Page 1
301462·002
PERKIN-ELMER
Memory
Products
Division
SUPER SERIES
(SF
AND
ST)
MAGNETIC DISK
DRIVE
OPERATION
AND
MAINTENANCE
VOLUME
1
Page 2
Pr8nted
In
U.S.A.
PERKIN-ELMER
Memory Products Division
SUPER SERIES
(SF
AND
ST)
MAGNETIC
DISK
DRIVE
OPERATION
AND
MAINTENANCE
VOLUME
1
Page 3
Revision
Letter
Prelim.
A
Super Series Disk Drive
Manual 301462
Revision Level
Description
Released
to
cover 1500 and 2400 rpm, 2200
BPI
machines only. Though
listed in Appendix B Index, Dwgs. 301422 (Data Control -
MFM),
301632
(DCB), 301650 (Spindle Drive
Limiter
PWB
and Schematic), and 301653
(High I mpedance Spindle Switch
PWB)
were
not
available
for
inclusion in the
manual.
Though listed in Appendix C I ndex, Schematics 301691
(I
nterconnection
Diagram), 301423 (Data Control -
MFM),
301633 (DCB), 301637 (EIB),
301654 (High Impedance Spindle Switch), and 301063
(I/O
Connector-·
D31/33) were
not
available
for
inclusion in the manual.
The manual
was
written
to
cover high-impedance
DC
spindle drive motors;
therefore,
an
Addendum
was
included
to
cover early produced units
with
low
impedance motors.
Though position, number, and
title
were indicated, photographs
for
the fol-
lowing illustrations were
not
available.
Figure
Title
3-3
Series T Cartridge Loading
5-3
Front-Load
with
Cover Removed
5-4
T op-Load
with
Cover Removed
5-5
Assy.
Identification -Bottom
View
5-7
Simplified
Front
View
5-10
Power Supply Assy.
Appendix A - A Master Spares List
was
not
available.
This
release
also covered 1500 and
2400
rpm,
2200
BPI
machines
only;
how-
ever all drawings misssing
from
Appendix
B in the Preliminay
Release
were
now
included except Dwg. 301422, Data Control
MFM,
which
was
for
4400
BPI
operation.
All
schematics missing
from
Appendix
C in the Preliminary
Release
were
included
with
the exception
of
Data
Control
M FM Schematic 301423.
SECTION 3 - OPERATION
The photograph
for
Figure 3-3
was
included.
SECTION 4 -
THEORY
OF OPERATION
Major
signal lines were added
to
Figure 4-9 Block Diagram.
Updated Descriptions and new simplified diagrams were added
to
the
DCB
writeup
under para. 4.5, Logic Board
Circuit
Analysis. Other new paragraphs
were also added under para. 4.5 explaining Speed Dection and
AC/DC
loss
Recovery logic.
Minor
errors in technical writeups were corrected.
ii
Date
4/76
5/76
Page 4
Revision
B
SUPER SERIES
DISK
DRIVE
MANUAL
301462
REVISION
LEVE
L
RECORD
OF
REVISIONS
Description
SECTION 5 -
MAINTENANCE
Photographs and art
work
necessary
to
complete 5-3, 5-4, 5-5,
5-7, and
5-10 were included.
Under paragraph 5.5,
ADJUSTMENT
AND
CALIBRATION
PROCEDURES, a
CAUTION
for
Adjustment
of
the
SVA
with
P15
removed
was
added.
Appendix
A - A Master Spares List
was
not
available.
This release constituted
the
full
release
of
the Super Series manual and
included all
information
necessary
for
4400
BPI
operation. Dwg.
301422
for
the Data
Control -MFM
PWB
was
not
available
for
Appendix
B,
but
its schematic, Dwg.
301423
was
added
to
Appendix
C
SECTION
2-
Figure
2-1
was
changed
to
coordinate
with
newly created Table
2-1
in
order
to
provide the user
with
more
information
on unpacking
or
reshipping machines.
SECTION
4-
Writeups were added
as
required
to
cover
the
Data Control
MFM
PWB
which also required
two
new illustrations: one
for
Read; one
for
Write.
SECTION
5-
Writeups were added
as
required
to
cover the Data Control
MFM
PWB
which also revised Detent Waveform Figures 5-33 and 5-34.
Throughout
Section 5, grid coordinates were added
to
test
point
references
as
an
assist
for
technicians in
the
field. Table 5-2
was
expanded
to
include new accessories and maintenance aids.
A
CAUTION
was
added against removing Positioner
head
load cams
or
the head
mounting
block
during removal and replacement. The
CAUTION
was
also applied
to
the Positioner
illustration
on the IPB.
The
SVA
Adjustment
procedure
was
completely revised and
rewritten
for
the field
to
reflect improved procedures developed
for
the lab
by
Perkin-Elmer Engineering (paragraphs 5.5.5 through 5.5.8).
SECTION
6-
This section
was
completely
revised and reprepared.
APPEND
IX
A - Master Spares List completed and included.
iii
Date
7/76
Page 5
Revision
Letter
C
SUPER
SERIES
DISKDRIVE
MANUAL
301462
REVISION
LEVEL
Description
SECTION 1 -
GENERAL
DESCRIPTION
Revised
Write Protect
and
Write I
nhibit
Circuitry descriptions
(para.
1.1.1).
SECTION 4 -
THEORY
OF
OPERATION
Updated Safety Features (para. 4.3.2).
SECTION 5 - MAINTENANCE
Revised
SVA Adjustment procedure
and
Operational Checks
(paras.
5.5.5
and
5.5.6). Added Fine Offset
and
Access
Time Adjustments
(paras.
5.5.5.4
and
5.5.5.5).
Revised
Temp. Compensation Check* (para. 5.5.7)
and
added
Ready
Inhibit
Check (para. 5.5.8).
Changed
VCO Clock
to
10.5 MHz
on
MFM
PWB
(5.5.13.1).
Figure 5-32: Added Thermistor callout. Added new Figures 5-33
and
5-34
for
100
and
200
TPI
Detent waveforms. Added Figure 5-35, Fine Offset
Adjustment.
*
Chart
of
Figure 5-36, Temp. Compensation Voltage Chart, deleted. Data
now in new Table 5-4.
APPENDIX B - ENGINEERING
DWGS.
AND
MATL.
LISTS
Updated Dwgs.: 400000, Disk Drive, 100/200 TPI
ST
(A - B); 301457,
Detent
Amplifier
PWB
(B
- C); 301483,
SVA
(E
- G); 301636, E I B
(A -B)
301650, Spindle Drive
Limiter
PWB
and
Schematic (A - B); 301206,
DEB (D - F); 301632,
DCB
(C
- E),
and
301047, Line Terminator
PWB,
031/33
Female (A - B). Dwg.
for
MFM
PWB
(301422A) added.
All
drawings re-indexed
to
numerical order,
and
dash
versions
of
material
lists added for:
CIB (301174), DEB (301206),
I/O
Connector
PWB
(301291),
DIB (VFO 301321),
DCB
(301633),
and
MFM
PWB
(301422).
APPENDIX C - SCHEMATICS
Updated Dwgs: 301458, Detent
Amplifier
(A - B); 301484,
SVA
(D - F);
301637, EIB (A - B); 301207, DEB (D - E),
and
301633,
DCB
(B
- D).
APPENDIX D -
IPB
Figure
D-11
(P.
D-29): Item 46 added
to
callouts.
Page
D-31, Item 42,
quantity changed from
31
to
29.
iv
Date
9/76
Page 6
Revision
Letter
D
SUPER SERIES DISK
DRIVE
MANUAL
301462
REVISION
LEVEL
Description
Revision D constitutes a major revision
of
the SF-ST manual due
to
Engineering redesign which replaced
four
PWB's
and
modified the
MFM
PWB
as
described under Appendices
Band
C below. This manual,
which incorporates these
changes,
has
been
reassigned
the
dash
number -002.
All
data pertinent
to
the
four
replaced
PWB's
and
presented in Revisions
A,
B,
and C
of
this manual,
has
been
assigned
dash
number -001 and
is
contained in Appendix
E.
Section 2: Figure 2 and Table 2 - Added shroud.
Paragraphs 2.4.2 through 2.4.7.4 revised and rewritten.
Section 4: Paragraphs 4.5.1.5, 4.5.9.2, 4.5.10,
and
4.5.12 rewritten
to
accomodatenew PW8's.
Section
5: Paragraph 5.3.6.3: procedure
for
screw removal added.
Paragraph 5.5.3 rewritten
to
accomodate new
PWB's.
Section 6: Completely revised
to
include IC reference data.
Appendix
A:
Page
A-1: Item 6 changed.
Page
A-2: Item 2
Next
Assembly changed.
Appendix
B:
Commutator
PWB
301170 replaced by 301920.
I/O
Connector D-40
PWB
301453 replaced by 301936.
Spindle
Drive
Limiter
+5V
Drive
PWB
301650 replaced by 301794.
Spindle Switch
PW8
301653 replaced by 301789.
Updated: Disc Drive, ST, 400000 (8-C); Disk Drive, SF,
400001
(8-C); Line Terminator D31/33 Female 301047 (8-C);
Line Terminator D31/33 Male
301055 (8-C); CIB 301174 (8-C);
DEB
301206 (F-G);
I/O
301291
(A-A
1);
DIB-VFO 301320 (C-D) ;
PS
301361 (8-C); MFM-DCB 301422 (A-C);
SVA
301483 (G-H);
DCB 301632 (E-E1);
EI8
301636 (B-E); SLB 301687 (8-C).
Appendix
C:
I/O
D40 Schematic 301454 replaced by 301937.
Spindle Switch Schematic 301654 replaced by 301790.
Updated: CIB 301175 (C-D);
I/O
Connector 301292
(A-A1);
Power Supply 301361 (8-C); MFM Data Control-2 301423 (A-B);
SVA
301484 (F-G);
DCB
301633 (D-D1); EIB 301637 (8-C).
Appendix D: Figure D-4
Item 14, Home Switch changed.
Page"D-9,
Item 14 changed.
Page
D-18: Items 15 and
16
changed (figure D-7 callouts
changed
to
agree).
Page
D-6: Item
11
changed.
Page
D-12: Items 2, 3, and 7 changed.
Appendix
E:
Added
to
cover information applicable
to
four
replaced
PW8's (ref. Appendices 8
and
C above). Updated:
Commutator
PWB
301170 (8 - C1); Spindle Switch
PW8
301653 (A - A 1).
v
Date
3/77
Page 7
Super Series Disk Drive
Manual
301462
Revision Level
Revision
Letter
E SECTION 4
Paragraph 4.5.13: Added explanation
cation
SECTION 5
Air
filter
Page
Pages
WARNING added
Page
5-80, para. 5.5.13.4: Added 20 megabyte emergency retract check.
Also added Figure 5-44, "Two-speed Emergency Retract" (ACN 41877).
Appendix B: Updated: Disk Drive,
400001 (C-D);
DEB, 301206 (G-H); Power Supply, 301361 (C-D); MFM, 301422 (C-C1);
EIB, 301636
Spindle
I/O
and
Added: Emergency Retract,
Description
of
Emergency Retract
for
20 megabyte drives (ACN 41877).
CAUTION added
5-70: Dimension in Note changed
5-71
through 5-75 revised and rewritten (ACN 3377).
to
paras.
to
pp.
5.4.3.16
5-17,5-28,5-29,
to
"O.020-inch" (ACN 52077).
and
5.5.114 (ACN 41377).
ST, 400000 (C-E); Disk Drive, SF,
I/O
Connector
031/33,301062
(E-F); SLB, 301687 (C-B); Spindle Switch, 301789 (B-B1);
Limiter/5V
PWB
D40, 301936 (A-B).
Drive, 301794 (A-B
1)
; Commutator, 301920 (A-B);
302064.
(B-C);
and
C1
PWB
modifi-
5-51
(ACN 4877).
B,
301174 (C-C1);
Date
6/77
F
Appendix C: Updated: DEB, 301207 (E-F); Power Supply, 301361 (C-D),
and DCB, 301633 (D1-D2).
Added: Emergency Retract
Appendix E: Deleted
Appendix B: Updated: MFM Data
Amplifier,
Commutator Board
Retract,
Appendix
Retract,
301483 (H-J); Electronics Interconnect, 301636 (F-G);
PWB
302064 (X1-A).
C:
Updated: MFM Data Control-2, 301423 (B-C); Emergency
302065 (X1-A).
302065.
Pages
and
E-29, E-30, E-31, E-32, E-33,
Control, 301422 (C1-D);
and
Servo
E-34.
Schematic, 301920 (B1-C1); Emergency
vi
7/77
Page 8
Revision
Level
G SECTION 4
Super Series DiskDrive
Manual 301462-002
Revision Level
Description
Paragraph 4.6.2, Schematic Designators, deleted.
All
subsequent paragraphs
renumbered and changed
to
call/out
PWB's
by
abbreviated
names.
SECTION 5
Paragraphs 5.3.3,
READ/WRITE
HEAD
INSPECTION
AND
CLEANING;
5.3.4,
FIXED
DISKCLEANING;
5.3.5,
CARTRIDGE
REMOVAL
AND
HAN
D LI NG: New recommended
head
cleaning products added (ACN 8877).
Paragraph 5.5.9, I
NDEX
ALIGNMENT:
Step I revised.
APPENDIX A
Page
A-1, Item 3: Changed (ACN 81677).
APPENDIX B: Updated Dwgs: S-T 400000 (E-F);
S-F
400001 (D-E); Line
Term D40 Male 301074 (B-C); DEB 301206 (H-J); DCB 301632 (E-G);
EIB 301636 (G-H); Spind.
Lim./5V
301794 (B-C);
I/O
D-40 301936 (B-C).
APPENDIX
C:
Updated Schematics:
DCB
301633 (D-F);
I/O
D40 (A-B).
APPENDIX D
Page
D-15, Item 1 PIN changed.
Page
D-25, Items 2
and
7: PIN changed.
Page
D-26, Figure
D-1
0: Items 36, 37, and 40 deleted
from
Brush Access
Cover hardware.
Page
D-27, Items 1
and
34: P /N changed; Item 36 and 37:
quantity
changed.
Page
D-28: Item 40 deleted.
Page
D-30,
top
item, Assy.,
Fixed OiskCover, Items 11, 17: PIN changed (ACN 81677).
Page
0-8, Figure
0-4:
Art
changed
to
use
WAN-0978-004.
APPENDIX E
Page
E-1: WAR N I
NG
and Figure
E-1
added
following
Table E-1.
LOW IMPEDANCE AOOENOUM
Page
4:
WARNING
and Figure 3 added.
vii
Date
10/77
Page 9
Revision
Level
Super Series Disk Drive
Manual 301462-002
Revision
Level
Description
H
SECTION 2
J
K
L
Paragraph 2.4.6: Note added
re:
head alignment (ACN 11277).
SECTION 5
Paragraph 5.5.4.2: Step H revised (ACN
111277). Paragraphs 5.4.3.4
and
5.4.2.5 revised (ACN 91477).
APPENDIX B
Updated Spindle Switch
PWB
301789 (B1-C).
APPENDIX C
Updated
D I B 301321 (B-C).
Pages
renumbered.
APPENDIX D
Page
D··21:
Item 3 changed; Item 4 added.
Page
0-22:
Item
51
changed.
Page
D-27: Item 5 changed; Item 6 added. Item
19
changed.
Page
0-30:
Item 17 changed.
SECTION 2
Revised: Paragraphs 2.3, 2.4.7.2,2.4.7.3
and
2.4.7.4 (ACN 11778).
SECTION 4
Revised:
Page
4-8, last paragraph,
and
paragraph 4.5.3.4.4.
SECTION 5
Revised: Paragraph 5.5.5.2
and
5.5.5.5. Added new Figure 5-36 (ACN 1478).
APPENDIX B
Updated: Disk Drive ST, 400000 (F-G); Disk Drive
SF,
400001 (E-F);
CIB 301174 (C-D);
PS
301361 (D-E),
SVA
301483(L-M).
APPENDIX C
Updated: CIB
301175 (D-E);
PS
301361 (D-E),
SVA
301484 (J-K).
APPENDIX D (lPB), E (-001 Data),
and
the Low ImpedanceAddendum
deleted from manual.
To
be
supplied on request.
SECTION 5
Paragraph 5.5.5.5:
Change
step B
and
Figure 5-36 (ACN 32478).
SECTION 6
Deleted. To
be
supplied on request.
APPENDIX B
Updated: Disk Drive
ST,
400000(G-H); Disk'Drive SF,400001(F-G); DIB
(VFO), 301320(D-E);
PS,
301631(E-G); SVA, 301483(L-M); EIB, 301636
{H-J);Spindle Switch,
301789 (C-D);Spindle Limiter, 301794 (C-D);
APPENDIX C
Updated: DIB
(VFO); 301321
(C-D);
PS,
301361 (E-G); DCB,301633
(F-G);EIB,301637(C-D)
viii
Date
12/77
2/78
5/78
6/78
Page 10
Revision
Level
M SECTION 1
Super Series Disk Drive
Manual 301462-002
Revision Level
Description
Changed: Table 1-1, 100 TPI track-to-track
access
time
to
10
msec.
Revised: Paragraph 1.3.2.
SECTION 2
Revised: Figure 2-1; Table 2-2
Input
Line column
SECTION 5
Page
5-51, para. 5.5.4.2, Step H: 600
mV
changed
to
800
mV.
Page
5-83: para. 5.5.14, CIB
Adjustment
added (ACN 8478).
APPENDIX
A
Master Spares List, p. A-1, Item
1,
Mag.
Rec.
Hd.
for
4400
BPI
R!W:
301401-001
and
-002 changed
to
301489-005 and -006.
APPENDIX
B
Updated: Disk Drive,
100/200
TPI, ST, 400000 (G-L); DiskDrive,
100/200
TPI, SF, 400001
(F-K);
Control Interface
PWB,
301174
(D-E); Data Electronics
PWB,
301206 (J-K); Servo
Amplifier
PWB,
301483 (M-N); Electronic Interconnect
PWB,
301636 (J-K); Spindle
Drive
Limiter/5V
Drive
PWB,
301794 (D-E);
I/O
Connector D40,
301936 (C-D 1).
APPENDIX
C
Updated: Control Interface
PWB,
301175 (E-F); MFM Data Control-2,
301423 (C-D); Detent
Amplifier,
301458 (B-C); Servo
Amplifier,
301484 (J-L); Servo Logic
PWB,
301688 (A-B);
I/O
PWB
-D40,
301937 (C-D).
ix
Date
9/78
Page 11
Revision
Level
N
P
a
SECTION 1
Super
Series
Disk Drive
Manual 301462-002
Revision
Level
Description
Changed:
Table
1-1
access
times.
SECTION 2
Changed:
Table
2-2
(ACN
11
'178).
SECTION 4
Figure 4-5
revised
(ACN 11178). Figure 4-24 revised.
SECTION 5
Revised:
paras.
5.5.5.1
(Step G); 5.5.5.2; 5.5.5.5 (Step A). Figure
5-31
revised.
APPENDIX B
Updated: Disk Dr.
100/200 TPI, ST, 400000 (L-N); Disk Dr. 100/200
TPI, SF, 400001
(K-M);Spind. Sw. 301789 (D-E).
APPENDIX C
Updated: Det. Amp.
301458 (C-DL
APPENDIX
B
Added:
PWB
I/O
Connector
W/lnterrupt
Option, 301947
(A);
Assy, Piggyback 1/0 Connector
W/lnterrupt
Option, 301952 (C).
APPENDIX C
Added:
I/O
Connector W II nterrupt Option, 301948
(A);
Piggyback--I/O Connector With
Interrupt
Option, 301953 (A).
Revised manual for two-volume split. Volume 1 contains all
text
and associated
art
in
five sections. Volume 2
contains
logic schematics,
PWB
assembly drawings
and material lists, and a Master Spare Parts List.
SECTION 1
Revised completely.
SECTION 3
Added:
Paragraph
3.4
and Figures 3-6
through
3-12 (flow charts)
SECTION 5 (ACN 22279)
Page 5-55, paragraph
5.5.5.1,
step H: Revised
Page 5-60, CAUTION, line
4,
changed: POSITIVE-GROUND
to
POSITIVE-GOING
Page 5-62, paragraph
5.5.5.4:
Updated.
Page 5-62,
Added:
New Figure 5-35; incremented subsequent figures by one.
Page
5-63,
paragraph
5.5.5.5,
steps
Band
C: Updated.
