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

Track-to-track
seek time Average seek time Full-stroke seek time Average latency
3.5 msec typ
4.0 msec max 12.0 msec typ 14.0 msec max 30.0 msec typ 32.0 msec max 6.67 msec
Note. Host overhead varies between systems and cannot be specified.
Driveinternaloverheadis measuredbyissuinga no-motionseek.
Overheadis typically less than 0.5 msec.
1.3.1 Thermal compensation
Thethermalcompensationfeature compensatesforpositionoffsetof the
selected head because of variationsin temperature. The drive automat-
ically compensates for thermal offset every 30 seconds for the first 30
minutes of operation and every 1.5 minutes thereafter. The drive per-
forms this automatic compensationwhile executing acommand from the
computer.
You can pre-empt the automatic compensation by issuing a Recalibrate
command. The drive performs a thermal compensation, sets a timer and
waits 2 minutes before performing the automatic compensation again.
Thermal compensation increases the execution time of the command
during which it is performed by 100 msec (typ) to 350 msec (max).
1.3.2 Multisegmented cache buffer
The drive uses the cache buffer to improve performance by eliminating
access times under certain conditions. The cache buffer contains four
64-Kbyte segments of RAM (one for writing and three for reading) for a
total capacity of 256 Kbytes.
Readlook-ahead. The drive uses the read segments to store additional
logical sectors, after the last requested sector, into a buffer before the
additional sectors are requested by the computer. The cache buffer
storesdatafrom the start of a read untilthe buffer segment is full, oruntil
another command is received from the computer.
Write immediate. The drive uses the write segment to store write
commands and data. After the drive receives all the data for the com-
mand, it issues a write complete. Then, the drive writes the data to the
disc.
Write merging. The drive accepts contiguous write commands and
executes them as one command.
ST3655 Family AT Drives Product Manual, Rev. A 3

1.4 Start/stop time
Within 20 seconds after DC power is applied, the drive is ready. Within
15 seconds after DC power is removed, the drive spindle stops rotating.
1.5 Typical power-up and power-down sequence
The typical power-up and power-down sequencesassist you in evaluat-
ing the drive’s performance; they are not performance specifications.
1.5.1 Power-up sequence
1. Power is applied to the drive.
2. When poweris applied, the LED is on for about 1 second.
3. The spindle motor reaches operating speed in about 4 seconds.
4. The arm-lock solenoid releases the arm, making an audible sound.
5. The drive performs velocity adjustment seeks.
6. The heads are positioned over track 0 and the drive is ready.
1.5.2 Power-down sequence
Caution. Donot move the driveuntil the motor hascome to a complete
stop.
1. The poweris turned off.
2. Within 3 seconds, the motor begins to spin down.
3. The read/write heads automatically move to the shipping zone,which
is inside the maximum data cylinder.
4. The arm-lock solenoid locks the arm, making anaudible sound. This
completes the power-down sequence.
1.5.3 Auto-park
Upon power-down, the read/write heads automatically move to the
shipping zone. The heads park inside the maximum data cylinder and
the arm-lock solenoid engages, making an audible sound. When power
is applied, the heads recalibrate to track 0.
4 ST3655 Family AT Drives Product Manual, Rev. A

1.6 Reliability
Readerrorratesaremeasuredwithautomaticretriesanddatacorrection
with ECC enabled and all flaws re-allocated. The mean time between
failures (MTBF) is measured at nominal power at sea level and an
ambient temperature of 40°C.
Nonrecoverable read errors 1 per 1013 bits transferred
Seek errors 1 per 107physical seeks
MTBF 250,000 power-on hours
Service life 5 years
1.7 Physical dimensions
The mounting dimensions are shown in Figure 8 on page 24.
Height, max 1.00 inch (25.4 mm)
Width, max 4.02 inches(102.1 mm)
Depth, max 5.77 inches(146.6 mm)
Weight 1.5 lb (0.68 Kg)
1.8 Environmental specifications
1.8.1 Ambient temperature
Operating 5°C to 55°C (41°F to 131°F)
Nonoperating –40°C to 65°C (–40°F to 149°F)
1.8.2 Temperature gradient
Operating 20°C per hour (36°F per hour)
Nonoperating 30°C per hour (54°F per hour)
1.8.3 Altitude
Operating –1,000 ft to 10,000 ft (–305 m to 3,048 m)
Nonoperating –1,000 ft to 40,000 ft (–305 m to 12,192 m)
ST3655 Family AT Drives Product Manual, Rev. A 5

