Seagate ST3655 User manual

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ST3655 Family:
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ST3390A, ST3550A, ST3655A
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AT Interface Drives
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Product Manual
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ST3655 Family:
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ST3390A, ST3550A, ST3655A
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AT Interface Drives
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Product Manual
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© 1993 Seagate Technology, Inc. All rights reserved
Publication Number: 36244-003, Rev. A
23 December 1993
Seagate®, Seagate Technology®and the Seagate logo are registered
trademarks of SeagateTechnology,Inc. Otherproductnamesaretrade-
marks or registered trademarks of their owners.
Seagate reserves the right to change, without notice, product offerings
or specifications. No part of this publication may be reproduced in any
form without written permission from Seagate Technology, Inc.

Contents
1.0 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Formatted capacity . . . . . . . . . . . . . . . . . . . . . . 1
1.1.1 Recommended logical configuration . . . . . . . . . . . 1
1.1.2 Physical organization . . . . . . . . . . . . . . . . . . . 2
1.2 Functional specifications . . . . . . . . . . . . . . . . . . . 2
1.3 Seek time . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3.1 Thermal compensation . . . . . . . . . . . . . . . . . . 3
1.3.2 Multisegmented cache buffer . . . . . . . . . . . . . . . 3
1.4 Start/stop time . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.5 Typical power-up and power-down sequence . . . . . . . . . 4
1.5.1 Power-up sequence . . . . . . . . . . . . . . . . . . . 4
1.5.2 Power-down sequence . . . . . . . . . . . . . . . . . . 4
1.5.3 Auto-park . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.6 Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.7 Physical dimensions . . . . . . . . . . . . . . . . . . . . . . 5
1.8 Environmental specifications . . . . . . . . . . . . . . . . . 5
1.8.1 Ambient temperature . . . . . . . . . . . . . . . . . . . 5
1.8.2 Temperature gradient . . . . . . . . . . . . . . . . . . . 5
1.8.3 Altitude . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.8.4 Relative humidity . . . . . . . . . . . . . . . . . . . . . 6
1.9 Acoustics . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.10 Shock and vibration . . . . . . . . . . . . . . . . . . . . . 6
1.11 DC power . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.11.1 Input noise . . . . . . . . . . . . . . . . . . . . . . . . 7
1.11.2 Power management . . . . . . . . . . . . . . . . . . . 7
1.11.3 Idle and standby timers . . . . . . . . . . . . . . . . . 7
1.11.4 Power-management modes . . . . . . . . . . . . . . . 8
1.11.5 Power consumption . . . . . . . . . . . . . . . . . . . 9
ST3655 Family AT Drives Product Manual, Rev. A iii

1.12 Agency listings . . . . . . . . . . . . . . . . . . . . . . . 11
1.13 FCC verification . . . . . . . . . . . . . . . . . . . . . . 11
2.0 Configuring and mounting the drive . . . . . . . . . . . . . 13
2.1 Handling and static-discharge precautions . . . . . . . . . 13
2.2 I/O cable and connector . . . . . . . . . . . . . . . . . . 14
2.3 Remote LED connection . . . . . . . . . . . . . . . . . . 15
2.4 Jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.4.1 Jumper sizes . . . . . . . . . . . . . . . . . . . . . . 15
2.4.2 Factory test jumper block (J6) . . . . . . . . . . . . . 15
2.4.3 Master/slave configuration . . . . . . . . . . . . . . . 17
2.5 Cable select option . . . . . . . . . . . . . . . . . . . . . 18
2.6 Spindle synchronization option . . . . . . . . . . . . . . . 20
2.7 Mounting the drive . . . . . . . . . . . . . . . . . . . . . . 22
3.0 AT interface . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.1 Command set . . . . . . . . . . . . . . . . . . . . . . . . 25
3.1.1 Identify Drive command (ECH) . . . . . . . . . . . . . 27
3.1.2 Set Features command (EFH) . . . . . . . . . . . . . 29
3.1.3 Sleep command (99H, E6H) . . . . . . . . . . . . . . 29
3.2 AT Interface connector pin assignments . . . . . . . . . . 29
Appendix. Timing diagrams . . . . . . . . . . . . . . . . . . . . 31
iv ST3655 Family AT Drives Product Manual, Rev. A