Page 5-64, Figure 5-37 (was 5-36):
Updated
variation callouts.
x
Date
12/78
2/79
6/79
Page 12
RECORD OF REVISIONS
Revision
R
Description
SECTION 5 (ACN 71279)
Revised:
Revised:
Page
5-79, paragraph 5.5.13.1
Page
5-80, Figure 5-43
Date
11/79
xi
Page 13
TABLE
OF
CONTENTS
Section
Paragraph
Page
GENERAL
DESCRIPTION
1.
1
SCOP E ..... ; ..
. . . . . . . . . . . . . .
..
. . . . . . . . . . . . . . . . . . . . . . . . . .
1-1
1.2
INTRODUCTION.
. . . . . . . . . . . .
..
. . .
..
. . . . . .
..
. . . . . . . . .
..
.
1-1
1.2.1 Special
Fea-tures
..................
" . . . . . . . . . . . . . . . . . . . .
..
1-1
1.3
SPECIFICATIONS.
. . . . . .
..
. .
..
. . . .
..
..
. . . . . . . . . . . . . .
..
. . 1-3
1.4
ARRANGEMENT
AND FUNCTION
OF
MAJOR ASSEMBLIES. .
..
1-3
1.4.1 Operator
Controls
and
Status Indicators. . . . . . . . . . . . . . . . . . . . . . . 1-5
1.4.2 Door Assembly
..................................
'.' . . . . . . 1-5
1.4.3 Cartridge Receiver Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
1.4.4
Spindle Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
1.4.5 Head-Positioner Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-6
1.4.6 Electronic Assemblies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-6
1.4.7 RearPaneIAssembly
...............
"
......................
1-7
1.5 FORCED-AIR
CLEANING
SYSTEM. .
..
. . . . . . . . . . . . .
.. . ..
. . .
1-7
2
INSTALLATION
AND
CHECKOUT
2.1
INTRODUCTION.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-1
2.2 UNPACKING
AND
INSPECTION.
. . . . .
..
. . . . . . . . . . . .
..
. . . . .
2-1
2.3
CARRIAGE
SHIPPING RESTRAINT
REMOVAL. . ..
. . . . . .
..
. . .
2-1
2.4
INSTALLATION.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
. . .
..
2-3
2.4.1
Input
Power Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
2.4.2
Interface Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
2.4.3
Electrical Characteristics. . . . . . . . . .
..
. . . . . . . . . . . . . . . . . . . . . . . 2-9
2.4.4
I nput Lines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
2.4.5
Output
Lines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10
2.4.6 R ack-Mou nted Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
2.4.7
Initial
Checkout.
. . .
.. . ..
. . . .
..
. .
..
. . .
..
. . . . .
.. . .•
. . . . . . 2-14
3
OPERATION
3.1
SCOPE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
3-1
3.2 OPERATOR CONTROL
PANEL.
. .
....
. . .
..
. .
.. . ..
. . .
..
. . . .
3-1
3.2.1 Functions
of
Operator
Panel
Controls. . . . . . . . . . . . . . . . . . . . . . . . . 3-2
3.3
CARTRIDGE
LOADING.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
3.3.1
SF
Disk
Drive.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
. . 3-3
3.3.2
ST Disk
Drive.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
3.3.3 Operating the Disk Drive. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
3-8
3.3.4 Timing. . . . . . . . . . . . .
..
. . . . . . . . . .
..
. . . . . . .
..
. . .
..
. . . . .
..
3-10
3.3.5 Temperature Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
3.4 FLOW
CHARTS.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-11
4
THEORY
OF
OPERATION
4.2
INTRODUCTION..
. . . . . . . .
..
. . . . . . .
..
. . . . . . . . . .
..
. . . . . . .
4-1
4.3
SC.OPE
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
4-1
4.3
MECHANICAL
DESCRIPTION.
. . . . . . . . . . . . . . . . . . . . . . . . . .
..
4-1
4.3.1 Spindle/Drive
Motor
Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-1
4.3.2 Positioning Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
4.4
SYSTEM ELECTRONIC THEORY. .
.. . .. .. . .. ..
..
. . . . . .
..
. .
4-11
4.4.1 Functional Block Diagram Description. . . . . . . . . . . . . . . . . . . . .
..
4-11
4.5 LOGIC BOARD CIRCUIT
ANALYSIS.
. . .
..
. .
...
..
. . .
.. . ..
. . 4-17
4.5.1
I/O
Connector Board (lOB).
.. . ..
. . .
.. .. . ...
..
. . .
.. . ..
. . .
..
4-17
4.5.2 Electronics
Interconnect Board (EIB)
...
: . . . . . . . . . . . . . . . . . . . . 4-20
xii
Page 14
Section
4
TABLE
OF CONTENTS (continued)
Paragraph
Page
4.5.3
4.5.4
4.5.5
4.5.6
4.5.7
4.5.8
4.5.9
4.5.10
4.5.11
4.5.12
4.5.13
4.6
4.6.1
4.6.2
4.6.3
4.6.4
4.6.5
Disk
Control Board (DCB). . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
4-20
Servo
Logic Board (SLB). . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
4-27
Servo
Amplifier
Board (SVA). . . . . . . . . . . . . . . . . .
..
.......
4-32
Data Electronics Board (DEB). . . . . . . . . . . . . . . . . . . . . . . . .
..
4-37
Control Interface Board (CIS). . . . . . . . . . . . . . . . . . . . . . . . .
..
4-43
Data Interface Board
VFO II (DIB)
........................
4-45
Modified Frequency Modulation (MFM) Board. . . . . . . . . . .
•
..
4-50
Spindle Drive
Limiter
Board. . . . . . . . . . . . . . . . . . . . . . . . . . .
..
4-53
Motor
Drive Power Switch Board. . . . . . . . . . . . . . . . . . . . . . .
..
4-53
Commutator Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
4-54
Emergency Retract Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
4-55
SCHEMATIC
DIAGRAM
ANALySiS
.....................
4-55
Scope
of
Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
4-55
I nitial
Seek
Operation
..
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
4-56
Program
med
Seek
...........................
. . . . . . .
..
4-61
Restore
Operation.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
4-61
ReadlWrite Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
4-64
5
MAINTENANCE
5.1
INTRODUCTION. . .
..
. . . . . . . . . . . . . . . . . . . . . . . . . . .
.. ..
5-1
5.2
SCOPE
OF
MAINTENANCE.
. . . . . . . . . . . . . . .
..
. . . . . . . . . .
5-1
5.3 PREVENTIVE
MAINTENANCE.
. . . . . . . . . . . . . . . . . . . . . .
..
5-3
5.3.1
Preventive Maintenance Schedule. . . . . . . . . . . . . . . . . . . . . . .
..
5-3
5.3.2 ReadlWrite
Head
I nspection
and
Cleaning. . . . . . . . . . . . . . . .
..
5·4
5.3.3 Fixed Disk Cleaning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
5-5
5.3.4 Cartridge Removal
and
Handling. . . . . . .
..
. . . . . . . . . . . . . . .
..
5-5
5.3.5 DiskDrive Top
Cover Removal. . . . . . . . . . . . .
..
. . . . . . . . . .
..
5-7
5.4
CORRECTIVE
MAINTENANCE.
. . . . . . . . . . . . . . . . . . . . . .
..
5-7
5.4.1 General Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
5-7
5.4.2 Removal
and
Replacement
of
Major Assemblies. . . . . . . . . . . .
..
5-16
5.4.3 Removal
and
Replacement
of
Subassemblies. . . . . . . . . . . . . .
..
5-27
5.5 ADJUSTMENT
AND
CALIBRATION
PROCEDURES. . . . . .
..
5-45
5.5.1 Table
of
Adjustments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
5-45
5.5.2
Power Supply Adjustment. . . . . . . . . . . . . .
..
..............
5-46
5.5.3 Spindle
Phasing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
...
5-47
5.5.4
I ndex/Sector Transducer Adjustment. . . . . . . . . . . . . . . . . . . .
..
5-47
5.5.5
SVA
Adjustment Procedures. . . .
..
. . . . . . . . . . . . . . . . . . . . .
..
5-54
5.5.6
SV A Operational Checks. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
5-65
5.5.7 Temperature Compensation
Check. . .
..
. . . . . . . . . . . . . . . . .
..
5-66
5.5.8 Ready
Inhibit
Check. . .
..
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
5-68
5.5.9
I ndex Alignment.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
5-69
5.5.10 Write Current Check. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
5-71
5.5.11 Read/Write
Head
AI ignment. . . . . . . . . . . . . .
.. . .......
;
....
5-73
5.5.12 Data Separator Operational
Check. . . . . . . . . . . . . . . . . . . . . .
..
5-78
5.5.13 M F M Adjustments
(4400
BPI
Disk Drives Only). . . . . . . . . . . .
..
5-79
5.6
TROUBLESHOOTING.
. . . . . . . . . . . . . . . .
..
. . . . . . . . . . .
..
5-83
xiii
Page 15
Figure
2-1
2-2
2-3
2-4
2-5
2-6
3-1
3-2
3-3
3-4
3-5
3-6
3-7
3-8
3-9
3-10 .
3-11
3-12
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
4~11
4-12
4-13
4-14
4-15
4-16
4-17
4-18
4-19
4-20
4-21
4-22
4-23
4-24
4-25
4-26
4-27
4-28
4-29
.4-30
4-31
4-32
4-33
4-34
LIST
OF
ILLUSTRATIONS
Title
Page
Frontispiece, Super Series Magnetic Disk Drives
.........................
xviii
Shipping Container and Parts
.....................................
2-2
Carriage
Shipping Restraint
.......................................
2-4
Multiple
Disk Drive I nstallation (Daisy Chaining)
......................
2-6
Rear Panel and
I/O
Connector Board
...............................
2-8
Rack-Mounted
I nstallation Instructions
.............................
2-13
By-Passing
Top
Cover I
nterlock
Switch
..............................
2-15
Operator
Controls
..............................................
3-1
Series F Disk Drive Cartridge Loading
...............................
3-4
Series T Disk Drive Cartridge Loading
...............................
3-5
Operating the
SF
or
ST Disk Drive
.................................
3-6
Power
ON/Off
Sequence
.........................................
3-10
Power-up and Cartridge Loading (Load Mode)
.......................
3-11 I
Run Mode - I
nitial
Cycle
.......................................
3-12
Run Mode -
Cylinder
000
Seek
..................................
3-13
Run Mode - New Address
Seek
..................................
3-14
Run Mode -
Write
Operation
....................................
3-15
R un Mode -
Read
Operation
....................................
3-16
Turn-off
Cycle
................................................
3-17
Simplified
Block Diagram
........................................
4-2
Spindle/Drive
Motor
Assembly
...................................
.4-3
Three Types
of
Sector Rings
.....................................
.4-5
Positioner Assembly
...........................................
.4-6
Optical Transducer Diagram
.....................................
.4-7
Movable
Optical Glass
...........................................
4-7
ReadIWrite Heads
..............................................
4-9
Head Unloading Mechanism
.....................................
.4-10
Block
Diagram - Super Series (major signal lines)
.....................
.4-13
Block
Diagram - Super Series (major signal lines)
4400
BPI
only
.........
4-14
Functional
Block
Diagram - Head Positioning System
.................
4-15
Functional
Block
Diagram - Read/Write
Circuit
......................
4-16
Block
Diagram -
I/O
Board
.....................................
4-18
Spindle
Motor
Speed Detection and
Control
Functional
Block
Diagram. .
..
4-21
Spindle
Motor
Control
Simplified
Logic
Diagram.
. . . . . . . . . . . . . . . . . .
..
4-21
Motor
Speed
Control
Timing
Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
4-22
Removable Disk
I ndex/Sector
Separation.
. . . . . . . . . . . . . . . . . . . . . . . .
..
4-24
Removable
I
DX/STR
Pulse
Timing
Diagram. . . . . . . . . . . . . . . . . . . . . . .
..
4-24
Disk
Control
Signals -
Simplified
Logic
Diagram.
. . . . . . . . . . . . . . . . . .
..
4-25
Block Diagram
of
Servo Logic Board (SLB)
.........................
4-28
Subtractor
Circuit -200
TPI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
4-30
Illegal
Address Gating Circuits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
4-31
Block
Diagram
of
Servo
Amplifier
Board
(SVA)
. . . . . . . . . . . . . . . . . . . .
..
4-33
New
Address Seek Operation Waveforms . . . . . . . . . . . . . . . . . . . . . . . . .
..
4-36
Positioner
Servo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
4-37
alock
Diagram
of
Data Electronics Board (DEB)
.............
,.......
4-38
Disk/Head
Selection Decoder
.............
, . . . . . . . . . . . . . . . . . . . .
..
4-39
Block Diagram
of
ReadIWrite
Amplifier
..........
,
...
, ,
...... , .. , ,.
4-40
ReadlWrite Signals
- Relative
Timing
...........................
,
..
4-41
Edge Erasing
...... , ... , ..... , .... , ... , ......
, ,
...........
, .
..
4-42
Block
Diagram
of
CI B ........
, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
4-44
Current
Sector
Identification
(CIB)
................................
4-46
Output
of
Double-Edge Discriminator. . . . . . . . . . . . . . . . . . . . . . . . . . . .
..
4-47
Data
I nterface and
VFO
Timing
Diagram.
. . . . . . . . . . . . . . . . . . . . . . . .
..
4-48
xiv
Page 16
Figure
4-35
4-36
4-37
4-38
4-39
4-40
4-41
LIST OF I
LLUSTRATIONS
Title
Double-Frequency-Modulated
Simplified Logic Diagram -
\/Vaveshape
Read
Simplified Logic Diagram - Write
Simplified Diagram
Head
Load Timing Diagram
Programmed
Seek
Timing Diagram
of
Brushless
......................................
(1
and 2 Cyl inder
of
Restore Operation
Motor
(continued)
. . . . . . . . . . . . . . . . . . . . . . . . .
Circuitry
r.ircuitry
Seeks)
.........................
. . . . . . . . . . . . . . . . . . . . . . .
Circuit
.......................
.........................
..............................
..
..
Page
4-49
4-51
4-52
4-54
4-59
4-62
4-63
5-1
5-2
5-3
5-4
5-5
5-6
5-7
5-8
5-9
5-10
5-11
5-12
5-13
5-14
5-15
5-16
5-17
5-18
5-19
5-20
5-21
5-22
5-23
5-24
5-25
5-26
5-27
5-28
5-29
5-30
5-31
5-32
. 5-33
5-34
5-35
5-36
5-37
5-38
5-39
5-40
5-41
5-42
5-43
5-44
5-45
5-46
Fixed Disk Cleaning Hole Location
Cartri.dge I nterlock Switch
SF
Wit"
Cover Removed
ST
with
SF
Cover Removed
and ST Disk Drives Assembly
Actuation
.........................................
.........................................
Series F DiskDrive - Simplified
Series T Disk Drive - Simplified
Removal/Replacement Guide - Major Assemblies
Top
Cover Hole Alignment
Power Supply Assembly
Positioner Assembly
Spindle Assembly
..............................................
Disk Brush Drive Mechanism
.......................................
.........................................
............................................
......................................
Removal/Replacement Guide - Subassembl
Air
Filter
Installation
...........................................
Blower Shaft Ground Brush - Mounting
Spindle Shaft Ground Brush - Mounting
.................................
- ST
...........................
Identification -Bottom
Front
Front
View
..........................
View
..........................
.....................
ies
........................
.............................
............................
Disk Cleaning Brushes - I nstallation/Replacement Guide
Cartridge I nterlock Switch Assembly
Removable I ndex/Sector Transducer - Series F
Fixed and Removable Index/Sector Transducer
Read/Write
Torque Wrench No. T-00425
Emergency Retract
Power Supply Connections -
Shutter Adjustment -
Head
Assembly
PWB
Assembly
Commutator
.......................................
Application
Commutator
Cartridge Sector/I ndex Transducer
Fixed Disk Sector/Index Transducer
Input
to
Detent Signal
Differentiator
Phasing
Adjustment
Output
Board (SF)
Waveform (manual)
VVaveform
....................................
Optical Detent Assembly - Phasing
...............................
Only
...................
.......................
............................
.................................
Board Phasing Adjustment
Board
VVaveshape
...........................
........................
Waveshape
.......................
.... " ............................
............................
Adjustment
.......................
100 TPI Drive - Detent Waveform - Alternate One Track
200 TPI Drive - Detent
Fine Balance
Fine Offset
Detent Signal
Adjustment
Adjustment
Output
I ndex-to-Data Alignment (2400 rpm shown)
Write Current Waveform - Track
Write Current Waveform - Innermost Track
Read/Write
Data Separator
M FM
Timing
Checking
Write Clock
Head
Alignment
Output
Timing
Relationships Diagram
Relationship Between MFM
with
an
to
Data
Two-speed Emergency Retract
VVaveform
- I ncrementing One Track
....................•.....•.....•.......
................•.........•.............•.
Waveforms
................••...............•
000
.........................•.....
Waveforms (Removable Disk)
Waveform
................•..........•.•....
.........•................•...••
DATA
Exerciser
Timing
...........................•.....•....•
Adjustment
...........•.................
...................................
............•....•......•.
........................•.
and
CLOCK
View
..........
Seek
...........
Seek
...............
for
Error
..........
,
......
........
.....
5-6
5-6
5-8
5-9
5-10
5-11
5-12
5-17
5-18
5-19
5-21
5-25
5-27
5-28
5-30
5-33
5-34
5-34
5-35
5-37
5-38
5-40
5-42
5-44
5-48
5-49
5-50
5-52
5-53
5-56
5-56
5-58
5-61
5-61
5-62
5-63
5-64
5-70
5-72
5-72
5-74
5-79
5-80
5-81
5-82
·5-83
Page 17
LIST
OF
TABLES
Table
1-1
2-1
2-2
2-3
2-4
4-1
5-1
5-2
5-3
5-4
5-5
5-6
Title
Specifications - Super Series Disk Drives
Packaging Container Parts
I nterface Pin Assignments
Printed Wiring Board
Glossary
Normal Run
of
Mnemonic
Switching
Preventive Maintenance Schedule
.......................
....................................
Acronyms
Terms
Sequence
...............................
.................................
..............................
..............................
........................
Standard and Special Accessories and Service
Table
of
Adjustments
Temperature Compensation Voltage
CE
Cartridge Head
Fault
Isolation Chart
.......................................
...........................
Alignment
Tracks
...........................
........................................
Aids
.................
_
............
Page
1-4
2-3
2-5
2-6
2-7
4-55
5-2
5-14
5-46
,5-68
5-75
5-84
xvi
Page 18
Page 19
Front
Load - Series
SF
Top
Load - Series
ST
Frontispiece -Super
Series Magnetic Disk Drives
Page 20
SECTION 1
GENERAL
DESCRIPTION
1.1
SCOPE
This manual describes operation and maintenance
of
Super Series Disk Drives manufactured
by
Perkin-Elmer Memory Products Division, and
is
divided
into
two
volumes.
Volume
1 contains the
following
five sections:
Section 1
Section 2
Section 3
Section 4
Section 5
General Description
I nstallation and Checkout
Operation
Theory
of
Operation
Maintenance
Volume 2 contains the
following
three sections:
Section 1
Section 2
Section 3
Logic Schematics
Assembly Drawings
Master Spare Parts List
1.2
INTRODUCTION
Super Series Disk Drives
are
front-loading (SF)
or
top-loading (ST), 100
or
200
tracks-per-inch
(TPI) (tracks per 2.54 cm), random-access, high-capacity data storage devices whose compact size,
-optimum
performance, and
reliability
make them exceptionally suitable
for
use
in
computer
sys-
tems
of
small and medium size. Several models are available in
each
series
with
a choice in storage
capacities and transfer rates.
In standard versions the units incorporate, in either series,
an
integral permanent disk and a remov-
able disk
of
the cartridge-type
offering
a gross storage capacity
of
up
to
200
megabits. Recording
density
is
2200
or
4400
bits per inch (BPI) (bits per 2.54 cm).
NOTE
Throughout
th
is
manual all references
to
tracks
per inch
(TPI)
or
bits per inch (BPI)
are
intend-
ed
to
relate
to
tracks per 2.54 centimeters (cm)
or
bits per 2.54 centimeters (cm).
1-1
Page 21
The
SF
Disk Drive
uses
a front-loading cartridge
of
the IBM 2315-type; the ST Disk Drive
uses
a
top-loading cartridge
of
the IBM 5440-type.
All
4400
BPI
models
use
modified cartridges
with
IBM
3300-type media.
The
SF
and ST Disk Drives incorporate
an
interface compatible
with,
or
adaptable to, controllers
for
most major disk file systems. I ntegral daisy-chain provisions
permit
the interconnection
of
up
to
four
Disk Drives.
The disk drives in either
series
feature modern functional exterior styling
and
are
rack-mounted in
cabinets
of
standard
RETMA
dimensions. The
SF
unit
requires
only
7 inches (17.78 cm)
of
vertical
rack space; the
ST
unit
requires
only
7-%
inches (19.68 cm).
