006
MMD READ/WRITE OPERATION. FAULT LOGIC.
How many recording heads does a MMD have ?
How is Data written to a Data Recording Surface ?
How is data read from a surface ?
What is the purpose of Analog to Digital Converter
?
In what way is MMD Diagnostic Faults Displayed?
2803A/bel
BSP/821006
MMD MACHINE CLOCK.INDEX/SECTOR.HEAD SELECT.
What is the purpose of the Machine Clock ?
What does an index-pulse indicate ?
What is a sector ?
How is a Head selected ?
Where will the heads be positioned at the end of an
emergency Retract ?
2803A/bel
BSP/821006
SMD AC DISTRIBUTION. DC POWER BLOCK DIAGRAM.
What is the purpose of the Power Supply Circuit Breaker
A1CB2 ?
What is the purpose of the AC-Power circuit Breaker
A1CB1 ?
How is the 5V Power Supply protected ?
How is the 12V Power Supply protected ?
What is the function of the time meter M1 ?
2803A/bel
BSP/821006
SMD POWER-UP SEQ. LOAD SEEK. SERVO SYS.
You have just mounted a Disk-Pack and you press the
START-Switch .... and nothing happens, what could be
wrong ?
What prevents the heads from banging into the Disk
during a headload ?
Why are the heads not riding o̲n̲ the surface of the
spinning Disks ?
What is a Head Crash ?
When is a Load Seek initialized, and what is a loadseek
?
2803A/bel
BSP/821006
SMD SERVO SYSTEM. SERVO DISK.
What is the purpose of the Storage Module Drive Servo
Disk ?
What is the purpose of Dibits ?
Make a sketch of a Servo Track Output.
What is the purpose of the inner Guard Band ? and the
outer Guard Band ?
Make a sketch of a 80MB Disk Format and Head Configuration.
2803A/bel
BSP/821006
SMD DIRECT SEEK. RETURN TO ZERO SEEK.
What does "Cylinder Concept" imply ?
Why is it necessary to have at coarse control and a
fine control during a direct seek ?
When does coarse to fine switching take place?
How are the heads prevented to drift off centerline
?
Where are the heads positioned after a RTZ-Seek ?
2803A/bel
BSP/821006
SMD READ/WRITE OPERATION. FAULT LOGIC.
Which heads in the SMD do have a recording function
? (feel free to make a sketch).
Draw a sketch of a Write Current.
Draw a sketch of a Read Back Signal.
The Fault latch has been set and the Fault indicator
on operator panel is lit.
How can you find out what the error is ?
Where are the heads positioned after an emergency retract
?
2803A/bel
BSP/821006
SMD INDEX/SECTOR.HEAD SELECT. INTRO T.ADJSTM.
What is the purpose of an index signal ?
What does the system (SMD) use a sector signal to ?
What happens if more than one head is selected?
Where are power supplies checked on the SMD ?
When a 5Volts adjustment is in progress and the Locig
Chasis is raised, the Drive should not be operated
for an extended period. Why is that ?
…02…BSP/831121…02……02…
RST LAB EXERCISE WEEK 13
…02……02…CAMPS
S̲T̲O̲R̲A̲G̲E̲ ̲M̲O̲D̲U̲L̲E̲ ̲D̲R̲I̲V̲E̲
Perform plus & minus 5 volt adjustment (2 card power
supply according to the SMD maintenance manual.
Did you obtain the same +̲ 5 V level specs as outlined
in the manual?
What happened when the output was not within the specs?
Perform velocity gain adjustment (80MB) according to
the SMD maintenance manual.
Perform Speed Transducer Adjustment according to SMD
maintenance manual.
Calculate the SECTOR SELECT SWITCH SETTINGS for the
sector switches located on logic card A2 B08.
Do the switch settings calculated match with the actual
switch settings.
Connect SMD to CAMPS System as unit 2 in daisy chain
according to SMD maintenance manual.
…02…BSP/831121…02……02…
RST LAB EXERCISE WEEK 13
…02……02…CAMPS
M̲I̲N̲I̲ ̲M̲O̲D̲U̲L̲E̲ ̲D̲R̲I̲V̲E̲
Perform:
Plus & Minus 5 Volts Adj. (2-13)
Servo Gain Adj. (2-16)
Velocity Overshoot Adj. (2-16)
Pos Null Adj. (2-19)
Perform:
Power System Check (2-22)
Servo System Check (2-24)
Read/Write Check (2-34)
Misc/Check (2-39)
All of the above Adjustments and checks are thoroughly
described in the MMD Maintenance Manual (x-xx) are
referring to this manual.
Good Luck!