Figures
Figure 1. Typical startup current profile . . . . . . . . . . . . . . . 10
Figure 2. AT interface connector . . . . . . . . . . . . . . . . . . 14
Figure 3. Configuration jumpers . . . . . . . . . . . . . . . . . . . 16
Figure 4. Connecting cable-selected drives . . . . . . . . . . . . . 19
Figure 5. Connecting synchronized drives . . . . . . . . . . . . . . 21
Figure 6. Spindle synchronization timing . . . . . . . . . . . . . . 21
Figure 7. Recommendedmounting orientations . . . . . . . . . . . 23
Figure 8. Mounting dimensions . . . . . . . . . . . . . . . . . . . 24
Figure 9. AT interface connector pin assignments . . . . . . . . . 30
Figure 10. Programmed I/O timing without IORDY . . . . . . . . . 31
Figure 11. Programmed I/O timing with IORDY . . . . . . . . . . . 32
Figure 12. Multiword DMA timing . . . . . . . . . . . . . . . . . . 33
ST3655 Family AT Drives Product Manual, Rev. A v

1.0 Specifications
1.1 Formatted capacity
The drive is low-level formatted at the factory. You cannot low-level
format the drive.
ST3390A ST3550A ST3655A
Formatted capacity (Mbytes*) 341.311 452.415 528.482
Total sectors 666,624 883,624 1,032,192
*One megabyte equals one million bytes.
1.1.1 Recommended logical configuration
You can operate the drive using many different logical configurations,
providedthenumberofsectorspertrackdoesnotexceed256.However,
in DOS the numberof sectors per track must beless than or equal to 63.
When establishing the logical configuration, set the number of sectors
per track and the number of heads to satisfy the following relationship:
16 ≤ (sectors per track)(heads) ≤4,096
When you configure the drive in CMOS, the total sectors cannot exceed
the physicalcapacity of the drive. The total sectors is determinedby the
following formula:
totalsectors=(logicalheads)(logicalsectorspertrack)(logicalcylinders)
To maximize the capacityof the drive, the following geometry is recom-
mended:
ST3390A ST3550A ST3655A
Cylinders 768 1,018 1,024
Read/write heads 14 14 16
Sectors per track 62 62 63
The drive is configured in translation mode. You can verify the number
ofcylinders,sectorspertrackandheadsbyusingtheIdentifyDrive(ECH)
command. See Section 3.1.1 for details about the Identify Drive com-
mand.
ST3655 Family AT Drives Product Manual, Rev. A 1

1.1.2 Physical organization
ST3390A ST3550A ST3655A
Read/write heads 3 5 5
Servo heads 1 1 1
Discs 2 3 3
1.2 Functional specifications
Interface AT
Zone Bit Recording method RLL (1,7)
External data burst transfer rate
(Mbytes per sec) 11.1*
Internal data transfer rate
(Mbits per sec) 21.6 to 36.56
Spindle speed (RPM) 4,500 ±0.5%
Cache size (Kbytes) 256
Bytes per sector 512
Recording density, max (BPI) 53,192**
Track density (TPI) 3,000**
*Thedrivesachievethisexternaltransferratewhenusingprogrammed
I/O with IORDY, as shown in Figure 11 on page 32.
** The ST3550A has a recording density of 52,602 bits per inch and a
track density of 2,400 tracks per inch.
1.3 Seek time
Seek timeis a true statistical averageof at least 5,000measurements of
seek time. All measurements are under nominal conditions of tempera-
ture and voltage with the drive mounted horizontally. The specifications
in the table below aredefined as follows:
•Track-to-track seek time is the average of all possible single-track
seeks in both directions.
•Average seek time ismeasured by executing seeks in both directions
between random cylinders.
•Full-stroke seek time is half the time needed to seek from track 0 to
the maximum track and back to track 0.
2 ST3655 Family AT Drives Product Manual, Rev. A