1.2.1 SPECIAL
FEATURES
The
SF
and
ST
Disk Drives incorporate advanced electronic
and
mechanical design features
that
contribute
to
their exceptional performance and reliable operation. Routine service requirements
are minimal,
and
corrective maintenance, should
it
become necessary,
is
facilitated through the
efficient
layout
and
accessibility
of
all components. Some
of
the notable design features are:
A. The disk spindle
and
the drive
motor
are
combined in
an
integral assembly; thus
eliminating a drive
belt
and
pulleys.
B.
The spindle
motor
is a DC
brushless
unit,
and its
speed
is
held constant
within
± 1 percent regardless
of
line voltage
and
frequency fluctuations. Therefore, the
storage
of
data in any given sector
of
the disks
can
be
maximized.
C.
Either
of
two
spindle
speeds
are
available: 1500
or
2400 rpm (4400
BPI
available
at 2400 rpm only).
D.
The head-positioning system
uses
a highly
efficient
electromagnetic actuator
which although
it
permits fast
access
times,
has
low
power dissipation
and
very
low
flux
leakage. Final
head
positioning
is
implemented through
an
optical-
electronic -
not
mechanical - detenting system.
E.
Write Protect
circuitry,
selectable at the operator control panel (OCP),
is
provided
for
protection
of
previously recorded data on either the fixed
or
cartridge disk.
Write
Inhibit
circuitry
is
provided
to
inhibit
writing
before the Ready signal
is
sent
to
the Controller. An
option
for
200 TPI disk drives
only
is
available
to
in-
hibit
writing
until
a temperature balance
is
achieved in the Temperature Compen
sation
Circuitry.
F.
A highly
efficient
clean-air system, continuously purges the
interior
of
the disk
drive and pressurizes it. Intake air
is
passed
through a dual
filter
element, purges
the disks and heads,
and
cools the electronic assemblies before exiting the disk
drive.
1-2
Page 22
G. Internal flexible
I/O
signal
and
AC
power cables interconnect the receptacles
mounted on the rear panel
of
the disk drive
with
the corresponding electronic
assemblies in the disk drive. This feature permits permanent
mounting
of
the rear
panel in the cabinet and makes
it
possible
to
slide the disk drive
out
without
dis-
connecting
or
manipulating the external cables.
H.
A
built-in
universal
power
supply allows operation on any
of
the
world's
standard
AC power voltages and frequencies.
1.3 SPECIFICATIONS
Specifications
for
the
SF
and
ST Disk Drives
are
listed in Table 1-1.
1.4
ARRANGEMENT
AND
FUNCTION
OF MAJOR ASSEMBLIES
The
SF
and
ST
Disk Drives are identically constructed except
for
mechanical differences in the car-
tridge loading and seating mechanisms and
door
and cabinet locks. Assemblies and characteristics
common
to
both
series
are
shown and described in the
following
paragraphs. Three-quarter
front
views showing component locations
are
included in Section 5.
1.4.1 OPERATOR CONTROLS
AND
STATUS
INDICATORS
Controls and associated status indicators
are
located on a panel below the plastic door. These in-
clude the switches
with
which the operator starts
and
stops the Disk Drive, selects the
unit
address
(in multiple-disk drive installations) and
write
protect indicator/switches
for
both
the removable
and fixed disks. The
function
and operation
of
each
switch and indicator
is
described in Section
3.
1.4.2 DOO R ASSE
MB
L Y
I n the
SF
Disk drive, the
door
rotates forward approximately 60 degrees,
and
the cartridge
is
in-
serted through the resultant opening. When the
door
is
opened, the cartridge receiver
is
simultane-
ously elevated and advanced.
In the
ST
Disk Drive, the
door
rotates forward approximately
30
degrees.
As the
door
is
pulled
open, a locking mechanism disengages the stationary
mounting
slides. The disk drive
can
then
be
slid
out
of
the rack,
and
the cartridge
can
be
loaded on the spindle
as
described in Section
5.
1.4.3
CARTRIDGE
RECEIVER ASSEMBLY
This assembly
is
used
only
in the
SF
Disk Drive. The receiver
is
mechanically coupled
to
the door-
loading assembly.
It
holds the cartridge
and
automatically positions
it
over the spindle. The car-
tridge
is
locked on the spindle chuck
as
the
door
is
closed.
1-3
Page 23
Table 1-1. Specifications - Super
Series
Disc Drives
Parameter
100 TPI
200 TPI
Gross
Capacity
25
or
50
Me~abits
50, 100
or
200 Megabits
Transfer Rate
1562,
2500 Kbits/sec 1562, 2500
or
5000 Kbits/sec
Track Density
100 TPI
200 TPI
Recording Density
2200
BPI
2200
or
4400
BPI
Maximum
Speed
Variation
±1%
±1%
Access
Times
Track-to-track
11
msec
10
msec
Average
37.5
msec
37.5
msec
Maximum
67
msec
67
msec
Recording Mode
Double freq. encoded
Double freq. encoded
or
modified freq. modulation
Disk
Speed
1500
or
2400 rpm
1500
or
2400 rpm
Cartridge Unload/Load
Cycle
Load Cycle
60
seconds
60
seconds
Cartridge -
Series
SF
IBM 2315-type
IBM 2315-type
Cartridge -
Series
ST
IBM 5440-type
IBM 5440-type, modified IBM
Built-in Power Supply
3300-type
media
for
4400 BPI
Requirements
100,110,120,130,200,
100,110,120,130,200,220,
220,230,240,250,260
230,240,250,260
V AC
VAC±
10%,
47-63Hz,
±
10%,
47-63Hz, 250
VA
250
VA
Physical Dimensions
Height -
Series
SF
7.00 in. (17.78cm)
7.00 in. (17.78cm)
Height -
Series
ST
7.75 in. (19.68 cm)
7.75 in. (19.68 cm)
Width -Series
SF
and
Series
STI
17.60 in. (44.70 cm)
17.60 in. (44.70 cm)
Weight
100 lb. (45.36
kg)
100 lb. (45.36
kg)
Environment, Operational
Temperature
50
to
100°F
(10
to
38'oC)
50
to
100°F
(10t03SoC)
Relative
Humidity
10-80%,
noncondensing
10-80%,
noncondensi
ng
Environment, Shipping and
Storage
Temperatu
re
-40
to
+1500F
(-40
-40
to
+1500F
(-40
to
+650C)
-i~
+65
0
C)
Relative
Humidity
5-95%
5
-95%
1-4
Page 24
1.4.4 SPINDLE
ASSEMBLY
The spindle assembly provides the mechanical coupling between the recording disks
motor.
only
The fixed disk
is
when the cartridge
mounted
is
fully
directly
on the spindle
hUb.
The cartridge disk
seated in the disk drive. Coupling
is
accomplished
spindle-mounted/magnetic chuck; i.e., a ring magnet and a circular pole piece, and
fastened
A conical
of
ring also
bly
is
dynamically braked when a Stop cycle
1.4.5 HEAD-POSITIONE R ASSEMB
The head-positioner mechanism positions the read/write
the fixed
The head-positioner assembly contains
tor,
ponents
to
the cartridge disk.
point
on the center
of
the spindle
engages
an
identically machined opening in the center
the cartridge disk; thereby accurately aligning the disk on the spindle hub. The fixed disk sector
is
without
mounted on the spindle hub. The spindle
using a
belt;
therefore,
it
becomes
is
initiated
motor
an
integral part
(see
is
coupled
of
Section 4).
directly
to
the spindle assembly. The spindle
LY
heads
over the selected
or
removable disk.
the
carriage, carriage guides,
of
the head positioner
following
head
loading/unloading cams,
form
an
integral assembly
components:
and
that
can
an
electromagnetic linear actua-
a positioner transducer.
be
independently removed
and
engages
an
the spindle
by
means
armature plate
the spindle
cylinder
the drive
(track) on
All
the disk drive.
of
assem-
com-
from
a
1.4.6
The disk drive contains
on which the connectors
ELECTRONIC
seven
ASSEMBLIES
plug-in printed
for
positioner assembly contains the
A. Data Interface Board
B.
Control Interface Board (CIB) at connector J2
C.
Disk Control Board (DCB) at connector
D.
Servo Logic Board (SLB) at connector J4
E.
The Detent
Amplifier
supply and the
Servo
head
Amplifier
Board
(DAB)
positioner.
wiring
boards (PWB's) and a central' interconnect
the plug-in PWB's are mounted. The frame adjacent
following
PWB's
(DIB)
(see
Section 5
at
connectorJ1
for
physical locations):
J3
Board (SVA) at connector J5
is
a small daughter-board
that
plugs
into
J 14 between the power
1-5
to
the head-
PWB
Page 25
Connector numbering
J1
is located nearest
is
located on the opposite side
to
is
the
from
edge
left
to
right
as
viewed
of
the casting. The Data Electronics Board (DEB) at connector J7
of
the disk drive in
from
front
the
front
of
of
the power supply.
the disk drive; i.e., connector
The power supply assembly furnishes the operating voltages
regulated)
fuses
1.4.7 REAR
The
for
all electronic assemblies, the head-positioner, and the spindle and brush motors.
are
provided on this assembly. The power supply can
PANEL
I/O
Connector Board (lOB)
ASSEMBLY
is
mounted on the rear panel and contains the signal
be
(±
18 VDC unregulated; +5 VDC
removed
as
one integral
connectors, line drivers, and receivers.
In cabinet installations, the rear panel is stationary;
but
remains in the cabinet. The electrical connections between the panel and the disk drive
tablished
1.5 FORCED-AI R
The
highly filtered air.
operation, the
by
means
SF
and ST Disk Drives contain a forced-air system
of
Air
interior
flexible cables.
CLEANING
is
drawn
of
the
disk drive
from
SYSTEM
outside the cabinet and cools the electronic assemblies. During
is
at slightly elevated pressure,
that
is,
it
does
that
purges the disk
not
slide
with
out
with
and
respect
unit.
input/output
the disk drive
head
areas
to
the ambient,
are
with
DC
es-
which
The components
filter
is
metal plates
serves
element
to
keep dust
of
is
contained in the rectangular cavity
from
the forced-air system
located on the opposite side
(see
Section 5
for
the physical location
entering the disk drive.
of
the spindle. Both components
Intake air enters the disk drive at the
ambient air
passes
exits via the
is
circulated through the disk drive. The incoming air
through the plenum chamber then through the
head
entry
door
of
the cartridge and through the lower head
are
front
accessible
next
of
panel
from
1-6
from
below the
to
the spindle assembly. The blower fan
are
base
covered
casting. The dual air-
by
these components).
above.
filter
With
this
arrangement,
is
accelerated
element and over the disk surfaces.
area.
individual sheet-
only
fresh
by
the blower,
It
Page 26
SECTION 2
INSTALLATION
AND
CHECKOUT
2.1
INTRODUCTION
This section contains unpacking and installation instructions and a description
of
the interface
for
the Perkin-Elmer Super Series
SF
(front-loading) and ST (top-loading) Disk Drives.
2.2
UNPACKING
AND
INSPECTION
SF
and ST Disk Drives
are
shipped in special containers designed
to
provide
full
protection
under
normal
transit
conditions. I mmediately upon receipt, the shipping container should
be
inspected
for
evidence
of
possible damage incurred in transit.
Any
obvious damage
to
the
container,
or
indications
of
actual or probable equipment damage, should
be
reported
to
the carrier company
in accordance
with
instructions on
the
form
included in
the
container.
Figure
2-1
shows
an
exploded view
of
the palletized packaging container and its parts. Table
2-1
lists
the
parts
with
full
descriptions in accord
with
item numbers
used
in the. figure.
To
unpack the disk drive, open the
top
side
of
the shipping container and remove the
two
Etha-
foam
flotation
frames, packaging spacers, and rectangular cardboard
sleeve.
Then
carefully
remove
the
plastic
bag
and
use
care
to
avoid tearing the bag.
All
of
these components should
be
saved
in
case
it
may
be
necessary
to
relocate the
unit
at a later date. A shipping package (PIN
T-00287
may
be ordered
from
the Company.
When the plastic
bag
has
been removed, grip
the
unit
along
both
sides
of
the casting
while
lifting
it
out
of
the container.
Do
NOT
support
the
unit
by. the handle on the
front
panel. The finished
surfaces and the plastic part
of
the
front
panel should also
be
handled
with
reasonable care
to
avoid marring.
2.3
CARRIAGE
SHIPPING
RESTRAINT
REMOVAL
For
protection
during
shipping,
the
carriage
of
the positioner assembly
is
held back against
the
rear stop
by
a shipping restraint shown in Figure 2-2.
This
restraint immobilizes the carriage, heads,
and associated parts.
Plug P16 on the Power Supply
is
shipped disconnected
to
preclude possibility
of
power
being inadvertently applied
to
the
disk drive while the shipping restraint
is
still installed.
The shipping restraint must
be
removed before the disk drive
can
be
operated.
To
remove
the
shipping restraint, remove
the
restraint retaining screw located at the rear
of
the positioner. This
screw
is
shown in the
INSTALLED
POSITION
(see
Figure 2-2). Reinstall the shipping restraint
as
shown in the STOWED POSITION
(see
Figure 2-2).
NOTE
The restraint retaining screw holds the carriage
rear stop and must be reinstalled.
2-1
Page 27
SUPER SERIES
1088-002
12
PACKING LIST ENVELOPE
Figure 2-1. Shipping Container
and
Parts
2-2
Page 28
Item No.
1
2
3
4
5
6
7
8
9
10
11
12
13
Table 2-1. Packaging Container Parts
(see
Figure 2-1)
Part No.
Description
T
-00287 -001
Outer
Stitched Box
T-00287-002
Flotation Frame
T
-00287 -003 Inner Box
T
-00287 -004
Mounting
Base
Bolt, Hex
%-20
UNC x 1-1/2
Washer
%
10
x
3/400
'Bolt, Hex
3/8-16 UNC x 1-1/2
Washer
3/8
10
x
3/4
00
5003
Polystyrene
Bag
T-00287-005
Sleeve
T-00128
Shipping
Damage
Notice Form
T
-00180-007
Dust Cover, Shroud
(series
"T"
only)
200951-001
Technical Manual Vol. 1
and
2
NOTE
The Shipping restraint must
be
removed before
the Disk Drive
can
be
operated.
2.4
INSTALLATION
2.4.1 INPUT
POWER
REQUIREMENTS
The standard Perkin-Elmer Super
Series
Disk Drive contains
an
integral power supply which
can
accept
anyone
of
the AC
input
voltages
(see
Table 1-1). The power supply frequency may
range
from 47Hz
to
63Hz. The appropriate
input
connections
are
established via a voltage selection plug
located next
to
the power transformer.
PRIOR TO CONNECTING THE AC LINE CORD
TO
THE
POWER
SOURCE,
VERIFY
THAT
THE
VOLTAGE
PLUG
IS
COMPATIBLE WITH THE
LINE
VOLTAGE
AT
THE
INSTALLATION
SITE.
EXAMINE
THE
POWER
SPECIFICATION DECAL
ON
THE REAR PANEL OF THE UNIT.
If
the transformer tap connections
are
changed
to
accommodate a
different
primary power source,
the
voltage marking decal should
be
changed
to
show the correct voltage rating
for
the disk drive.
Precut decal markers
of
nonconductive B-500 vinyl cloth
are
available from Perkin-Elmer
for
this
purpose. These decals
can
be
ordered in the following configurations:
Perkin-Elmer"P/N Legend
Perkin-Elmer
PIN
Legend
Perkin-Elmer
PIN
Legend
133501-100
100
VOLTS
133501-120 "
120
VOLTS
133501-230
230
VOLTS
133501-110
110
VOLTS
133501-210
210
VOLTS
133501-240
240
VOLTS
133501-115
115
VOLTS
133501-220
220
VOLTS
133501-250
250
VOLTS
2-3
Page 29
·1089-002
POSITIONED
RETRACT SWITCH
ACTUATOR
ON
a.
INSTALLED
POSITION
RESTRAINT
RETAINING
SCREW
"SHIPPING
RESTRAINT
b.
STOWED POSITION
Figure 2-2. Carriage Shipping Bestraint
2-4
Page 30
2.4.2
INTERFACE
REQUI REMENTS
The physical configuration and electrical requirements
for
SF
and ST Disk Drives
are
described in
the
following
subparagraphs.
See
Table 2-2
for
interface signal pin assignments.
See
Table 2-3 and
2-4
for
explanation
of
acronyms and
~nemonics
used
throughout
this manual.
Table 2-2. I nterface Pin Assignments
Input
Line Pin
Output
Line
Pin
Cyl
Add
2
0
44
Ready
11
CylAdd2
1
39
Seek
Complete
16
Cyl
Add
22
43
Address Acknowledge
14
Cyl Add 2
3
42
Seek
Incomplete
15
Cyl Add 24
45
Illegal Address
13
Cyl
Add
25 '
47
Attention
Unit
0
20
Cyl
Add
2
6
48
Attention
Unit
1
17
Cyl
Add
27
50
Attention
Unit
2
19
Cyl
Add
2
8
29
Attention
Unit
3
18
Cyl
Add
Strobe
32
Read
Data
7
Restore
38
Data Clock
8
Disk Select
31
Index
9
Head
Select
33
Sector
6
Write Gate
36
Sector Address 2
0
4
Erase
Gate
40
Sector Address
21
2
Write Data
41
Sector Address 22 26
Read
Gate
49
Sector Address 2
3
1
Unit
Select 0
34
Sector Address 24 3
Unit
Select 1
35
Pseudo Sector
5
Unit
Select 2
27
Write Check
10
Unit
Select 3
28
Termination Voltage
25
Termination Voltage
25
Write Protected
12
Track Offset Fwd.
46
Ground
21
Track Offset
Rev.
37
Ground
22
Ground
23
Ground
24
200 TPI Status
30
2-5
Page 31
Table 2-3. Printed Wiring Board Acronyms
Acronym
Meaning
Location
CIB
Control I nterface Printed Wiring Board
J2
DCB
Disk Control Printed Wiring Board
J3
DEB
Data Electronics Printed Wiring Board
J7
DIB
Data Interface Printed Wiring Board
J1
EIB
Electronics I nterconnect Printed Wiring Board
*
lOB
Input/Output
Connector Printed Wiring Board
**
MFM
Modified Frequency Modulation Printed \I\Iiring Board
***
SLB
Servo Logic Printed Wiring Board
J4
SVA
Servo
Amplifier
Printed Wiring Board
J5
*
Mother board upon which jacks J 1 through J7
are
located.
**
Board mounted
directly
to
rear panel.
***
Board
only
used
in
4400
BPI
machine. Replaces
DI
B in J
1.
2.4.2.1 Cabling. Interface between disk drive and Controller
is
accomplished
with
one cable.
The connector at the disk drive
is
Amphenol No. 57-10500-27 (Perkin-Elmer
PN
101036-001).
The corresponding mating connector
for
the cable
is
Amphenol No. 57-20500-31 (Perkin-Elmer
PN
101037-001) and
is
supplied
with
the drive.
I/O
signal cables
are
28 AWG twisted pairs.
Total
(system) cable length should
not
exceed 50 feet
(15.24 meters)
or
30 feet (9.144 meters)
for
4400 BPI.
An
AC power cable, Perkin-Elmer
PN
101153, and all described cables
are
supplied
with
the drive.
2.4.2.2
I nterconnection (Daisy Chaining)
of
Disk Drives. Daisy chaining
of
up
to
four
drives
is
permitted
by
an
integral system
of
two
connectors mounted on the I/O board. The last drive in
the chain must
be
terminated
with
a detachable Line
Terminator
Assembly (Perkin-Elmer
PN
300095-001). A daisy chain interconnecting cable Perkin-Elmer
PN
300118-XXX;
XXX
= length
in inches)
is
used
to
interconnect the drives.
See
Figures 2-3
and
2-4.
CENTRAL
CONTROLLER
DISK
DRIVE
/
UNITO
UNIT
1
UNIT
2
Figure 2-3.