1.8.4 Relative humidity
Operating 8% to 80%noncondensing
Maximum wet bulb 26°C (79°F)
Maximum operating
gradient 10% per hour
Nonoperating 5% to 95%noncondensing
Maximum wet bulb 26°C (79°F)
1.9 Acoustics
Sound pressure is measured from 1 meter above the drive top cover at
idle.
Sound pressure, typ (dBA) 34
Sound pressure, max (dBA) 38
1.10 Shock and vibration
All shock and vibration specifications assume that the drive is mounted
in a recommended orientation (see Figure 7 on page 23) with the input
levelsmeasuredatthedrivemountingscrews.Shockmeasurementsare
based on an 11 msec, half sine wave shock pulse, not to be repeated
more than twice per second.
During normal operating shock and vibration, there is no physical dam-
age to the driveor performancedegradation. Duringnonoperatingshock
and vibration, the read/write heads are positioned in the shipping zone.
Operating Nonoperating
Shock 2 Gs 75 Gs
5–22 Hz vibration 0.020-inch
displacement 0.020-inch displacement
22–500 Hz vibration 0.50 Gs 4.00 Gs
6 ST3655 Family AT Drives Product Manual, Rev. A

1.11 DC power
Except duringthe write procedure, you can turn off and turn on power to
the drive in any sequence without losing data or damaging the drive. If
you turn off the power duringthe write procedure,you may lose the data
currently being written.
1.11.1 Input noise
+5V +12V
Voltage tolerance
(including noise) ±5% ±5%
Input noise frequency
(max) 25 MHz 25 MHz
Input noise
(max, peak-to-peak) 100 mV 240 mV
1.11.2 Power management
This drive uses power-management modes to reduce its overall power
consumption. The level of drive activity for each power-management
mode is described below.
You can customize the power-management modes using the AT inter-
face commands that control the power modes. These commands are
described in the
Seagate ATA Interface Reference Manual , publication
number 36111-
xxx .
Note. If you install one of thesepower-management drives as a slave to
a master drive that does not support power management (for
example, a Seagate ST1239A drive), do not use power-manage-
ment commands on either drive.
1.11.3 Idle and standby timers
The drive can enterthe Idle orStandbymodesby either of two methods:
•The computer can send either the Idle Immediate command or the
Standby Immediate command.
•The idle timer or the standby timer can count down to zero.
At power-on, the drive sets the idle timer to enter the Idle mode after
5 seconds of inactivity; the standby timer is disabled. You can set the
timer delays using the system setup utility. During each read, write or
ST3655 Family AT Drives Product Manual, Rev. A 7

seek, the drive reinitializes the idle timer and beginscounting downfrom
the specified delay to zero.
If the idle timer reaches zero before the drive is commanded to read,
write or seek, the drive switches to the Idle mode. Then, if the standby
timer is enabled, the standby timer begins counting down. After the
standbytimer has finishedcountingdown, thedrive switches to Standby
mode. To set the idle and standby timers, refer to the Idle command in
the
Seagate ATA Interface Reference Manual , publication num-
ber 36111-
xxx .
InboththeIdleandStandbymodes,thedriveacceptsallcommandsand
returns to the Seeking or Read/write modes any time disc access is
necessary.
1.11.4 Power-management modes
The following power-management modes are supported by the drive:
•Spinup. The drive bringsthespindleanddiscs uptooperating speed.
Power in this mode is defined as the average power during the first
10 seconds after starting spinup. The drive enters this mode during
startup and from the Standby mode.
•Seeking. The drive moves the read/write heads to a specificlocation
on the disc surface in preparation for reading or writing the disc.
Read/write electronics are powered down and servo electronics are
active. The power measure during this mode is the average power
while executing random seeks with a 2-revolution (26.6 msec) dwell
between Seek commands.
•Read/write. The drive readsor writesthe disc.Read/writeelectronics
are active and the servo is on track. The drive enters this mode from
the Idle mode.
•Idle. The spindle is spinning and the cache buffer remains enabled,
and the drive accepts all commands and returns to the Seeking or
Read/write modes when it receives a command that requires disc
access.
•Standby. The spindle is stopped,the headsare parked in the landing
zone, the actuator is latched, and some of the drive electronics are
powered down. The drive reports to the computer that it is ready to
access the disc. When the drive receives a command that does not
require disc access, the drive remains in the Standby mode. When
the drive receives a command that requires disc access, it spins up
and performs the command.
8 ST3655 Family AT Drives Product Manual, Rev. A

