Seagate ST251R,ST277R,ST251 Product Manual
ST251/ST251
RIST277R
Product
Manual
February 3, 1987
36035-001,
Revision A
920
Disc Drive, Scotts Valley, CA 95066-4544, USA
Telephone:
408/438-6550.
Telex: 176455 SEAGATE SCVL
c5S»
seagate
Copyright Notice
This manual and all the material contained in
it
are copyrighted with
all rights reserved. This manual may not be copied, in whole
or
in
part, without written consent of
Seagate Technology.
Seagate reserves the right to change, without notice, the specifications
contained
in
this manual.
ii
ST251
1251
RI277R
Product Manual, Rev.A
CONTENTS
1.0 SPECIFICATION SUMMARY
......................
1-1
1.1
Drive
Capacity.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-1
1.1.1
Unformatted Capacity
......................
1-1
1.1.2 Formatted Capacity . . . . . . . . . . . . . . . . . . . . . . . .
1-1
1.1.3 Physical
Organization.
. . . . . . . . . . . . . . . . . . . . .
1-1
1.2
Access Time Definition and
Timing.
. . . . . . . . . . . . . . . .
1-2
1.3
Step Pulse Period and Seek
Method.
. . . . . . . . . . . . . . .
1-2
1.4 Functional
Specifications.
. . . . . . . . . . . . . . . . . . . . . . . .
1-3
1.S
Recording
Methods.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
1.6
Physical Specifications
..........................
1-3
1.7
Reliability
Specifications.
. . . . . . . . . . . . . . . . . . . . . . . . 1-4
1.7.1
Read
Error
Rates . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
1.7.1.1 Bit
Jitter.
. . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
1.7.2 Media
Defects.
. . . . . . . . . . . . . . . . . . . . . . . . . . .
1-4
1.7.2.1
ST2S1
..............................
1-S
1.7.2.2
ST2S1R
.......
, . . . . . . . . . . . . . . . . . . . . .
1-S
1.7.2.3 ST277R .
..
. . . . . . . . . . . . . . . . . . . . . . . . . .
1-S
1.8
Envi ronmental Specifications
.....................
1-S
1.8.1
Ambient Temperature
......................
1-S
1.8.1.1
ST251
..............................
1-S
1.8.1.2 ST251R/277R
........................
1-5
1.8.2 Temperature Gradient . . . . . . . . . . . . . . . . . . . . . . 1-5
1.8.3 Relative
Humidity.
. . . . . . . . . . . . . . . . . . . . . . . . .
1-6
1.8.4 Altitude
Limits.
. . . . . . . . . . . . . . . . . . . . . . . . . . .
1-6
1.8.S
Shock and Vibration
Specifications.
. . . . . . . . . . .
1-6
1.8.S.10peratingShock
...........
..........
1-6
1.8.S.2 Operating
Vibration.
. . . . . . . . . . . . . . . . . . 1-6
1.8.5.3 Nonoperating Shock
..................
1-7
1.8.5.4 Nonoperating Vibration . . . . . . . . . . . . . . . .
1-7
1.9
DC
Power
Specifications.
. . . . . . . . . . . . . . . . . . . . . . . .
1-8
1.9.1
Input Noise Ripple and Frequency
............
1-10
1.9.2 ULlCSA
Certification.
. . . . . . . . . . . . . . . . . . . . . . 1-10
1.10
FCC
Certification
..............................
1-10
1.11
Mounting
Requirements.
. . . . . . . . . . . . . . . . . . . . . . . .
1-11
1.11.1
Shock Mounti
ng
Recommendations
..........
1-11
ST251
/251
RI277R Product Manual, Rev.A
iii
1.11.2 Handling
Precautions.
. . . . . . . . . . . . . . . . . . . . . 1-13
1.11.3 Shipping
Zone............
.....
.........
. 1-13
1.12
Auto-Truncation.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
1.13
Typical Drive Timing
...........................
1-14
2.0 DRIVE
CONFIGURATION.
. . . . . . . . . . . . . . . . . . . . . . . .
2-1
2.1
Drive Configuration Shunt
J7
. . . . . . . . . . . . . . . . . . . . . .
2-1
2.2 Drive
Select
..
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
2.2.1
Daisy-Chain/Radial Drive Configurations
.....
. . 2-2
2.3 Write
Fault
Latch Options:
JP1
and J7 . . . . . . . . . . . . . . . 2-2
2.4 DC-Unsafe Option: JP2
..........................
2-3
2.5 Precompensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
2.6 Life-Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
APPENDIX
A.
MFM/RLL FORMAT
EXAMPLE.
. . . . . . . . . . .
A-1
iv
ST251
1251
RI277R
Product
Manual, Rev.A
LIST OF ILLUSTRATIONS
Figure
1.
Typical +
12
VDC
Start-Up Current Profile
......
1-9
Figure
2.
Typical Power-On Sequence
.................
1-9
Figure
3.
Drive Mounting
Dimensions.
. . . . . . . . . . . . . . . . . 1-12
Figure
4.
Read/Write
Timing.
. . . . . . . . . . . . . . . . . . . . . . . . 1-14
Figure
5.
Buffered-Seek
Timing.
. . . . . . . . . . . . . . . . . . . . . . 1-15
Figure
6.
Auto-Truncation
Timing.
. . . . . . . . . . . . . . . . . . . . 1-15
Figure
7.
Host/Drive Interface Connectors
..............
2-1
ST251
/251 RI277R Product Manual, Rev.A v
vi
ST251
1251
RI277R
Product
Manual,
Rev.A
INTRODUCTION
This manual supports the
ST251
1251
R/277R disc drives. It supercedes
and
replaces the
ST251
Product Manual, 36016-001, Rev.
B.
ST251
1251
RI277R
Product
Manual,
Rev.A
vii
viii
ST251
/251 R/277R Product Manual, Rev.A
1.0 SPECIFICATION SUMMARY
1.1 DRIVE CAPACITY
1.1.1 UNFORMATTED CAPACITY
ST251 ST251R
ST277R
Megabytes Per Drive:
51.2
51.2
76.9
Bytes Per Cylinder: 62,496 62,496
93,744
Bytes Per Track: 10,416 15,624 15,624
1.1.2 FORMATTED CAPACITY
Megabytes Per Drive:
42.8
43.6
65.5
Bytes Per Cylinder: 52,224
53,248
79,872
Bytes Per Track: 8,704 13,312
13,312
Bytes Per Sector: 512
512 512
Sectors
per
Track: 17 26
26
1.1.3 PHYSICAL ORGANIZATION
Tracks: 4,920 3,280
4,920
Cylinders: 820 (0-819) 820 (0-819) 820 (0-819)
Read/Write Heads:
6
4
6
Discs:
3
2
3
ST251
/251 R/277R Product
Manual,
Rev.A
1-1
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