Multiple
DiskDrive
Installation (Daisy Chaining)
2-6
1111·001
Page 32
Table 2-4. Glossary
of
Mnemonic Terms
Mnemonic
Meaning
Origin
ADD1-128/256
Track (Cylinder) Address
Controller
ADD
ACK
Address Acknowledge
CIB
AC
LOSS
Alternating Current
Loss
DCB
ATTEN
Attention
CIB
BOT
Beginning
of
Travel pulse
Detent
Amplifier
board
CAR
Cylinder Address Register
SLB
D DAC
Output
of
Digital-to-Analog Converter
SLB
DC
LOSS
Direct Current
Loss
DEB
DET
EN
Detent Enable
SLB
DET EVEN
Detent pulse generated during
Even
numbered track crossings
SVA
DET ODD Detent pulse generated during Odd
numbered track crossings
SVA
DISK SEL
Disk Select (decode signal)
Controller
DLY
SK
Delay
Seek
SLB
EOT
End
of
Travel pulse
Detent
Amplifier
board
FIDX
Fixed Disk Index pulse
DCB
FSTR Fixed Disk Sector pulse
DCB
FWD Forward; direction
of
Positioner movement
SLB
HD SEL
Head
Select (decode signal)
Controller
I
LL
ADD
Illegal Address decode signal
SLB
NAR
New Address Register
SLB
RDY
Ready signal
to
Controller
CIB
RDYINH
Ready
Inhibit
SVA
RIDX
Removable Disk I ndex pulse
DCB
RSTR Removable Disk Sector pulse
DCB
RTZ
Return
To
Zero
DCB
SAC1-16
Sector Address Count
CIB
SK
Seek
CIB
SKC, SK COMP
Seek
Complete
CIB
SKINC
Seek
Incomplete
CIB
SP
DET,
SP
DETEC
Speed
Detect
DCB
STR
Sector
CIB
TC DAC
Temperature Compensation Digital-to-Analog
SLB
TCV
Temperature Compensation Voltage
SVA
TRK
OFFSET Track Offset
Controller
UN LD (L)
Unload
(low
active)
SLB
2-7
Page 33
SUPER SERIES
I/O
BOARD
TERMINATOR
BOARD
1294-001
I/O
CONNECTOR (J-22)
DAISY
CHAIN
CONNECTOR
(J-23)
Figure 2-4. Rear
Panel
and
I/O
Connector 90ard
2-8
Page 34
2.4.3
ELECTRICAL
CHARACTERISTICS
2.4.3.1 Line Receivers.
All
line receivers
within
the drive
are
of
high noise
immunity-type
8T380
or
8836.
All
incoming lines
are
terminated
with
110 ohms
to
4.0 V.
2.4.3.2
Line Drivers. The line driver
circuit
used
in the drive
is
of
the open collector-type.
I n a daisy chain configuration, all
output
lines
are
terminated
within
the system at the last drive
on the chain
to
minimize line reflections due
to
unterminated stubs. The driver
is
capable
of
sinking
50
mA
in addition
to
that
used
within
the disk drive.
2.4.3.3
Terminating Voltage. Provision
is
made
to
terminate all lines
to
an
externally supplied
voltage.
2.4.3.4 Logic Levels. Logic
"0",
within
the drive,
is
defined
as
a level between 0 and 0.5 V.
2.4.4
INPUT
LINES
All
input
lines
are
defined
as
being true (active) when at logic
"0"
level.
2.4.4.1
Cylinder
Address. Eight (nine on
200
TPI) lines which accept
an
absolute address
from
the controller. These
are
strobed
into
an
address register
by
the Cylinder Address Strobe
Line.
2.4.4.2
Cylinder Address Strobe. One line which strobes the Cylinder Address lines
into
the
internal address register.
2.4.4.3
Restore. One line which
causes
the drive
to
reposition the
heads
over
cylinder
"0".
2.4.4.4
Disk Select. One line which selects the disk upon which the
controller
will
operate.
2.4.4.5
Head
Select. One line which selects the disk surface
to
be
operated upon.
2.4.4.6 Write Gate: One line which turns on the
write
amplifier
and
allows current
to
flow
in the selected head.
2-9
Page 35
2.4.4.7
Erase
Gate. One line which turns on the
erase
amplifier. No internal delay
is
pro-
vided
to
compensate
for
the distance between
erase
and read/write
gaps.
2.4.4.8
Write Data. One line which carries the double frequency encoded data
from
controller
to
drive.
Each
pulse on this line
will
cause a flux
reversal
to
occur. Time delay
from
leading
edge
of
Clock pulse
to
leading
edge
of
Data pulse must
be
200
±5
tls (2400 rpm);
320
±5
ns
(1500 rpm).
If
the N RZ
option
is
chosen, (required
for
4400
BPI) this line
will
carry the data in level format,
and
the double frequency
or M FM
encoding
will
be
done
within
the Drive.
2.4.4.9
Read
Gate. One line which enables the
Read
Data and
Read
Glock lines.
2.4.4.10 Track Offset Fwd. (Available on 200 TPI Only). One line which
causes
the
heads
to
move 1/10 track.
2.4.4.
11
Track Offset
Rev.
(Available on 200 TPI Only). One line which
causes
the heads
to
move 1/10 track.
2.4.4.12
Unit
Select.
Four
lines
used
in conjunction
with
the
Unit
Select Switch which allows
any drive
to
be
given any
of
four
logical
addresses.
2.4.5
OUTPUT
LI N
ES
All
outputs
are
defined
as
being true when containing logic
"0."
All
lines gated
with
Unit
Select
except
Attention.
2.4.5.1
Ready. When true, this line indicates drive
is
ready
to
accept external commands.
2.4.5.2
Seek
Complete. When true, th
is
line indicates drive
has
completed a
Seek
operation.
2.4.5.3
Address Acknowledge. When true, this line notifies the
controller
that a Seek
oper-
ation
has
commenced.
2.4.5.4
:Seek
Incomplete. When true, indicates a
Seek
operation
has
not
been
completed in
a predetermined time.
2-10
Page 36
2.4.5.5
Illegal Address. When true, indicates
an
invalid address
has
been
issued
by
the con-
troller. The drive
will
not
obey
such
a command, and the
heads
will
remain positioned over the
previously addressed location.
2.4.5.6
Attention.
Four
lines
not
gated
with
Unit
Select which alert the
controller
that
the
corresponding drive
has
completed a
Seek
operation (when true).
2.4.5.7
Read
Data. One line which transmits the
Read
Data
to
the Controller. The data
format
is
optional and selected
by
jumpers
within
the Drive.
2.4.5.8 Data Clock. This line transmits the
Read
Clock which
has
been
separated
from
the
data.
If
the N RZ
option
is
selected, this line also transmits the \I\/rite Clock
from
the drive when
the
Read
Gate
is
false.
2.4.5.9 Index
Pulse.
This line supplies one pulse
for
each
disk revolution. The pulse
is
derived
from
the physical notch on the cartridge hub,
or
a similar notch on the fixed disk hub. This hub
is
selected
with
Disk Select.
Optionally,
when the internal sector counter
is
not
specified, the user
may specify
two
index lines. I n
that
case,
both index marks
are
supplied simultaneously, and
they
are
not
selected
by
Disk Select.
2.4.5.10 Sector
Pulse.
This line supplies one pulse
for
each
notch on the cartridge hub; or,
for
the fixed disk hub, one pulse
for
every
nth
notch (n = 1
to
16 selected
by
switches on the Disk
Control Board). The hub
is
selected
with
Disk Select.
Optionally,
two
lines may
be
supplied
as
indicated
ill 2 ..
4.5.9.
2.4.5.11
Sector Address. Five lines which define, in binary form, the particular sector under
the Read/Write Head. The Sector Address Counter
is
reset
to
zero
by
the
first
sector mark fol-
lowing the index mark.
2.4.5.12
Pseudo Sector Mark. One line which provides 2000
±20
pulses per revolution
to
the
Controller. This line may
be
used
to
subdivide the disk
into
any number
of
sectors.
2.4.5.13
Write Protect Status. One line which indicates,
to
the controller, the status
of
the
Write I
nhibit
Switch pertaining
to
the selected disk.
2-11
Page 37
2.4.5.14
Write Check. One line which indicates
that
a \I\jrite Operation may
not
take place due
to
one
of
the
following
conditions:
A. Voltages below specified levels.
B.
More than one head selected.
C.
Disk
speed
out
of
tolerance.
D.
Write Gate true and no Write
or
Erase
Current.
E.
Write Current and no Write Gate.
F.
Erase
Current and no Write
o.r
Erase
Gate.
G.
Erase
Gate and no
Erase
Current.
2.4.5.15 200 TPI Status. One line true
if
drive
is
selected
and
a switch on the
I/O
connector
board
is
set
to
indicate
200
TPI.
2.4.6
RACK-MOUNTED
INSTALLATION
The Disk Drives
are
equipped and shipped
with
standard cabinet slides; therefore, installation in a
standard rack involves
only
mounting
the stationary slide members. The
I/O
Connector Board,
the
AC
power cord receptacle, and the AC fuse holder
are
mounted on the rear panel. The panel
is
bolted
to
the stationary members
of
the slides
as
shown in Figure 2-5. Therefore, this panel
will
remain at the rear
of
the rack
or
cabinet when the Disk Drive
is
pulled
out
on its slides. A
flexible
flat
cable assembly, internal
to
the Disk Drive, provides the
I/O
line connections between
the
I/O
Connector board
and
the Disk Drive. Similarly, a spiral-wound AC cord provides the power
connection. These features facilitate unrestricted
access
to
the
unit
without
disrupting internal
connections.
The
mounting
dimensions
for
the
SF
and ST Disk Drives
are
shown in Figure 2-5. The
unit
should:
be
installed in a standard rack
or
cabinet in accordance
with
the
information
shown.
When
only
one person
is
available
to
mount
the Disk Drive in the rack,
it
will
be
necessary
to
install the slide members
(see
Figure 2-5) on the rack first. Then, the Disk Drive
can
be
lifted
into
position and slid
into
place on the slider inside the rack.
NOTE
Head
alignment, after rack installation,
is
not
guaranteed. Read!Write
head
alignment should
be
accomplished,
as
outlined in Section 5,
after
rack installation.
2-12
Page 38
J}-7---11
)
°\1"
24.ooIN.
(60.96 CM)
(SEE
NOTE
2)
/
~
I
-!:80:/~M)-
--r
22.00 IN.
(5588
CM)
1113-001
_
ISEE
rTf
11
TYPICAL
MOUNTING IN
EIA/RETMA
CA81NET
TOP
PROPE
RTY
LINE
! 0.500 IN
---r--
--
--'-~========~
:~~~;~~S)
F 7.00 IN. (17.78 CM)
~
!
~
1-+---(55.88
CM)-
22.00 IN. I
I'
_T_7_'7_57tIN~t_(1_9'6_9CM=\~t~~~~~~~==~~~~-=-r-=-~-~--Jrt
_18.31
IN. _ 0.625 IN
NOTES:
(CLOSED) 46.00 IN.
(116.84 CM) •
(OPEN)
BOTTOM 0.875 IN.
(46.51 CM) (1.5B8 CM)
PROPE
RTY (1.223 CM)
(4
PLACES)
LINE
(4
PLACES)
(1)
IF
30.00 IN.
(7620
CM) DEEP
CABINET
IS
USED. POSITION REAR RETMA BOLT
RAILS
22.00 IN. TO 23.00 IN. (55.88
CM
TO 58.42 CM) BEHIND FRONT RAILS.
(2) SLIDE
MOUNTING
BRACKETS ARE
NORMALLY
MOUNTED
ON
EXTERIOR SIDE
OF CABINET.
Figure 2-5. Rack-Mounted Installation Instructions
2-13
Page 39
2.4.7
INITIAL
CHECKOUT
2.4.7.1 Preliminary Procedure.
After
the Disk Drive
has
been
installed and connected
to
the
external
Controller, all
I/O
cables should
be
rechecked
to
ensure correct connections. Make certain
all connectors
are
mated securely and
that
the correct voltage
is
being supplied
to
the Disk Drive
before the
unit
is
installed in the rack. The
top
cover
of
the Disk Drive must
be
removed
to
gain
access
to
subassemblies
to
be
checked during
initial
checkout procedures. Procedures
for
removing
the
top
cover
are
outlined
in Section
5.
2.4.7.2
Visual
I nspection. Make the
following
checks before applying power
to
the Drive.
A. Ascertain
all plugs and connectors
are
properly
seated except P16 (Power
Supply) which must remain disconnected when using a (C.E.) test hub.
B.
Check
for
proper
fuses.
C.
Check card
cage
to
ensure printed
wiring
boards
are
properly seated.
2.4.7.3 Preliminary
Power-On Procedure.
VVith
the
top
cover removed and using a customer
engineer
(C.E.) test hub, the
top
cover interlock switch
will
not
be
activated. Power cannot
be
applied
to
the Spindle Drive
Motor.
I n the
SF
unit,
this
is a button-type
switch
protruding
from
the
base.
Place
a piece
of
masking tape over the switch. I n the ST
unit,
install a matchbook cover
(or simi
lar device) between pack sensor and switch actuRt,or.
See
Figure 2-6.
2.4.7.4
sequencing:
l~
ENSURE PLUG P16
ON
THE
POWER SUPPLY
IS
STILL
DISCONNECTED.
THIS
WILL
PRE-
VENT
HEADS FROM
LOADING
WHEN
USING
THE
(C.E.) TEST HUB.
Power-Up Sequence Check. Perform the
following
steps
to
verify
proper power-up
A.
Place
POWE
R switch ON.
B.
Verify
that
the
door
unlocks and
that
POWE
R and
LOAD
indicators light.
C.
Place
the
RUN/LOAD
switch
to
RUN.
D.
Verify
that
the
LOAD
indicator
extinguishes,
door
locks, and the spindle begins
to
spin
CCW.
E.
Verify
that
brushes
sweep
the disk once, then park underneath the receiver. The
brushes should
not
be
crushed against the casting.
F.
A
sl
ight fl ickering
of
control
panel indicator lamps indicates spindle
speed
control
circuitry
is
active.
If
a problem occurs, power
down
the Drive and refer
to
appropriate part
of
Section 5.
2-14
Page 40
figure
2-6. By_passing
lOP
cover
InterloCK
2-15
switch
Page 41
Page 42
SECTION 3
OPERATION
3.1
This section provides
Loading (ST) Disk Drives. Description
operational commands
3.2 OPERATOR
Operational controls
Drive. Some
translucent engraved
functions
SUPER
SCOPE
information
used
CONTROL
and
status indicators
of
the controls feature integral indicator lamps which,
control push buttons. The control cluster
of
the controls and indicators
SERIES
by
the
for
unit
operation
of
front-panel controls and indicators
are
PANEL
are
are
described in paragraphs 3.2.1.1 through 3.2.1.6.
of
included.
mounted
the Super Series
on
a panel located on the
is
shown in Figure 3-1, and individual
Front
Loading (SF) and
and
if
activated, illuminate the
a summary
front
of
the Disk
11158-001
of
Top
the
o
o
R
READY
LOAD
~
PROT
FIXED
Figure 3-1. Operator Controls
3-1
o
o
Page 43
3.2.1
FUNCTIONS
OF
OPERATOR
PANEL
CONTROLS
3.2.1.1
When
The
the
lamp inside
position.
3.2.1.2
RUN.
When
rotating
the
Drive
the
and
Disk
can
cabinet,
3.2. 1.3
upper
portion
operator
Commands
is
notified
Power
switch
Run/Load
the
the
is
stopped
be
opened
and
Ready/Load
of
is
aware
from
that
Switch/Indicator.
is
pressed
the
switch
Switch.
upper
part
Read/Write
and
the
or
the
the
removable
Indicator.
the
lens
is
that
the
the
external
the
spindle
upward,
lights
and
This
of
the
switch
heads
Disk Drive
lock
on
disk
cartridge
marked
cycle
has been
Controller.
has
stopped
This
is a two-position
line
power
remains
is
lit
is a two-position
is
depressed,
loaded.
an
Th
VVhen
is
in
Load
ST
Disk Drive
can
is is a status
READY.
be removed.
When
completed
When
the
rotating.
applied
until
rocker
the
lower
mode.
is
indicator
the
LOAD
At
this
to
the
the
switch
switch
the
Disk Drive
(LOAD)
At
this
unlocked
incorporating
READY
and
the
portion
time,
switch/indicator
Disk Drive integral
is
placed
whose
time,
so
is
part
that
the
the
upper
in
Run
of
front
the
chassis
a divided lens cap.
portion
unit
of
the
removable
is
the
able
switch
of
to
the
accept
disk
marked
power
in its
position
mode
switch
door
can
switch
lights,
cartridge
POWER.
supply.
OF F (down)
is
marked
with
the
disk
is
depressed,
of
an
SF
Disk
slide
out
of
The
lights,
Seek
the
the
or
Data
operator
can
be
loaded
or
unloaded.
3.2.1.4
rocker
I
nhibit
switch
written
switch
circuits.
also lights. When
on
the
3.2.1.5
marked
Write
PROT
Inhibit
also will light.
I
nhibit
circuit
3.2.1.6
3.
When
assigned
the
to
the
Protect
marked
At
cartridge
Protect
FIXE
circuits
When
is
inactivated.
Unit
Select
switch
Disk Drive
Cartridge
PROT
this
time,
the
disk.
Fixed
D.
When
and
data
the
lower
Switch.
is
set
to
for
(Disk)
CART.
data
switch
(Disk)
the
can
area
any
the
Switch/I
When pressed
can
not
be
is
depressed
Switch/Indicator.
upper
'This
purpose
area
of
not
be
written
of
the
switch
is a thumbwheel
of
these
four
of
external
ndicator.
upward,
written
downward,
This
the
switch
on
is
depressed,
active
control.
This
switch/indicator
the
switch
on
the
cartridge
the
lamp goes
is a two-position
is
pressed,
the
fixed disk.
the
switch
with
activates
disk.
rocker
the
switch
The
lamp
will go
respective
The
out
activates
lamp inside
markings
positions, a corresponding
is a two-position
associated
lamp
and
data
Write
inside
can
the
be
switch/indicator
associated
the
switch
out
and
the
Write
0, 1, 2,
logical
and
address
is
3-2
Page 44
3.3
CARTRIDGE
LOADING
3.3.1
SF
DISK
DRIVE
The cartridge
used
in the
SF
Disk Drive
is
the
iBM
2315-type. Before the cartridge
can
be
inserted,
AC power must
be
applied
to
the
unit.
Removable cartridge loading
for
both
SF
and
ST
is
shown
in Figures 3-2 and 3-3. This enables the safety interlock mechanism
to
be
released
and the loading
door
at the
front
of
the Disk Drive
can
be
opened. The turn-on
and
loading sequences
are
dia-
grammed on the
flow
chart in Figure 3-4.
DO
NOT
ATTEMPT
TO FORCE OPEN THE
DOOR BEFORE AC POWER HAS BEEN
APPLIED TO
THE
DISK
DRIVE
OR THE
DOOR ASSEMBLY
MAY
BE
DAMAGED.
WHEN
THE
POWER
AND
LOAD
INDICA-
TORS ARE I
LLUMINATED,
THE
INTER-
LOCK
IS
RELEASED
AND
THE
DOOR CAN
BE
OPENED EASI LY.
NOTE
The 2200 and
4400
BPI
cartridges
are
keyed
differently.
To
load the cartridge, perform the
following
steps:
A.
Apply
power
to
the Disk
Drive
by
pressing the
POWE
R switch. Observe
that
the
lamp inside the
switch/indicator
lights.
B.
When the
LOAD
indicator lights, pull the loading
door
forward and down. The
cartridge receiver should then
be
elevated and moved
to
a position in which
it
can
accept the cartridge.
C.
Orient the cartridge
so
that
its head
entry
opening
faces
the
interior
of
the drive
(12
o'clock
position).
D.
Push
the ,disk cartridge
into
the receiver.
3-3
Page 45
1116
Figure 3-2. SF Disk Drive Cartrldge Loading
3-4
Page 46
Figure 3-3. ST Disk Drive Cartridge Loading
3-5
Page 47
1117-001
BEGIN
COMPUTER
OPERATIONS
REMOVE
CARTRIDGE
INSTALL
CARTRIDGE
INCORRECT
PROPER JOB
YES
YES
TURN
SWITCH
RUN/LOAD
TO
LOAD
Figure 3-4. Operating the SF or ST Disk Drive
3-6
Page 48
E.
When the disk cartridge
is
almost
fully
inserted in the receiver,
it
will
reach
a
preliminary stop at the
point
where the wire bail opens the small
entry
door
in
the cartridge. Continue
to
push the cartridge
into
the receiver
until
it
comes
to
a final stop.
F.
The loading
door
can
be
closed and the start cycle
can
be
initiated.
3.3.2 ST
DISK
DRIVE
The cartridge
used
in the top-loading ST Disk Drive
is
the IBM 5440-type
(see
Figure
3~3).
To
load
the cartridge, perform the
following
steps:
A.
Apply
power
to
the Disk Drive
by
pressing the
POWE
R switch. Observe
that
the
lamp inside the
switch/indicator
lights.
B.
When the
LOAD
indicator
lights, pull the Disk Drive
out
of
the rack; its loading
door
should open automatically
as
the
unit
slides out.
C.
Before the cartridge can
be
inserted, its
bottom
cover must
be
removed.
Raise
the cartridge handle
to
a vertical position while pushing the
release
button
side-
ways,
D.
The
bottom
cover
is
then
released
and
can
be
remdved.
It
will
be
installed later
on
top
of
the cartridge.
E.
Orient
the cartridge
so
that
the cartridge logo
or
letters
are
facing the
front
of
the Disk Drive. The cartridge
is
keyed and may
be
installed
only
if
oriented
correctly.
F.
Lower the cartridge
into
the shroud and make certain
it
is
seated
firmly
on the
shroud.
G.
Fold the cartridge handle down. This action unlocks the cartridge
release
button.
H.
I nvert the
bottom
cover and place
it
over the
top
of
the cartridge.
NOTE
The cartridge MUST
be
installed
as
described
or
the start cycle can
not
be
initiated.
J. Close the locking
door
by
pushing the Disk Drive back
into
the rack. The
Start
cycle can then
be
initiated.
3-7
Page 49
NOTE
In both the
SF
and
ST Disk Drives, the loading
door
remains locked
if
the
POWE
R switch
is
pressed
downward while in the RUN mode;
therefore, the cartridge
can
not
be
removed.
If
this occurs, the Disk Drive must again
be
placed in the Load mode,
with
power applied,
to
enable the loading
door
to
be
unlocked.
3.3.3 OPERATING THE
DISK
DRIVE
The controls on the Operator Control
Panel
(OCP)
of
the
SF
and
ST Disk Drives
are
identical and
there
is
no difference in operating the
two
types
of
Disk Drives.
3.3.3.1
Power On and Load Status. When AC power
is
supplied
to
the Disk Drive,
two
events
should occur:
A. Power and Load indicator lamps should light.
B.
The loading
door
should unlock.
At
this time, the removable cartridge may
be
removed from,
or
inserted into, the Disk Orive.
NOTE
Inspect the cartridge
for
dirt
or
contamination
before installing in Disk Drive.
3.3.3.2 Establishing the Ready Status
from
the Load Status.
To
initiate this operation, transfer
the
RUN/LOAD
switch
from
LOAD
position
to
RUN position. The
following
events should then
occur:
A. The loading
door
should lock.
B.
The disks should come up
to
operational
speed.
C.
The disk brushes should
go
through
their
cleaning cycle and return
to
their
home
position.
D.
The positioner should move forward and load the
heads
at track 000.
E.
The
READY
indicator should
light
after the cartridge
has
warmed up.
3-8
Page 50
Ready status
is
then established and the Disk Drive should respond
to
external commands
from
the
Controller.
NOTE
A customer
option
provides cartridge
protect
light
illumination
and inhibits
writing
until
full
temperature stabilization
has
occurred.
3.3.3.3 Establishing Load Status
from
Ready Status.
To
initiate
this operation, transfer the
RUN/LOAD
switch
from
the RUN position
to
the
LOAD
position. The
following
events should
occur:
A. The
READY
indicator
should
go
out.
B.
Disk
rotation
should gradually decrease
until
rotation stops.
C.
The
LOAD
indicator
should
light
(approximately 15 seconds).
D.
The loading
door
should unlock.
At
this time, the cartridge may
be
removed and replaced,
or
power
to
the Disk Drive may
be
re-
moved.
NOTE
When the cartridge
is
removed
from
an
ST Disk
Drive,
it
should
be
placed in its cover immed-
iately
to
preclude damage
to,
or
contamination
of,
the cartridge. On
an
SF
Drive, the cartridge
should
be
stored in a clean environment
and
handled in a manner
that
will
not
damage any
of
the critical parts
of
the cartridge.
3.3.3.4 Operator Maintenance. Before installing a cartridge
into
the Disk Drive, inspect the
cartridge
for
contamination. On the
SF
and ST Disk Drives, inspect the spindle chuck and shroud
for
contamination.
For
cleaning techniques and frequency, check
with
the local customer service
representative.
3-9
Page 51
WHEN INSERTING A REPLACEMENT CAR-
TRIDGE
IN THE
DISK
DRIVE,
MAKE
CER-
TAIN
THE
CARTRIDGE
HAS BEEN IN THE
SAME
AMBIENT
CONDITIONS
AS
THE
DISK
DRIVE
FOR A
MINIMUM
OF 2 HOURS.
IF
THIS
PROCEDURE
IS
NOT FOLLOWED,
WARM-UP PROBLEMS
MAY
BE
ENCOUNT-
ERED
ON
200 TPI UNITS.
3.3.4
TIMING
Figure 3-5 shows typical
timing
relationships encountered during the Disk Orive Power
On/Off
timing
sequence. I n this figure, a high level indicates the
true
or
on state
of
the particular function.
1118-001
POWER
SWITCHLITE
LOAD
INDICATOR
RUN/LOAD
SWITCH
READY
INDICATOR
SEEK
COMPLETE
~~----------------~t~~------------------~
____
_
-..j
r-
APPROXIMATELY 5 SEC
--~I
-I----------~t~t--------~I
---.l
25
SEC
\.----
__
--.:-1
----I
t
r-1
-j
r--
SEE
NOTE 1
--------rll
.....
_____
I U:---,
...
_________
_
--------~l~~~-------------------
NOTE
1:
ELAPSED TIME
IS
DETERMINED BY THE TIME
IT
TAKES FOR A
TEMPERATURE
MATCH TO OCCUR BETWEEN BASEPLATE
AND
CARTRIDGE DISC.
F igu
re
3-5. Power
On/Off
Sequence
3.3.5
TEMPERATURE
CHARACTERISTICS
When operating
the
Disk Drive, the casting temperature near the location
of
the temperature sensor
is
controlled
to
within
100F (5.50C)
of
ambient.
If
a cold cartridge
is
placed in a drive in which the
unit
has
been operating, the difference in temperatures
will
inhibit
transfer
to
the ready state,
with
associated lighting
of
the
READY
indicator,
until
the
two
temperatures
are
approximately equal.
3-10
Page 52
3.4 FLOW CHARTS
Flow
charts
of
modes, cycles,
and
operations
NO
AC
POWER
DC
ELECTRONICS
are
shown in Figures 3-6 through 3-12.
AC
POWER
AVAILABLE
POWER
POWER
IS
AVAILABLE
SUPPLY
AVAILABLE
TO
DRIVE
TO
TO
0418
Figure 3-6. Power-up
LOAD
LIGHT
LATCH ASSEMBLY ACTUATES
ON
REMOVE/REPLACE
CARTRIDGE
and
Cartridge Loading (Load Mode)
NO
Page 53
NO
NO
NO
NO
POWER
UP
SEQUENCE COMPLETED
POWE
R APPLI
ED
TO
DRIVE
& BRUSH MOTORS
Figure 3-7. Run Mode -
Initial
Cycle
3-12
0420
Page 54
ENABLE
POWER
AMPLIFIER
CARRIAGE
MOVES
FORWARD
NO
FIRST
TRACK
COUNTING
PULSE RESETS
NAR
& CAR
TO
0 & DETENTS
NO
READY
LIGHT
ON
Figure 3-8. Run Mode - Cylinder 000
Seek
3-13
,0417/2
Page 55
COARSE LOOP SERVO
DE·ENERGIZED
FINE
LOOP SERVO
(DETENT)
ENERGIZED
0419
COMMAND
IGNORED
ISSUE
ILLEGAL
ADDRESS STATUS
UNIT
IS
OPERATIONAL
ADDRESS
DATA
COMMAND
ADDRESS
INTO
NAR
AND
SK INCOMPL
DIRECTION
INFORMATION
BY
SERVO
IS
AND
START
SENT TO
SEEK
BEEN ISSUED
CYLINDER
STROBED
SEEK PULSE
400
MS
YES
NEW ADDRESS COMPARED
WITH CAR
VELOCITY
GENERATED
ELECTRONICS
POSITIONER
HAVE
IS
BY
TIMER
START 5 MS
COMPLETE
A
SEEK COMPLETE ISSUED
YES
&
SEEK
TIMER
NO
YES
SEEK INCOMPLETE
ISSUED
CARRIAGE
TO
RETURNS
TRACK
"0"
NEXT
SEEK PULSE
RESETS SEEK
INCOMPLETE
LINE
Figure
3-9.
Run
Mode
3-14
- New
Address
Seek
Page 56
YES
NO
YES
0416
YES
YES
NO
Figure 3-10. Run Mode - Write Operation
3-15
Page 57
UNIT
SELECTED
DISK SELECTED
READ
DATA
SUPPLIED TO
DATA
DISCRIMINATOR
READ
OPERATION
COMPLETE
0421
NO
Figure 3-11. Run Mode -
Read
Operation
3-16
Page 58
FILE
OPERATIONAL
READY
LIGHT
OFF
CARRIAGE
RETURNS HOME
LOAD
LIGHT
ON
INTERLOCK
OPENS
REMOVE/R EPLACE
CARTRIDGE
NO
NO
Figure 3-12.
Turn-off
Cycle
3-17
~422/2
Page 59
Page 60
SECTION 4
THEORY
OF OPERATION
4.1
INTRODUCTION
In
general electronic theory, 100
and
200 TPI
SF
and
ST
Disk Drives
are
basically identical.
Throughout this section
only pertinent differences will
be
pointed out. Data recording
or
retrieval
method
is
double frequency-encoded, except in the
case
of
the 200 TPI 4400
BPI
option, which
is
modified frequency modulation (MFM).
4.2
SCOPE
This section
is
divided
into
two
principal parts: mechanical description
and
electronic theory.
T~e
mechanical part
is
sub-divided
into
two
areas;
Spindle/Drive
Motor
Assembly
and
Positioning
f:\ssembly. The electronic part
is
further
sub-divided
into:
System Electronic Theory, Logic Board
Circuit
Analysis,
and
Schematic Diagram Analysis. The simplified block diagram
for
the Disk
Drive
is
shown in Figure 4-1.
4.3
MECHANICAL
DESCRIPTION
4.3.1
SPINDLE/DRIVE
MOTOR ASSEMBLY
The spindle drive
motor
is
combined
into
an
integral assembly,
as
shown in Figure 4-2. The spindle
is
directly
driven by a
DC
brushless motor.
Speed
is
held constant
to
with,in ±
1%,
regardless
of
line
voltage
or
frequency fluctuations. The blower drive
belt
and
pulley assemblies
are
shown in Section
5,
Figure 5-5. Static eliminators
are
included on both the spindle
and
blower shafts
to
dissipate
electrical noise. The blower
and
its associated
filter
provide a constant
flow
of
cool, clean air
to
the unit.
4-1
Page 61
SPINDLE
LIMITER
BOARD
MOTOR
DRIVE
POWER
SWITCH
BOARD
I
t
BRUSHES
TO DEB
READ/WRITE
HEADS
INDEX/SECTOR
TRANSDUCER
POSITIONER
TRANSDUCER
-------
,--
ELECTRONICS
INTERCONNECT
BOARD
(MOTHER
BOARD)
SERVO
AMPLIFIER
BOARD
(SVA)
FROM
READ/WRITE
HEADS
DATA
ELECTRONICS
BOARD
(DEB)
SERVO
LOGIC
BOARD
(SLB)
CONTROL
INTERFACE
BOARD
(CIB)
DATA
INTERFACE
OR
MFM
BOARD
(DIB) OR (MFM)
Figure 4-1. Simplified Block Diagram
4-2
--,
I
I
I
I
I
I
I
1119-001
I/O
1
...
-_
..
- CONNECTOR
1-
-
BOARD
I (lOB)
I
I
I
I
I
I
---I
"
TO
EXTERNAL
CONTROLLER
Page 62
0203·001
DISK~
FIXED
SECTOR RING W/SLOTS
DISK
SPINDLE
SHAFT
MAGNETIC
RING
Figure 4-2. Spindle/Drive
4-3
Motor
Assembly
Page 63
lVIagnetic transducers detect slots machined
of
index and sector pulses. Three types
sector rings
into
the
edge
of
sector rings
are
shown in Figure 4-3. The
from
which
fixed
to
produce
disk ring
is
mounted
disks
has
loading
magnetic transducer. I n all
directly
(front
on the Spindle/Drive
or
top-loading), there
slots machined in the outer
type
has
a lip
that
extends downward. The
cases,
Motor
are
two
edge
in a manner similar
Assembly. Since there
types
the transducers
are
two
types
of
of
cartridge disk sector rings. The top-loading
to
those
of
the fixed disk. The
front-loading
are
positioned
type
so
also
has a different
that
the slots
can
detected.
4.3.2
POSITIONING
The positioning system shown in Figure 4-4 consists
ator), the carriage assembly, and the optical detenting assembly.
move and position the Read/Write heads
by
the servo system which
The Read/Write heads
'Juide rails. Extending
ASSEMBLY
of
three major parts: the linear
All
three parts
to
the proper track on the disk. The linear
is
explained in the electronic
mount
or
on the carriage assembly which rides on ball bearings over precision
retracting the carriage along the guide rails moves the heads radially
theory
portion
of
this section.
motor
are
necessary
motor
across the disk surface. An optical position transducer produces analog signals necessary
cartridge
type
front-
type
of
be
easily
(actu-
to
is
driven
for
moni-
toring
head position and detent operations. This
and reticle assembly. The reticle assembly
of
series
tween the lens and reticle assembly and
The lines on
The arrangement
the solar cells, the
to
provide a
of
the solar cells
to
detect the Beginning
by
etched vertical lines. A matching
each
piece
of
glass
of
these lines
other
is
cut
modified
slots etched on the lower
sine-wave. A null
conduct
equally,
of
Travel (BOT) and End
portion
comprise
is
such
off
as
shown in Figure 4-5. The
is
identified
of
is
mounted on the carriage assembly.
that
point
the movable
unit
contains a
has a PWB
glass,
an
optical grid made up
when
with
photo
with
corresponding lines etched on
maximum
light
(marked X on figure 4-5),
as
the crossing
of
Travel (EOT) pulses. These pulses
glass
as
shown in Figure 4-6.
light
diodes and a
of
alternate dark and
is
allowed
outputs
of
a track. A
emitting
to
of
the solar cells
or
the
point
third
diode
glass
(LED),
mask
it,
moves
light
with
areas.
impinge on one
is
summed
at
which both
solar cell
are
produced
is
lens,
a
be-
of
used
4-4
Page 64
SECTOR SLOT / /
INDEX
SLOT/'
a.
FIXED
DISKSECTOR
RING
SECTOR SLOT
INDEX
SLOT
SECTOR
SLOT
INDEX
SLOT
b.
TOP
LOADING
CARTRIDGE
DISKSECTOR
RING
c.
FRONT
LOADING
CARTRIDGE
DISK
SECTOR RING
WITH
DUST COVERS REMOVED
Figure 4-3. Three Types
of
Sector Rings
4-5
0832-001
RECORDING
SURFACE
Page 65
SUPER
SERIES
CARRIAGE
. Assembly
4 4 Positioner Figure - .
4-6
1093/2·003
Page 66
SUPER SER I
OUTPUT
WAVESHAPE
ES
LED
LIGHT
SOURCE
._--
....
POS.
CH.
112O·oo2B
TOSVA
MOVABLE
OPTICAL
Figure 4-5. Optical Transducer Diagram
CARRIAGE
DIRECTION
..
ETCHED
GLASS
0873·001
_-_-_=1
BOT
Figure 4-6. Movable Optical
4-7
Glass
EOT
Page 67
The
Read/Write heads
"fly"
over the recording
track
with
the clearance ranging
from
80
micro-
inches
(0.002032
mm)
at
the
innermost concentric
track
to
130 microinches
(0.003202
mm)
at the
outermost
track.
The
difference in head clearance
is
due
to
increased surface
speed
at
the
outer
tracks and
causes
increased pressure against
the
heads.
Approximately
two
inches
(5.08
cm)
of
the
disc
area
is
actually used
for
recording data in
both
the 100 TPI and
200
TPI models; however, the
tracks
i~
the
200
TP I model. are spaced
twice
as
close together. I n Read
operation,
the
head picks
up data previously recorded on
the
addressed track. In V\lrite operation,
the
head magnetizes
the
area
directly
below
the
head.
As shown in Figure 4-7, the head assembly contains a Read/Write/Erase core whose center tap
is
energized when
the
head
is
selected
for
either a Read
or
Write
operation.
The
remaining com-
ponents include a ceramic shoe, a head
support
arm which
is
used
to
attach
the
head assembly
to
the
carriage, and a gimbal spring
which
allows
the
head
to
follow
the
disk
contour.
The
use
of
the
mechanical ramp
is
explained in
the
following
paragraph. The
functions
performed
by
circuits
associated
with
the
Read
or
\lVrite operations are included in
the
discussions
of
these
circuits
as
associated
with
the
circuit
analysis descriptions.
The
ReadIWrite heads
are
automatically
unloarled
during
a power-down procedure and are auto-
matically
loaded when
the
R UN switch on
the
Operator
Control
Panel (OCP)
is
actuated.
The
ReadIWrite heads
are
ramp-loaded, a technique requiring
minimal
components
while
retaining
close
control
over rate
of
head load.
The
assembly rides up a mechanical ramp when retracted
and
is
lifted
further
away
from
the
disk surface. Figure 4-8 shows
the
ramp-loaded heads
in
the
unloaded
position.
As the heads move
forward,
they
slide
down
the ramps and are loaded
directly
over
the
surface
of
the
disk.
To
protect
user data
as
well
as
the disk surfaces and Read/Write heads, several safety features have
been designed
into
the
unit.
Voltage sensing
circuitry
constantly
monitors
both
AC and DC oper-
ating voltages.
An
AC
loss
for
the
duration
of
three
or
more consecutive cycles,
or
a DC loss,
would
cause
the
carriage
to
be
retracted
which
would
automatically
unload
the
heads, and
the
spindle
would
begin
to
slow
down.
Circuitry
is
provided
to
automatically
restart
the
Drive
if
the
voltage concerned has returned
to
normal and
the
position
of
the
POWE
Rand
RUN/LOAD
switches has
not
beeen changed.
4-8
Page 68
SUPER
SERIES
CERAMIC
SHOE
BLEED
HOLES
GIMBAL
SPRING
1121-001
RAMP
Figure 4-7. Read/Write Heads
4-9
Page 69
SUPER SERIES
1122-001
SPRINGS
Figure 4-8. Head Unloading Mechanism
4-10
Page 70
4.4
SYSTEM
ELECTRONIC
THEORY
4.4.1
FUNCTIONAL
BLOCK
DIAGRAM
DESCRIPTION
4.4.1.1
100 TPI and 200 TPI Similarities. Since the 100 TPI
and
200 TPI Disk Drives
are
basically similar, the
following
theory
discussion
will
apply
to
both types
of
Disk Drives. Operating
principles
are
identical except
for
the track density achieved in the 200 TPI model by spacing
of
the concentric recording tracks. The 200 TPI
unit
also incorporates temperature compensation
circuitry.
4.4.1.2 I
ntroduction
to
Circuit
Theory. Figures 4-9 and 4-10
are
functional block diagrams
of
the Disk Drive showing interconnecting signals and the functions performed
by
the
circuit
boards contained
in
the
unit.
Figure 4-10
is
for
4400
BPI
machines
only
which
use a Modified
Frequency Modulation (MFM) board in place
of
the Data Interface Board (DI B). These block
diagrams should
be
used
as
a reference when
following
circuit
functions described; in
addition,
the basic block diagram
of
the Disk Drive
can
be
referred
to
(see
Figure4-1). The mechanical
operation
theory
also should
be
used
as
a reference.
4.4.1.3 Basic System Operation. When the
POWE
R switch on the
OCP
is
pressed,
control
circuits, registers, and counters
are
preset
to
a desired initial state. The applicable
DC
working
voltages
are
generated, and the circuits which drive the
DC
spindle drive
motor
are
enabled. Note
that
the Start, Stop, Run/Load mode selection,
as
well
as
activation
of
the Write protection cir-
cuits,
are
made
by
actuation
of
front-panel switches. Conversely, the Seek, Restore,
Read
and \f\lrite
operations
are
initiated
by
the external
Controller
through data,
control,
timing
and
status signals
transmitted through the
I/O
interconnecting cable.
Once the disk rotational
speed
has
reached 1500
or
2400-rpm nominal value specified
by
the
customer, the Read/Write heads
are
loaded automatically.
At
this time, the positioner carriage
on which the
heads
are
mounted
is
driven
from
its Home position
to
track 000. When the heads
have settled over this track and
READY
INHIBIT
has
been
disabled, a
READY
status signal
is
sent
to
the Controller.
4-11
Page 71
r---,
I
\
\
I
I
I
I
I
I
I
I
I
I
I
I
EXTERNAL
\
CONTROLLER
\
I
I
I
I
I
I
I
I
\
\
\
\
I
I
I
I
INITIATES,
MONITORS,
&
TERMINATES
ALL
READ/
WRITE FUNC·
TIONS.
I
I
I
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ADD1~266
- -
Lij"j:i'ij
~
RESTORE
CLR STROBE
SEEK STROBE
SEEK STROBE
-
Er
,-
EN
DR
OUTPUT
DRIVERS
I
I
I/O
UNIT
SELECT
I
DECODER
L I
UNIT
(4
LINES)
I
SELECT
~
L_
I
SWITCH
iJ'iHi)
RUN
H
l~
CARTRIDGE
I/O
INTERLOCK
CONNECTOR
(lOB)
&
RUN/LOAD
(LINE
RECEIVERS)
-:-
..::.!!!......
SWITCHING,
INDEX/SECTOR
TRANSDUCER
INDEX/SECTOR
67~KM
-
.....
(REMOVABLE
DISK
INDEX/SECTOR
67s°KM-
....
TRANSDUCER
INDEX/SECTDR
-
(FIXED DISK)
HEAD SELECT
DISK SELECT
WRT CHECK X
DISK SELECT
HEAD SELECT
DATA
CLKIWRITE CHECK X
WRITE GATE
WRITE GATE
WRITE
DATA
WRITE
DATA
READ ENABLE
READ
EN
GATE
-
-
SERVO
LOGIC
BOARD
(SLB)
CONTAINS CYLINDER
ADDRESS REGISTER AND
GENERATES A
SIGNAL
PROPORTIONAL TO
THE
NUMBER
OF
TRACKS THE
HEAD
POSITIONER
HAS
TO
MOVE. ALSO CONTAINS
SOME
TEMPERATURE
COMPENSATING CIRCUITRY.
- ADD 256/128
TEMPERATURE
SENSOR
SENSES
TEMPERATURE
OF
BASE
CASTING
AND COMPENSATES HEAO
POSITION
AS
REQUIREO.
TCV
IDCB}---------
TCOAC
BEGINNING
OF
TRAVEL
PULSE
FWD/REV
EN
IL}
LOAD/UNLOAD I+}
DIF.
256/128
I-I
'"
o DAC
SERVO DET
EN
(-)
FWDH
ODD
(+)
DETENT ODD
(-)
DETENT EVEN
(-)
FWD
INHIBIT
DIFF 1 IL}
RETRACT
DATA
ELECTRONICS
BOARD
A~ ~R
5~
[<:i~~
SERVO
I
AMPLIFIER
-
DISK
CONTROL
BOARD
(DCB)
CONTROLS DISK
OPERATION
AND
SPM
ON
MAINTAINS DISK
SPEED
CONSTANT.
SEPARATES INDEX
AND
SECTOR
PULSES.
CONTROLS
HEAD LOAD/
BM
ON
H
UNLOADING
SOL
;
i
J
DOOR
LOCK
SOLENOID
-
WRT INHIBIT
DATA
SP
DET
ISPEED
DETECT}
INTERFACE
WRITE
BOARD
(DIB)
WRITE
DATA
X
SUPPLIES DOUBLE FREQUENCY
ENCODED WRITE
DATA
FROM
THE CONTROLLER
TO
THE
DATA
ELECTRONICS CIRCUITRY.
ERASE
DATA
CLOCK
ADD 256/128
-
--
(FROM SLB)
Figure
4-9.
Block
Diagram -Supe-r
Series
(major
signal
lines)
(sheet
1 of
2)
4-12
Page 72
..
-
--
~t;tTRONICS
....
_____
......:(:.4
:::LI~NE:::S:.:../H::.EA~D:.:.)
____
---.
0386/2
BOARD
BEGINNING
OF
TRAVEL
PULSE
POSITION
-
TRANSDUCER
AGC
t
WRITE
DETENT
PULSE
GENERATES POSITION
~
INFORMATION
AS
WELL
LIGHT
SOURCE
AS
HOME & DETENT
FOR
OPTICAL
SIGNALS,
READ
LAMP VOLTAGE (lOV)
DETENT
ASSY.
SERVO
TRANSFERS LIGHT
AMPLIFIER
TO
PHOTOCELLS
TO
GENERATE DETENT
DC
LOSS
BOARD
(SVA)
SIGNALS,
POSITIONER
........
..
THE MAIN FUNCTION
OF
THE
(MOTOR DRIVE)
SERVO AMPLIFIER
IS
TO
DRIVE
THE SERVO MOTOR,
IT ALSO
SUMS
THE VELTACH
SIGNAL WITH EITHER THE
INPUT FROM THE COARSE
OR
FINE SERVO
LOOP
FOR HEAD
·
POSITIONING,
·
RDY INH
·
(VELOCITY DATA)
DETENT
EN
TRK OFF
SET
·
DT
EN
(DETENT ENABLE HIGH)
DLY
SK
-
ILL
ADD
..
SK
(SEEK)
CLR STROBE
SEEK STROBE
-
--
RETURN ZERO
PSEUDO
SECTOR
2000
RDYl
P
DC
LOSS
~
~
F
SECTOR
F INDEX
~
...
R
SECTOR
R INDEX
.
'''ND''
DmV'
~
LIMITER
MODULE
'
AND
POWER'
SPINDLE
SWITCH
MOTOR
PROVIDES SPINDLE
MOTOR
CURRENT
TO
+
R/w
....
-.,
~r
HEADS • SPINDLE
TO
INDEX/
J----DISKS_+_
~
SECTOR
TRANSDUCERS
BRUSH
--I
BRUSHES
I
MOTOR
WRTCHKX
I 1
DISK SELECT
t t I
DATA
READ
DATA
1
ELECTRONICS
READ
DATA
2
BOARD
(DEB)
-
...
PROCESSES
I/O
DATA
FROM/TO
THE CONTROLLER, IN SEPARATE
READ/WRITE CHANNELS,
DATA
CLOCK
PROVIDES WRITE PROTECT LOGIC
TO
ENSURE
DATA
IS
NOT ERASED
INADVERTENTLY,
READ ENABLE
ALSO
REGULATES±
13V,
I
_WRITE~
READ/WRITE HEADS
~READ
(4
LINES)
MOTOR
----
POSITIONS
READ/wRITE
HEADS
VELOCITY
TRANSDUCER
SENSES
VELOCITY
OF
POSITIONER MOTOR
AND
REPORTS
INFOR·
1
MATION TO SERVO
AMPLIFIER.
I
EN
DR
(ENABLE
DRIVERS)--
ILLEGAL
ADDRESS
~
ADDRESS
ACKNOWLEDGE
--
ATTENTION
-
CONTROL
INTERFACE
SEEK
BOARD
(CIB)
INCOMPLETE
--
SEEK
COMPLETE
CONTAINS
SECTOR
--
COUNTERS AND MISC,
CONTROL CIRCUITRY
REQUIRED TO TRANSFER
SIGNALS TO THE
CONTROLLER, READY
I/O
-
CONNECTOR
BOARD
(lOB)
(LINE DRIVERS)
SECTOR
ADDRESS
-.
1~32
SECTOR
---
INDEX
---
DATA
READ
DATA
INTERFACE
--
BOARD
(DIB)
DATA
CLOCK
~
FURNISHES READ
DATA
TO
THE CONTROLLER IN
WRITE PROTECT
EITHER NRZ
OR
PE
FORMAT,
--
SEPARATES READ
DATA
BITS FROM THE
DATA
CLOCK,
WRITE
CHECK
--
-
4---
READ/WRITE
HEADS
(4)
ILLEGAL
ADDRESS
ADDRESS
ACKNOWLEDGE
ATTENTION
SEEK
INCOMPLETE
SEEK
COMPLETE
READY
SECTOR
ADDRESS
1-"32
SECTOR
INDEX
READ
DATA
DATA
CLOCK
WRITE PROTECT
WRITE
CHECK
1----'
I
I
I
I
I
I
·1
I
.J
-I
I
I
I
J
P,
I
1
I
I
I
I
I
,
I
,
J
I
J
J
EXTERNAL
CONTROLLER
I
I
I
I
I
I
I
!
\
\
\
\
I
INITIATES,
MON
ITORS I
& TERMINATES
ALL
~C~g~oR~~,E
I
\
I
\
I
I
\
\
I
J
,
\
\
L
____
-.J
Figure 4-9. Block Diagram
-Super
Series (major signal lines) (sheet 2
of
2)
4-13
Page 73
(---,
I
\
\
I
I
I
I
I
I
I
I
I
I
I
I
EXTERNAL
\ CONTROLLER
INITIATES,
MONITORS,
\
TERMINATES
ALL
READ/
WRITE FUNC-
I
TIONS.
I
I
I
I
I
I
I
\
\
\
\
I
I
I
I
L
___
TEMPERATURE
SENSOR
SENSES
TEMPERATURE
OF
BASE
CASTING
AND COMPENSATES HEAD
POSITION
AS
REQUIRED.
IDCB)--------
TCV
TC
OF
COARSE SERVO
LOAD/UNLOAD
DIF.256/128H
D DAC
SERVO DET
FWDH
ODD
DETENT ODD H
DETENT
FWD
DIFF'lIL)
T
SPM
ON
BMONH
SOL
+
DOOR LOCK
SOLENOID
l
INHIBIT
DET
ISPEED
DATA
ADD 256/128
IFROM SLB)
DAC
TRAVEL
1+)
EVEN H
INHIBIT
DETECT)
X
PULSE
EN
IL)
1+)
EN
H
SERVO
AMPLIFIER
J
.
-
ADD 256/128
A~ ~R
SK
corvo
IFROM CIB)
BEGINNING
1
DATA
ELECTRONICS
BOARD
r5~
[rJ~~
I
I
I
WRT
SP
WRITE
WRITE
ERASE
..
I
I
I
ADD1_258
I
I
I
I
I
RESTORE
I
SEEK STROBE
I
I
I
UNIT
l
8<
DISK SELECT
I
HEAD SELECT
I
WRITE
I
WRITE
READ ENABLE
I
-.J
(4
ENr
SELECT
LINES)
GATE
DATA
-
,-
I
J DECODER l
L_
CONNECTOR (lOB)
(LINE
RECEIVERS)
-
I/O
I/O
-
I
-
ADD1~256
CLR STROBE
SEEK STROBE
EN
DR
J
~
J-
~
:;~~KM
-
..
:;~~KM-
-flo
HEAD SELECT
DISK SELECT
WRT CHECK X
WRITE GATE
WRITE
READ GATE
OUTPUT
DRIVERS
I
UNIT
SELECT
SWITCH
I
CARTRIDGE
INTERLOCK
&
RUN/LOAD
SWITCHING,
INDEX/SECTOR
TRANSDUCER
(REMOVABLE
DISK
INDEX/SECTOR
TRANSDUCER
IFIXED
DISK)
DATA
Li'i"HD
~
I
~
iJi"Hi)
RUNH
INDEX/SECTOR
INDEX/SECTOR
-
SERVO
LOGIC
BOARD
(SLB)
CONTAINS CYLINDER
ADDRESS
REGISTER AND
GENERATES A SIGNAL
PROPORTIONAL TO
NUM8ER
OF
TRACKS THE
POSITIONER
HEAD
MOVE. ALSO CONTAINS
SOME
TEMPERATURE
COMPENSATING CIRCUITRY.
DISK
CONTROL
BOARD (DCB)
CONTROLS DISK
OPERATION
MAINTAINS DISK
SPEED
CONSTANT.
SEPARATES INDEX
AND
SECTOR
PULSES.
CONTROLS
HEAD LOAD/
UNLOADING
MODIFIED
FREQUENCY
MODULATION
BOARD (MFM)
(4400 BPI)
CHANGES NRZI
THE CONTROLLER
DATA
DATA
-
THE
HAS
AND
TO
--
TO
FROM
MFM
RETRACT
~
Figure
4-10.
Block
Diagram-Super
Series
(major
4-14
signal
lines) 4400
BPI
Only
(sheet
1 of
2)
Page 74
----
--
-
-.
--
--
-
-_._---
-'.
~~:~TRONICS
•
_____
-.-:(.;...4
;;.;LI.;...NE;,..;;S;.../H;...EA.;...D:.;.)
____
---.
038612
BOARD
POSITION
BEGINNING
OF
TRAVEL
PULSE
TRANSDUCER
AGC
t
WRITE
DETENT PULSE
GENERATES POSITION
~
INFORMATION
AS WELL
LIGHT
SOURCE
AS
HOME & DETENT
FOR
OPTICAL
SIGNALS.
READ
LAMP VOLTAGE (10V)
DETENT ASSY.
SERVO
TRANSFERS
LIGHT
AMPLIFIER
TO PHOTOCE LLS TO
DC
LOSS
BOARD (SVA)
GENERATE DETENT
SIGNALS.
POSITIONER
THE
MAIN
FUNCTION
OF
THE
(MOTOR
DRIVE)
MOTOR
SERVO AMPLIFIER
IS
TO DRIVE
POSITIONS
----
THE SERVO MOTOR.
IT
ALSO
SUMS
THE
VELTACH
READIWRITE
SIGNAL
WITH EITHER THE
HEADS
..
INPUT FROM TH E COARSE 0 R
FINE SERVO
LOOP
FOR HEAD
POSITIONING.
-
VELOCITY
RDY INH
TRANSDUCER
(VELOCITY
DATA)
SENSES
VELOCITY
OF
POSITIONER MOTOR
DETENT
EN
AND REPORTS INFOR·
MATI
ON
TO SERVO
TRK
OFF SET
AMPLIFIER.
I
DT
EN
(DETENT ENABLE HIGH)
DLYSK
.,
EN
DR
ILL
ADD
(ENABLE DRIVERS)
SK
(SEEK)
.,.
..
ILLEGAL
ADDRESS
CLR STROBE
.,..
SEEK STROBE
ADDRESS
.,..
-
ACKNOWLEDGE
-
ATTENTION
RETURN ZERO
CONTROL
?SEUDO SECTOR 2000
INTERFACE
SEEK
.,
BOARD (CIB)
INCOMPLETE
RDYl
DC
LOSS
.,...
F SECTOR
SEEK
.,.
COMPLETE
F INDEX
.,
CONTAINS SECTOR
.,.
R SECTOR
COUNTERS
AND
MISC.
R INDEX
CONTROL CIRCUITRY
.,
REQUIRED TO TRANS·
FER SIGNALS TO THE
""NO" omv,
~
CONTROLLER. READY
I/O
LIMITER
MODULE
CONNECTOR
AND
POWER
SPINDLE
BOARD (lOB)
SWITCH MOTOR
(LINE DRIVERS)
PROVIDES SPINDLE
MOTOR CURRENT
SECTOR ADDRESS
TO •
1~32
RIW
4--.,
~~
HEADS t SPINDLE
TO
INDEX/
SECTOR
t---
DISKS
-+-
....
SECTOR
TRANSDUCERS
BRUSH
-.J
BRUSHES
I
MOTOR
INDEX
WRT CHK X
I 1
DISK SELECT
t t I
-~
DATA
READ
DATA
1
MODIFIED
READ
DATA
ELECTRONICS
FREQUENCY
READ
DATA
2
MODULATION
BOARD (DEB)
BOARD (MFM)
CLOCK
(4400 BPI)
PROCESSES
I/O DAT A FROM/TO
THE CONTROLLER. IN SEPARATE
CHANGES MFM
DATA
TO
READIWRITE CHANNELS.
NRZI FOR THE CONTROLLER
PROVIDES WRITE PROTECT LOGIC
TO ENSURE
DATA
IS NOT ERASED
INADVERTENTL
Y.
ALSO
REGULATES"
13V.
-
..-
-
I
WRITE
_____
READIWRITE HEADS
~READ
(4
LINES)
......
---
-
READ/WRITE
HEADS
(4)
ILLEGAL
ADDRESS
ADDRESS
ACKNOWLEDGE
ATTENTION
SEEK
INCOMPLETE
SEEK
COMPLETE
READY
SECTOR ADDRESS
1
....
32
SECTOR
INDEX
READ
DATA
CLOCK
,----,
I
J
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
J
-I
I
I
I
J
J
I
I
EXTERNAL
CONTROLLER
I
I
!
I
I
I
I
\
\
\
\
\
I
INITIATES,
MONITORS I
& TERMINATES
ALL
~~~g~~~~~
I
\
\
I
I
I
\
\
I
/
I
\
\
L
____
~
Figure
4-10.
Block
Diagram -Super
Series
(major
signal lines) 4400
BPI
Only
(sheet
2 of
2)
4-15
Page 75
The
Controller
may
now
initiate a Seek (SK) Command and load the
cylinder
address
to
which
the carriage
is
to
be
moved. This
information
is
routed
to
the Servo Logic Board where the
cylinder
(track) address
is
strobed
into
the New Address Register. This binary number then
is
compared
to
the value stored in the Current Address Register. This register consists
of
up/down
binary count-
ers
containing the binary value representing the present positioner carriage location. These
two
values
are
compared, and a difference value
is
obtained which represents the difference between
these
two
binary numbers. This difference value
is
applied
to
a D-A converter
to
provide
an
analog
drive signal
which
is
sent
to
the Servo
Amplifier
Board. A simplified
block
diagram
of
the head
positioning system
is
shown in Figure 4-11.
CONTROLLER:
NEW
ADDRESS
t---~
____
--1
CURRENT
ADDRESS
SUBTRACTOR------~
SHAPING
CIRCUIT
Figure 4-11. Functional Block Diagram - Head Positioning System
4-16
1125-001
\
I
POSITION
TRANSDUCER
Page 76
The circuits on the Servo
Amplifier
Board route the analog signal through the board
to
the linear
DC
positioning
motor,
and the carriage
is
moved toward the new address at a
speed
proportionate
to
the number
of
tracks
to
be
crossed. The position transducer detects the crossing
of
each
track
as
described in the discussion
of
mechanical operation
of
the head positioning system. The Current
Address Counter
is
updated
with
the counter being incremented
or
decremented
as
required. Once
the value in the Current Address Register
is
equal
to
that
in the New Address Register, the Detent
Enable
(DET
EN) signal
is
sent
to
the Control Interface Board (CIB). A status signal, SEEK CaMP,
is
generated on this board and transmitted
to"the
Controller
signifing
that
the addressed track
has
been reached and
that
the Read/Write heads
are
settled over the desired track and locked
or
de-
tented in place.
When the
SEE
K CaMP signal
is
received by the Controller, a
Read
or
VVrite
operation may
be
initiated. A functional block diagram showing the logic circuits associated
with
Read
and \Nrite
operations
is
shown in Figure 4-12.
Head
selection determines which surface, upper
or
lower,
will
be
written
on
or
read
from. A decoding
matrix
on the Data Electronics Board (DEB)
will
deter-
mine whether the fixed
or
cartridge disk
will
be
selected. Write data
are
routed
from
the
Controller
through the
DIB
or
MFM
to
the DEB, and
Read
data
is
routed
from
the DEB
to
the DIB
or
MFM
to
the Controller.
Circuitry
on the Servo
Amplifier
Board (SVA) electronically keeps the carriage
detented
so
the
heads
are
positioned
directly
over the addressed track during either a
Read
or
Write operation.
1
}
1126-0 1
o
•
ERASE
.....
OTHER
HEADS
DRIVER
-
~I(
~
ERASE
GATE
w Z
I
en
-
«
Cl
II:
~
DISKIHEAD
WRITE
GATE
w
3:
DECODER
-
WRITE
DRIVER
R/~
..
DRIVER
•
WRITE
DATA
4~
.
~
~~
~~
~~
HEAD
~~
HEAD
DISK
SELECT
SELECT
~~
~~
DATA
ClK
r--
r--
DATA
SEPARATOR
~
•
~
-
...
..
......
PRE- V
LOW-PASS
d
-
BI-DIRECTIONAL
_
AMPLIFIER
-
FILTER
...
dt
--
ONE-SHOT
-~
-
READ
GATE
Figure 4-12. Functional Block Diagram - ReadlWrite
Circuit
4-17
Page 77
4.5
LOGIC
BOARD
CI
RCUIT
ANALYSIS
4.5.1
I/O
CONNECTOR
BOARD
(lOB)
4.5.1.1
Board Functions. The main functions performed by the logic circuits on this board
include:
A. Line Receivers
B.
Line Drivers
C.
Daisy Chaining
4.5.1.2 Line Receivers. The command and data signal lines
from
the
I/O
cable enter the Disk
Drive through connector J22 which
is
wired in parallel, pin-by-pin,
with
daisy-chain connector J23.
Each
input
is
connected
to
one
input
terminal
of
its associated line receiver. These lines
are
also
connected
to
a terminating bias by a resistive network. The second
input
to
each
line receiver
is
a
common enabling signal,
EN
RECV. A block diagram
of
this
I/O
Connector Board, showing the
line receivers and drivers,
is
shown in Figure 4-13.
The
input
signals
from
the Controller
are
low-true signals; i.e., a logical
"1"
is
defined
as
a level
between 0 and 0.5 V. The inverting line receivers furnish high-true signals (logical
"1"
is
repre-
sented
by
a level
of
approximately +4 VDC
to
the drive system). The receiver
outputs
are
routed
to
the Electronics I nterconnect Board
(E I B)
through connector J20
and
the flexible intercon-
necting ribbon cable assembly.
4.5.1.3 Line Drivers. The status and data signals generated in the Disk Drive
are
routed
to
the
lOB
from
J20
through the ribbon cable and connector J21.
Each
signal
is
routed
to
one
input
of
the corresponding line driver. The second
input
to
each
line driver
is
a common enabling signal,
ENDR. The low-true outputs from the line drivers
are
transmitted
to
the Controller through
I/O
connector J22 and the interconnecting cable.
4.5.1.4 Driver Enable Circuits. A control
circuit
on the lOB generates the enable signals
for
the line receivers
and
line drivers
as a function
of
the UN
IT
SE
LECT. The logical address signal
for
selection
of
one
of
the
four
daisy-chained Disk Drives
is
received
from
the
Controller
via the
I/O
cable and connector J22. This signal
is
inverted and applied
to a NAN
D gate. The second
input
to
this gate
is
furnished
by
the SEL1/SEL2 decoder. The decoder
is
supplied
by
the four-position
UN
IT
SE
LECT switch which
is
located "on the control panel
of
the particular Disk Drive. The
inputs on lines SEL 1 and SEL2
are
encoded
by
the
UNIT
SELECT switch mechanism.
4-18
Page 78
CONTROL
INTERFACE
BOARD
UNIT
{
SELECT
SWITCH
CONTROL
INTERFACE
BOARD
CONTROLLER
J21
SEL
1
J23
J22
1127B-001
SEEK
INCOMP
SEEK
INCOMP
EN DR -4...-_-
....
RDY
RDY
I
LL
ADD
ILL
ADD
ADD
ACK
ADD
ACK
EN
DR--
___
,
o
ATTENTION
TO
CONTROLLER
1
ATTENTION
2
ATTENTION
3
ATTENTION
SEEK
COMP
EN
DR
--I--+~~+--I
~
UNIT
SELECT
NO.
0
UNIT
SELECT
NO.1
UNIT
SELECT
NO.2
Yr--4
......
EN
RECV
UNIT
SELECT
NO.3
CL
RESTORE
SEEK
STROBE
}
FROM
CONTROLLER
DAISY
CHAIN
CONNECTOR
Figure 4-13. Block Diagram -
I/O
Board (Sheet 1 of 2)
4-19
Page 79
CONTROL
INTERFACE
BOARD
DATA
INTERFACE
BOARD
DATA
ELECTRONICS
BOARD
112SB-001
J21
EN
DR
SH.1
J23
J22
STRISAC 32
SAC
16/F STR
SAC
S/F
lOX
lOX
CONTROLLER
SAC 4
SAC 2
SAC 1
DATA
CLK/WRT
CHK
X
WRITE
DATA
RD
EN
GATE
READ
DATA
HEAD
SEL
CONTROLLER
DISK
SEL
WRITE
PROT
ERASE
GATE
WRITE
GATE
Figure 4-13. Block Diagram - I/O Board (Sheet 2
of
2)
4-20
Page 80
When both inputs
to
anyone
of
the
gates
are
high, indicating matching selection (remote and local
of
the
unit
address), the
output
of
that
particular gate
will
be
low:
therefore, the
EN
REC signal
is
low. This low-level signal enables all line receivers. The
EN
REC signal
is
inverted
to
a high level
and the resultant EN
DR
signal
is
used
to
enable all line drivers.
The decoder
outputs
are
further
used
to
generate the
ATTENTION
status signal. Depending on
wh ich gate
is
enabled by the high-level
output
of
the decoder, a
low
level wi
II
be
placed on the
respective
ATTENTION
line when the internal
ATTENTION
signal
is
received.
4.5.1.5
Daisy Chaining. The daisy chaining provision
is
implemented
with
the
two
parallel-
wired connectors J22
and
J23. The
I/O
connector J22
(a
male connector) mates
with
the interface
I/O
cable. The entire communications
link
between the .DiskDrive and the Controller
is
established
via this cable. The parallel (pin
by
corresponding pin) daisy chain connector, J23
(a
female recep-
tacle), mates
with
one end
of
a daisy-chain cable whose'
other
end mates
with
I/O
connector
J22
of
the second Disk Drive, etc. Up
to
four
drives
can
be
interconnected
with
the
Controller
in this
manner. The daisy chain cable
will
be
terminated in the end
unit
by inserting a
terminator
plug
into
J23.
Circuitry
is
provided
to
disable
Output
Drivers when one
of
the Disk Drives in a daisy
chain
is
powered up
or
down. Spurious 5 V. fluctuations
are
prevented
from
interfering
with
other
drives in the chain by th
is
means.
4.5.2 ELECTRONICS
INTERCONNECT
BOARD
(EIB)
This
is
basically a
mother
board
into
which the other
circuit
boards
are
inserted. The intercon-
necting diagram
for
th
is
circuit
board
is
in the schematic drawings
of
Volume
2.
Since this
circuit
board
is
used
only
to
provide interconnecting signal paths, no
further
information
is
included.
4.5.3
DISK
CONTROL
BOARD
(DCB)
4.5.3.1
Board Functions. The principle functions performed by the logic circuits on this board
include:
A. Spindle start-up and control
B.
Separation
of
Index and Sector pulses
C.
Generation
of
Disk Drive
control
signals
4-21
Page 81
4.5.3.2 Spindle Start-Up and
Control.
The spindle
motor
speed
detection and
control
circuitry
is
used
to:
(1) provide a
clock
signal
of
2000
pulses
for
each
revolution
of
the disk; (2)
monitor
the
speed
of
the spindle
motor,
and (3) generate the Spindle
Motor
On
(SPN
MOTOR
ON) signal. The
block
diagram
for
this
circuitry
is
shown in Figure 4-14.
CRYSTAL
OSCILLATOR
8 MHz
I
DIVIDER
1
DIVIDER
2
I
-
4t--
4t--
"
FIDX
(RESET)
COUNTER 1
I--
CNT 1980
COUNT
CNT 2020
COUNTER
2
I--
DECODE
LOGIC
CNT 2000
CNT 2048
COUNTER
3
-
0888
SPEED
SP
DETEC
DET
TO DEB
LOGIC
-
SPEED
SP
MOTOR
ON
CONTROL
-
TO MOTOR
to-
LOGIC
RTZ
RETRACT
LOGIC
-
4~
TO SLB
"
FIDX
Figure 4-14. Spindle
Motor
Speed Detection and
Control
Functional Block Diagram
A
simplified
logic diagram and a
timing
diagram
are
provided in Figures 4-15 and 4-16 respectively.
Two
of
the inputs
to
AN D gate
"A"
(see
Figure 4-15)
are
+5V
and the
output
of
the
DC
LOSS
TI
ME R one-shot. During normal operation, these inputs
will
be
high and
the
Spindle
Motor
Start
(SPM
START)
one-shot
will
be
triggered when the
RUN/LOAD
switch
is
set
to
RUN position.
-
-
DC
LOSS
(L)
AC LOSS
TIMER
I---""TO
SVA
O/S
DC
LOSS
TIMER
O/S
TO
RETRACT
F F
+5V
CELL
3
-
-
SPM
START
O/S
FF
SPM
ON FF
(SPM
ON
SW)
SPN
SPEED
DET
OS
Figure 4-15. Spindle
Motor
Control
Simplified
Logic Diagram
4-22
0874/2
SPN
MOTOR
ON
(L)
Page 82
NORMAL
OPERATION
OF
MOTOR PULSING
0961
COUNT 1980
FF
---'
SPlrLE
SPEED DECREASES
DRASTICr-A_L_L_Y
__
L
COUNT 2000
FF
-----------------------
....
L
COUNT 2020
FF
__________________________________________________
~r__l
__________
~~
COUNT 2048
FF
FIDX
_____
-'n
....
______
---In
....
______
.....In~
______
rL
SP
DETEC
FF
_
_____
--'k-DECREASE
SPEED
SPM
ON
FF
-
J..-=INCREASE
SPEED
RDY1----
....
t+:=RDY
1 GOES FALSE
RTZ
Figure 4-16.
Motor
Speed
Control Timing Diagram
4-23
Page 83
The
output
of
the
SPM
START
one-shot
will
be
high
for
3.36 seconds and
will
be
one
input
to
NAND
gate
S.
The
other
two
inputs
will
be
high due
to
logic reset when
power
is
turned on. The
output
of
NAND
gate
S,
SPN
MOTOR
ON
(L),
will
allow
the spindle drive
motor
to
be
turned on.
Once the spindle begins
to
turn,
CE
LL
signals
will
be
generated
by
LED circuits on the COMMU-
T
ATO
R board.
It
can
be
seen
(see
Figure 4-15)
that
the
CE
LL
3 signal
will
trigger the Spindle
Speed Detect
(SPN
SPEED DET) one-shot.
CE
LL
signals occur once every revolution
of
the spindle;
therefore,
CE
L L 3
will
retrigger the
SPN
SPE
E 0 OET one-shot
so
often
it
will
never have a chance
to
time
out. This
will
provide a constant high through OR gate C
to
NAND
gate S
so
when the
SPM
START
one-shot times
out,
the
SPN
MOTOR
ON
(L) signal
will
be
held constant.
The spindle
motor
will
be
turned on
by
SPN
MOTOR
ON (L)
until
it
exceeds the designated rpm
(1500
or
2400). Then through the
timing
relationship between the Counter decode
outputs
(see
Figure4-14)
and the occurrence
of
Fixed Index
(FIDX)
pulses, the Spindle
Motor
On
(SPM
ON)
f-f
will
be
toggled periodically, and its Q
output
(input
to
NAND
gate
B,
see
Figure 4-15)
will
either
allow
or
inhibit
spindle
motor
drive current. This pulsing
of
the spindle
motor
is
the method
employed
to
maintain spindle (disk)
speed
at
a constant rpm
±.
1 percent.
4.5.3.3 I ndex and Sector Pulse Separation. \Nhen the Sector pulse
that
preceeds the Index
pulse arrives,
it
will,
after
shaping, fire the
lOX/OAT
A Timer.
See
Figures 4-17 and 4-18. The
R
lOX
Pulse Widener
will
be
fired
by
the
trailing
edge
of
the
lOX/DATA
Timer
when
it
times
out.
The
output
of
the pulse widener enables one
input
to
two
AN
0 gates
(1
and 2). Since the R
lOX
Separator
is
not
firing
yet, its bubble
output
is
high and enables AN 0 gate 1
so
its
output
becomes
the Removable Sector (RSTR) pulse. The
next
pulse
to
arrive at the
input
to
the
timer
(pulse
widener, etc.),
will
be
the Removable Index
(RIOX)
pulse. This pulse
will
arrive at
AND
gate 2
while
the
RIOX
Separator
output
to
AND
gate 2
is
still high (because
it
was
fired
by
the negative
transition
of
the widener
timing
out
and
has
not
yet
timed
out).
The
output
of
AN
0 gate 2
now
becomes
RIDX;
therefore,
RIOX
and STR
are
now
on separate lines. The operation
of
Fixed
IDX/STR
is
basically the
same
except
for
the
lOX/DATA
timer
which
is
only
adjusted
while
using
a
CE
Cartridge disk; therefore,
it
is
unnecessary
for
the fixed disk
circuitry.
4-24
Page 84
SECTOR IN
(REM)
DIFFERENTIATOR
AMPLIFIER
SCHMIDT
TRIGGER
/OX/DATA
TIMER
RIDX
P.W.
RIDX
SEPARATOR
0874
t-----I~
RI OX
t--
.....
--I~RSTR
Figure 4-17. Removable Disk I ndex/Sector Separation
i1.6MS
I
610 jJS
I 1
MS
.~
.....
..
1.6MS
1.6MS
'NOTE:
1500
RPM
UNIT
WITH 24 SECTOR RING
TIMING
IS
SAME FOR
SF
AND
ST
BUT OUTPUT
OF
TRANSDUCER
WILL
BE
DIFFERENT.
0875
,-------FM
XDUCER
U
....
------SCHMIDT
TRIGGER
Fi!~ure
4-18. Removable I
DX/STR
Pulse
Timing
Diagram
4-25
Page 85
4.5.3.4
Generation
of
Disk Drive
Control
Signals
4.5.3.4.1
RTZ.
A return-to-zero carriage
return
signal
is
generated
during
the power-on sequence
to
ensure the carriage
is
retracted before the loading
door
can
be
opened.
VlJith
the
RUN/LOAD
switch in
LOAD
position,
the RUN
(L)
input
to
the
I)CB
is
high.
This
direct
resets
the
RETRACT
f-f
sets the
CNT
2048
f-f
and causes
the
RDY
D L Y
"A"
f-f
to
be reset.
See
Figure 4-19.
The
Q
output
of
this
f-f
generates
the
RTZ
high signal
to
the
SLB.
CNT
2000
FF
FIDX
RETRACT
AC OR
DC
LOSS
NOT
RDY
+5V
DC LOSS
(-)
RUN
(-)
D o
C
RETRACT
o
D
o
SPM
C ON
FF
SPM
ON
SW
010----
......
D
TO
NAND
GATE
"B"
C
BRUSH
MOTOR
ON
CNT
1980
FF---I...-
........
CNT
2020
FF-
__
_
0
D
RDY
DLY
"A"
FF
FF
-
0
0
CELL
3
D
ot---
.......
CELL
1
SPINDLE
CCW
FF
RETURN
ZERO
Figure 4-19. Disk
Control
Signals -
Simplified
Logic Diagram
4-26
0
LD
HD
(U
l--_"'RDY
1
~-_~
RTZ
Page 86
When the
RUN/LOAD
switch
is
in RUN position, the spindle starts, and the
CE
LL
1 and 3 signals
(then generated)
cause
the spindle
CCW
f-f
to
set. This results in the
RDY
DLY
"A"
f-f
getting
set when the
first F IDX
pulse after the CNT 2048
f-f
set arrives. This
causes
RTZ
to
go
low.
RTZ
will
remain
low
unless one
of
the
following
occurs:
A. The RETURN ZERO command
from
the CIB
is
received
B.
The
RETRACT
signal
from
the SLB
is
received
C.
AC
or
DC
Loss
occurs (emergency retract)
D.
Excessive spindle
speed
loss
(count
of
2048)
E.
RUN/LOAD
switch
is
placed in
LOAD
position
As a result
of
any
of
these conditions, signal RTZ
will
go
high and the carriage
will
retract.
4.5.3.4.2 LD H
D.
The Load
Head
pulse
is
sent
to
the S
LB
where
it
starts the I nitial
Seek
oper-
ation wh ich includes loading the
heads.
When the disc
is
up
to
speed
(see
AN
D gate
input
to
direct
reset
of
RDY
D L Y
"A"
f-f
in! Figure4-18), the
RDY
D L Y
"A"
f-f
will
be
set
by
FI
DX
and spindle
CCW.
The
following
FIDX
pulse
will
set
RDY
DLY
"B"
f-f. The
next
FIDX
pulse
will
gate LD HD
to
the SLB.
At
the
same
time,
RDY 1 will
be
sent
to
the CIB
for
processing and eventual gener-
ation
of
READY
to
the
Controller
after the
Initial
Seek operation
is
finished.
4.5.3.4.3
SP
DETEC. The
Speed
Detect signal, when low, allows Write operations. When
it
is
high,
it
inhibits
Write operations on the DEB.
SP
DETEC
will
be
high
if
the counter decode at
FIDX
time
is
less
than 1980
or
more than 2020.
If
the
FIDX
pulse arrives before the
count
of
1980,
the spindle
is
turning
too
fast; and
if
the F I
DX
pulse arrives after the
count
of
2020, spindle
speed
is
too
slow. Either
condition
would
cause
data
to
be
written
in
an
unacceptable Sector
format
(see
Figures4-19 and 4-16).
4.5.3.4.4
AC/DC
Loss
Recovery. The
loss
of
either AC
or
DC
will
result in the
RETRACT
flip-flop
being reset and triggering
of
the
DC
LOSS
TI
MER one-shot
(see
Figures 4-15 and 4-19).
If
the
loss
is
short duration,
as
explained previously in the description
of
the Positioning assembly,
the drive wit! automatically restart once the
DC
LOSS
TI
ME
R one-shot
has
timed
out,
and the
setting
of
the
POWE
Rand R UN/LOAD
switches remains unchanged.
4-27
Page 87
Some
other
secondary
control
signals generated on the DCB are:
A. Load
indicator
driver (light)
B.
Solenoid driver (locks
or
unlocks cartridge door)
C.
Power reset (initial
circuit
Reset pulse during power up)
D.
Brush
Motor
On (self explanatory)
4.5.4
SERVO LOGIC
BOARD
(SLB)
4.5.4.1
Circuit
Functions. The principal functions performed
by
the logic circuits on this
board
include:
A. Store new
cylinder
address
B.
Store current positioner address
C.
Compare and compute difference between
NAR
and CAR
D.
Decode illegal
addresses
E.
Generate positioner
control
signals
F.
Provide temperature compensation (200 TPI
units
only)
4.5.4.2
New Address Register
(NAR).
The SLB contains the New Address Register
into
which
the desired
cylinder
address
is
loaded at the start
of
any Seek operation. Prior
to
an
initial
Seek
or
Restore operation, this register
will
be
reset
by
the Clear Counter
(CL
CNTR)
signal. During a
programmed Seek, the new
cylinder
address
from
the
Controller
will
be
routed
to
th8 SLB on
input
lines
ADD
1 through
ADD
256. These inputs
are
applied
to
the 100 and
200
TPI
multiplexer
whose
outputs
are
then strobed
into
the
NAR
by
the Seek Strobe (SK). Therefore, during contin-
uous
or
alternate Seek operations, the
NAR
need
not
be
reset
prior
to
each
Seek. A
block
diagram
of
the SLB
is
shown in Figure 4-20.
4.5.4.3 Current Address Register (CAR). The CAR
is
made up
of
three
four-bit
up/down
counters and associated
control
gating
circuitry.
The
count
down and
count
up
NAN D gates
are
enabled by the Q and Q
outputs
of
the FWD
flip-flop
respectively. ,They
are
activated by the
detent
pulses
(DT
P)
from
the
SVA.
The
output
of
the CAR
will
always reflect the current address
of
the
cylinder
over which the Read/Write heads
are
presently- positioned. These counters
are
reset in the
same
manner (CL
CNTR)
as
the
NAR.
4-28
Page 88
ZERO
ILL
ADD
DET
ODD
SK
DLY
LOAD/UNLOAD
CIRCUITRY
9
(LINES)
FROM
CONTROLLER
"NEW
ADDRESS"
8
LINES
ILLEGAL
ADD
DECODER
0963-001
ILL
ADD
SK
>-------~
....
------__1
TCV
DL Y DT
...
-----------.
CLCNTR
(L)~---
__
-'
CNT
PLS EN
>---------'----i
DT
P >-
______
---J
UNLOAD(Ll
>-----,
DL Y SKILl
C
FWD
F-F
LOAD
>-
___
---J
r---------------------------------~TDAC
9
LINES
CAR
DT
EN
>----i
r------,
256/128
5
LINES
D/A
CONVERTEH
SUB
4
SUBTRACTORI1~-t_---~~~1----~
7
LINES
~
ZERO
DECODER
D
DAC
ZERO
~-~----_4------------------
..
0DD(L)
~~---------------------------------------_4.FWD(L)
Figure
4-20.
Block
Diagram
of
Servo
Logic
Board
(SLB)
4-29
Page 89
4.5.4.4
Subtractor
and Digital-to-Analog Converter. The inputs
to
the
subtractor
are the
complimentary
applied
tractor
to
LSB
amount
to
using the 1's
a digital-to-analog converter whose
is
decoded
of
This signal
4.5.4.5
to
a decoder
for
the disc,
outputs
full
adders which are configured through the
to
drive needed
is
called DI F F
Illegal Address Decoder
circuit.
an I LL
of
the
NAR
compliment
generate the ZE
to
advance the carriage the final distance
1.
See
Figure 4-21.
If
the value
ADD
status signal
of
and
the
to
obtain the difference figure. This difference
output
RO
(I
the
is
LL
signal D
signal
AD).
binary
generated. The address
current
but
is
The Q
number
address
use
DAC
also routed
from
of
exclusive OR gates
is
routed
to
to
outputs
is
of
greater than the valid
is
ignored
to
the
the selected
the
carriage remains in its present position. Legal addresses are indicated
625
or
627
for
200
4.5.4.6
transducer
two
developed on
TPI Disk Drives and octal
Beginning
of
Travel Pulse. The Beginning
tracks before the carriage reaches track
the
SVA
board and
is
routed
312
or
313
for
100 TPI models.
of
Travel pulse
000
position. This negative-going pulse
to
the SLB. There, the positive
the
CAR.
These inputs
as a binary
count
the
SVA.
The
SVA
to
generate
track
NAR
flip-flops
number
by
the Disk Drive and the
for
values
less
See
is
developed
by
transition
sub-
is
applied
Subtractor
the
small
for
detenting.
are
applied
of
tracks
than octal
Figure 4-22.
the
position
is
used
are
is
to
clear
the
positive
LOAD
LOAD/UN
f-f
and
to
LOAD
set the D L Y
signal
tinued. The second detect pulse
setting the
LOAD/UN
the
DETENT
LOAD
f-f. The
output
signal, and the
4.5.4.7 Detent Operation.
which
ation
pulse
slows
recording track. Because
is
cursion
eventually
the
first
odd
of
the
first
has
a negative slope; e.g.,
down
rapidly
driven backward
of
the
Detent
be
generated.
Detent
odd
Detent
to
approximately
of
toward
signal. When
pulse
pulse and start
the moving-mass inertia, some overshoot
track
to
after
Track
after
it
is
000
the
/BOT
the
the
of
positioner
000
positive and
zero
f-f. The Q
SVA
board and ensures
BOT
pulse
the
DETENT
is
detented (locked)
is
defined
BOT
is
detected. Detent takes place between the term,in-
of
the
dropping
forward
(the zero crossing
carriage
is
locked over track 000, SEEK COMP signals
causes
as
the
even
speed
output
f-f
as
of
of
the D L Y
that
signal
DETENT
clears the
at
track
position
Detent
toward
it
of
pulse.
zero. Therefore, the positioner
approaches the addressed concentric
will
the
detent
/BOT
f-f
forward
DL
motion
ODD
Y/BOT
to
f-f
thus removing
000.
the carriage (and heads) at
At
this
point,
occur,
signal)
but
the
by
the negative
maintains the
will
be
con-
go
low
thus
the
Detent
positioner
ex-
will
4-30
Page 90
OM
CURRENT
FR
DDRESS REGISTER
A
Q
FWD
F/F
Q
I
-
U
-
NAR 256
CAR 256
CAR 128
-
NAR 128
CAR 64
-
NAR 64
CAR 32
-
NAR 32
CAR 16
NAR16
CAR 8
-
NAR 8
CAR4
-
NAR4
CAR 2
-
NAR 2
CAR 1
-
NAR 1
-
SUB-3
T
SUB-2
I
SUB-l
I
~
D-
~
\
.H
\
4~
\
o-}
\
4H
\
.
.--l
\
4~
~~
-,
"
.H,
Z
1129-002
DIFF
VALUE
TO
D/A
CONVERTER
DIFF
1
TOSVA
Figure 4-21. Subtractor Circuit - 200 TPI
4-31
Page 91
NAR256------------------------------------------------~
NAR128--------------------------------------------------~
NAR
64
-------------------------\
1130-001
NAR32
NAR
NAR
NAR
NAR
--------------------------~
8
16
--~
......
__t._~
4
2
a. I LL
ADD
Decoder - 200 TPI
NAR128-----------------------------------------------
NAR64
NAR32
-----------------------------------------------~
----------------------------------------
1131-001
NAR16
NAR
NAR
NAR
---------------------------------
8
4
2
NAR1
Figure 4-22. Illegal Address Gating Circuits
b. I
LL
ADD
Decoder - 100 TPI
4-32
Page 92
4.5.4.8
Detent
Pulses.
As the carriage moves the Read/Write
heads
radially across the con-
centric recording tracks, the optical position transducer detents the track crossing
as
described in
the mechanical description
of
the
head
positioning servo system. The position transducer transmits
a
series
of
modified
sinewave signals
to
the SV A board
(see
Figure 4-11) through the Detent
Ampli-
fier
board. There, the pulses
are
shaped and amplified; then, depending on the
phase
of
the modi-
fied sinewave, the DET ODD
or
DET EVEN pulses
are
produced. These pulses
are
gated
with
the
selected
output
of
the
FWD
flip-flop
to
produce the signal required
to
increment
or
decrement the
Current Address Register.
4.5.4.9 Zero Difference. The updated
output
from
the CAR
is
constantly compared
to
the
binary
cylinder
address stored in the
NAR
during a
Seek
operation
by
the SUBTRACTOR. Vlhen
the
SUBTRACTO
R detects
that
the current value in the CAR equals
that
stored in the
NAR,
a
ZE
RO
signal
is
generated. This signal enables the
set
input
of
the Detent f-f, and this
f-f
wi"
be
clock-set when the Delay Detent one-shot times out.
4.5.4.10 Temperature Compensation Voltage (TCV). The
TCV
signal
(used
on the 200 TPI
Disk Drive
only)
provides temperature compensation consisting
of
an
analog signal proportional
to
the ambient temperature
within
the Disk Drive. This
is
accomplished
by
processing the
output
of
a
thermistor
located on the
base
of
the
chassis.
The analog signal
is
set
at zero tolerance
at
the
mid-point
of
the operating
range.
A procedure
to
be
used
in
monitoring
operation
of
the tem-
perature compensation
circuit
is
described in Section
5.
4.5.5 SERVO
AMPLIFIER
BOARD
(SVA)
4.5.5.1 Board Functions. The main functions performed
by
the logic circuits on this
circuit
board include:
A. Provide drive current
to
positioner
motor
B.
Generate BOT and Detent pulses
C.
Energize Servo
motor
relay
A block diagram
of
the
SVA
circuit
board, showing the principal signal paths and functional blocks,
is
shown in Figure 4-23.
4-33
Page 93
1132-001
DIFF
2MSB
---
VELOCITY
SUMMING
NOTCH
POWER
FORWARD
1
GEN
AMPLIFIER
~
FILTER
-
AMPLIFIER
DRIVER
DDAC
SERVO
OUTPUT
DETENT
..
-
SIGNAL
ELECTRONIC
TACH
-H
NETWORK
REVERSE
-
OFFSET
DRIVER
REV
OFFSET
OFFSET
AMPI
~-O
TEMP
FWD
COMP
TCDAC
I
POS
CHAN
1
~
DETENT
POS
CHAN
2
CIRCUITRY
DETENT
TO
~
ELECTRONIC
TACH
NETWORK
CURRENT
FAULT
CURRENT
DUAL
MTR
FAULT
THRESHOLD
-
DETECTOR
DETECTOR
RTN
-
I
»
D.C. LOSS
(-)
SERVO
DETENT
MTR
I
SIGNAL
RELAY
..
-
DRIVER
-
DETECTOR
RELAY
AGC
LED
-
AMPLIFIER
DRIVER
....
DETENT
ODD
(-)
PULSE SHAPER
-
-
POSITION
CHANNEL
AMPLIFIER
AMPLIFIER
DETENT
EVEN
(-)
__
(INVERTING)
H
..-
(INVERTING)
~
PULSE SHAPER
-
Figure 4-23. Block Diagram
of
Servo
Amplifier
Board (SVA)
4-34
Page 94
4.5.5.2
D
DAC
Input.
The
SVA
receives the
output
of
the Digital-To-Analog Converter
from
the SLB. In the
Velocity
Ramp Generator
it
will
appear
as
shown in Figure 4-24. The
illustration
represents the
output
of
the
D-to-A
Converter
as
it
converts the difference
count
from
the sub-
tractor.
Note
that
when the difference
count
is
maximum,
the D
DAC
signal
is
maximum
ampli-
tude;
and
as
the difference
count
reduces (value in the CAR approaches the value stored in the
NAR),
it
will
correspondingly decrease in amplitude. The
output
of
the
Velocity
Ramp Generator
and its inverted signal are applied simultaneously
to
two
FET's.
During a
LOAD
or
UN
LOAD
operation, the corresponding
FET
(LOAD
or
UN
LOAD)
will
be
activated
by
the state
of
the
LOAD/UN
LOAD
signal and either the high Q
or
low Q output
of
the
FWD
f-f
from
the
SLB
to
produce the Servo
Velocity
signal.
During
a Programmed Seek operation, the corresponding
FET
(FWD
or
REV)
will
receive the
Velocity
Ramp Generator signal. The selection
of
one
of
these FET's
is
accomplished
by
the high
or
low Q output
of
the FWD
f-f
which
is
enabled
by
the
FWD/REV
EN
signal
from
the SLB. The
Servo
Velocity
signal
would
then
be
applied
to
the Summing
Amplifier
and the FWD
or
REV Driver
to
develop the Servo
Amplifier
Output
signal
for
carriage positioning.
4.5.5.3
Electronic Tachometer
Network.
This
network
monitors
the Position Transducers
POS
CHANN
E L signal. The
network
senses
the carriage
velocity
and generates a voltage
that
is
applied
to
the
same
two
FET's
as
the
Velocity
Ramp Generator signal. A correction voltage
will
appear
at
the
output
of
the Summing
Amplifier
to
either speed up
or
slow
down
the carriage
to
its intended speed. The
velocity
signal
is
also applied
to
the
LOAD/UN
LOAD
FET's and
controls
those velocities in the
same
manner.
4.5.5.4
Positioner Transducer Signals. These signals
are
routed
to
the
SVA
from
the Positioner
Transducer through the Detent
Amplifier
PWB.
They
are
used
on the
SVA
to
produce the Elec-
tronic
Tach signals, Detent
ODD
and EVEN pulses, Detent
Fault
Detection signal and
for
final
DETENT
operation. The signals
are
called
POS
CHANNEL
1 and
2.
The
DETENT
signal
is
a com-
posite signal derived
from
the
outputs
of
the
photo
diodes in the Positioner Transducer
POS
CHAN
1 and
POS
CHAN
2.
(Generation
of
electronic tach signals
is
explained in the preceding paragraph.)
Detent
ODD
and EVEN pulses
are
generated
by
shaping the
DETENT
signal
into
digital pulses
which
are
used on
the
SLB.
4-35
Page 95
SUPER SERIES
FWD
(-)
(SLB BOARD)
SEEK STROBE
(I/O BOARD)
SK
(+)
(CIB BOARD)
1133-001 B
1~s
---------------
Sl
I
L-
__________________________________________
__
I
Sl
________
_
I
I
DLY
SK
(-)
ISLB
BOARD)
~
lJ,1SEC
I
'-
62
MSEC
..t
I F
APPROX.---~-
I
DET
EN
(+)
(SLB BOARD)
II
--U~------------------~----------------------------
I,
~,
I~------------------~
COARSE SERVO
ENABLE (+)
'-----------------
(SLB BOARD)
POSITION
(TP-5)
(SVA BOARD)
VELOCITY
(TP·3)
(SVA BOARD)
I
I
I
I
"------f...---4-TRACK
63 FOR 100 TPI UNITS
TRACK
126 FOR 200 TPI UNITS
D/A
I
I
CONVE RTE R (TP-2) I
(SVA BOARD)
!
,3
MSEC
SEEKCOMP'
I
-------------------
(CIB BOARD)
L.--
__
----'
Figure 4-24. New Address Seek Operation Waveforms
4-36
Page 96
The Servo
Velocity
signal
is
active
until
the ReadlWrite heads
are
within
one-half track
of
the
address stored in the
NAR.
At
this time, the Detent Enable
(DETENT
EN) signal
is
generated, the
Coarse Servo Loop
is
disabled, and the Fine Servo Loop
is
enabled. The servo detents (locks) the
heads in place over the selected track.
If
the last track
is
even, detenting takes place on the negative
slope
of
the
DETENT
signal.
If
the last address
bit
is
odd, detenting takes place on the positive
slope
of
the
DETENT
signal.
4.5.5.5
Track Offset. The Super Series Disk I)rives have,
as
a customer
option,
the
ability
to
retrieve marginal data.
Two
inputs from the
controller
allow the positioner
to
be
moved a pre-
determined amount, approx. %
mil,
(0.0127 mm) in the desired direction (FWD
or
REV). These
signals
(TRK
OFFSET FWD
or
TRK
OFFSET REV)
are
used
to
recover marginal data during
Read
operations and must
not
be
used
when writing. Offsetting
is
accomplished by injecting a small
current
into
the Detent
circuitry.
4.5.5.6 Beginning
Of
Travel. The BOT pulse
from
the Positioner Transducer
is
amplified and
shaped on
th
is
board before being routed
to
the S LB.
4.5.5.7
Positioning Servo System.
Head
positioning
to
a desired track
is
accomplished by
means
of
the Positioner servo system. This system, a block diagram
of
which
is
shown in Figure
4-25, consists
of a positioner
actuator, a velocity servo loop, a position servo loop, a summing
amplifier, and a servo amplifier. When the spindle
motor
comes up
to
speed, the I
DX
pulses set the
RDY 1 f-f
and
cause
LD HD signal
to
be
generated and the
LOAD/UN
LOAD
line
goes
high. The
FWD signal
is
generated on the Servo Logic Board (SLB) when the
LOAD
f-f
is
set. The
LOAD
(L)
signal
goes
low
causing the FWD
f-f
to
be
reset. Then FWD (L)
goes
low
and
LOAD/UN
LOAD
goes
high, and the Servo
Amplifier
is
activated in the forward direction.
4.5.5.8 Ready I
nhibit.
This signal
is
generated
only
for
200 TPI disk drives.
It
is
the
output
of
the
AMBIENT
TEMP DETECTOR which
is
derived
by
comparison
of
the
two
temperature
sensors
(baseplate and air). When the
two
temperatures
are
equal, the
RDY
INHIBIT
signal
will
be
high allowing the
READY
signal
to
be
sent
to
the
Controller~
This
circuitry
effectively
inhibits
controller
READ
or
WRITE commands
to
the disk drive
until
proper temperature balance
is
a-
chieved.
4-37
Page 97
I
I
I
EXTERNAL
CONTROLLER
{
I
I
I
L_
r:-
FIN~ERVO
I
LOOP
I
L_
__
DETENT
,-
PULSE
GENERATOR
DETENT
- POSITION
SIGNAL SIGNAL
6----
_
_______
CYLINDER
ADDRESS NEW ADDRESS
~...:;:;-::.-~
(9
LINES)"
.....
REGISTER
(NAR)
~
r---
f
~
---
= = = =
MPLIFIER
A
...
--..
SHAPING
NETWORK
CURRENT
ADDRESS
COUNTER
(CAR)
FINE
~
=l-
.-J
---------,
DIFFERENCE
SUBTRACTOR
.--.... (8 LINES)
•
VELOCITY
RAMP
GENERATOR
- t
I
a FET
•
MULTIPLEXER
I
ADDRESS
--
- - - -
la-'lo.
",<y--
~
PRE AMP
DIGITAL
..
ANALOG
CONVERTER
L--.
r--
1134-001
TO
__
-_--
__
FILTER
1
POWER
AMPLIFIER
I
I
I
I
I
I
I
J
_
LINEAR
~
POSITION
TRANSDUCER
L
4.5.6
4.5.6.1
data
to
necessary Write Protect logic
signal paths and
Electronics board (in Volume
4.5.6.2
receptacles mounted on this
matic
are
DATA
Introduction.
and
from
Disk/Head Selection. The
selection diodes. The head activated
ELECTRONICS BOARD (DEB)
The Data Electronics Board contains the
the external Controller on separate
circuit
components
VELOCITY
SIGNAL
~
AMPLIFIER
____
Figure 4-25. Positioner Servo
to
ensure
2)
circuit
that
is
shown in Figure 4-26. Refer
when following the
four
board. The diodes shown
_
Read
data
are
not
erased.
circuit
cable assemblies
is
selected by decoding the HD
POSITIONER9
MOTOR
- - -
circuitry
and Write channels and provides the
A block diagram
to
analysis.
from
the ReadlWrite
next
to
the connectors on the
--
- --
for
processing
of
the DEB showing
the schematic
heads
SE
of
the Data
plug
Land
I/O
into
sche-
DISK
SEL
inputs
used
to
circuit
from
the Controller. The
ground the center
is
shown in Figure 4-27.
point
NAND
of
the selected head. A logic diagram illustrating the decoding
gates
4-38
at the
output
of
the decoder
circuit
are
drivers
Page 98
I
1135·001
HEAD
SEL
DATA
I
INTERFACE
DISK
SEL
BOARD
I
I
}
R/W
HEAD
NO.3
I
I
WRITE
HEAD/DISK
DATA
DATA
X
WRITE
SEI.ECTION
INTERFACE
WRITE
CURRENT
DECODER
BOARD
I
F/F
DRIVERS
WRITE
I
CURRENT
R/W
HEAD
ADJUST
NO.2
I
R/W
HEAD
I
NO.1
READ
DATA
1
r
LOW·
R/W
HEAD
PASS
READ
DATA
2
FIL
TER
NO.O
DATA
INTERFACE
I
BOARD
WRITE
ERASE
WRITE CHECK
X
SERVO
AD256/128
LOGIC
(WRITE
CURRENT
SWITCHING)
BOARD
I
I
OCP
{
R
DISK
WRT PROT
SW
WRT
PROT
F
DISKWRT
PROT
SW
Figure 4-26. Block Diagram
of
Data Electronics Board (DEB)
4-39
Page 99
MULTI-HEAD
SELECT----------tI~~
+13V---4
.......
------..,
DECODING
HEAD
MATRIX
SELECT
B--e_--t
TOP DI SK
--+...,-.._-t
SUMMING
RESISTORS
SELECT
"---
HEAD
SE
LECT
A
--4
___
+...,--+--i
BOTTOM
DISK
SELECT
ERASE
CURRENT-------------------~
BLOCKING
DIODES
READ/
WRITE
HEADS
1136-001
READ/WRITE
HEAD
PIN
FUNCTIONS
~-""--I
3
TO
READ/WRITE
HEAD
(SEE
FIGURE
4-9)
1,3
DATA
READ/
WRITE
PIN
4
CENTER
TAP
PIN
(ENABLES
R/W
HEAD)
5 ERASE
CURRENT
PIN
TO/FROM
READ/
WRITE
CHAIN
Figure 4-27. Disk/Head Selection Decoder
4.5.6.3
Read
Operation. The sinusoidal
output
from
the selected
head
is
amplified
and
shaped
by
two
differential amplifiers and a
filter
network. The outputs, READ
DATA
1 and 2,
are
square
wave pulses which
are
sent
to
the
DI B for
further
processing.
4.5.6.4
Write Operation. The Write data
are
received
from
the external Controller on the
WR
ITE
DATA
line.
It
is
first processed
by
circuitry
on the Data I nterface Board then sent
to
the Write
circuits on the Data Electronics Board (DEB). The WRITE
DATA
signal toggles the Write
f-f;'the
true
or
false outputs of. which
are
routed
to
the
two
.Write current drivers.
See
Figure 4-28. The
f-f
is
enabled
or
disabled by the
output
of
an
AND
gate, and
writing
will
be
inhibited
if
either
or
both
inputs
to
this
gate
are
low. One
input
will
be
low
if
the WRITE signal (developed
from
the
WR
ITE
GATE)
is
low
as
determ ined by the Controller. The other
input
will
be
low
under the
following
conditions:
4-40
Page 100
WRITE
AMPLIFIER
CHAIN
TO
HEADSI
.
READ
1137-001
CHAIN
WRT
DATA
WRT
CURRENT------~--
WRITE
FLIP-
FLOP
__
FILTER
~---I~
~-1p.
READ
READ
DATA
DATA
1
2
Figure 4-28. Block Diagram
A. The fixed disk PROT
is
selected.
B.
The removable cartridge PROT
disk
is
selected.
C.
The
SP
more ReadlWrite
D.
Write
DETEC
Inhibit
input
heads
from Control Interface Board (CIB)
Combinations
taneously
be
selected at the
except A
of
FIXED
Read/\Nrite
switch on the
CART
switch
Amplifier
OCP
is
is
depressed
depressed
from the Disk Control Board (DCB)
are
selected simultaneously.
is
low.
NOTE
of
A,
B, C or D can
and
B (Both disks cannot
same
time.)
occur simul-
and
the fixed disk
and
the removable
is
high and/or
two
or
4-41
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