1.11.5 Power consumption
Inthetablebelow,thevaluesapplyatthedrivepowerconnector.Current
was measured with an RMS DC ammeter.
Spinup Seeking Read/ write Idle Standby
Current at +12V
Amps peak 1.90 — — — —
RMS amps typ — 0.408 0.241 0.208 0.025
Watts typ — 4.90 2.90 2.50 0.30
Current at +5V
RMS amps typ — 0.140 0.500 0.130 0.120
Watts typ — 0.70 2.50 0.65 0.60
Power
Total watts typ 7.00 5.60 5.40 3.15 0.90
ST3655 Family AT Drives Product Manual, Rev. A 9

The startup current profile of each drive is unique. A typical startup
current profile is shown in Figure 1.
T1 Power is applied to the drive.
T2 After a delay, the startup current is applied and the spindle
begins to turn.
T3 The accelerating current is applied,causing the spindle speed to
increase.
T4 The spindle speed is close to the final correct value. The drive
begins to lock in speed-control circuits.
T5 The arm-lock solenoid releases the arm.
T6 The final speed-control lock is achieved.
T7 The drive performs velocity adjustment seeks.
T8 The heads are positioned over track 0, and the drive is ready.
T1
T2
T3 T5
T4
T6
T7
T8
0
1.0
1.7
2.0
0 21 43 65 87
amps
Seconds
Figure 1. Typical startup current profile
10 ST3655 Family AT Drives Product Manual, Rev. A

1.12 Agency listings
This drive is listed by agencies as follows:
•Recognized in accordance with UL 478 and UL 1950
•Certified to CSA C22.2 No. 220-M1986 andCSA C22.2 No. 950
•Certified to VDE 0805/05.90 and EN 60950/1.88 as tested by VDE
1.13 FCC verification
ST3655 family AT interface drives are intended to be contained solely
within a personal computer or similar enclosure (not attached to an
external device). As such, a drive is considered to be a subassembly
evenwhenindividually marketed to the customer. As a subassembly, no
Federal Communications Commission authorization, verification or cer-
tification of the device is required.
Seagate Technology, Inc. has tested these drives in an enclosure as
described above to ensure thatthe totalassembly (enclosure,disc drive,
motherboard, power supply, etc.) does comply with the limits for a
Class B computing device, pursuant to Subpart J of Part 15 of the FCC
rules. Operation with noncertified assemblies islikely to resultin interfer-
ence to radio andtelevision reception.
Radioandtelevisioninterference.Thisequipmentgeneratesanduses
radiofrequencyenergyand, if notinstalledand usedin strictaccordance
withthemanufacturer’sinstructions,maycauseinterferencetoradioand
television reception.
This equipment is designed to provide reasonable protection against
such interference in a residential installation. However, there is no
guarantee thatinterferencewillnotoccurinaparticularinstallation.Ifthis
equipment does cause interference to radio or television, which can be
determined by turning the equipment on and off, you are encouraged to
try one or more of the following corrective measures:
•Reorient the receiving antenna.
•Move the deviceto one side or the other of the radio or TV.
•Move the devicefarther away from the radio or TV.
•Plug the equipment into a different outlet so that the receiver and
computer are on different branch outlets.
ST3655 Family AT Drives Product Manual, Rev. A 11

Ifnecessary,youshouldconsultyourdealeroranexperiencedradio/tele-
vision technician for additional suggestions. You may find helpful the
followingbookletpreparedbytheFederalCommunicationsCommission:
How to Identify and Resolve Radio-Television Interference Problems.
This booklet is available from the Superintendent of Documents, US
GovernmentPrintingOffice,Washington,DC20402.Refertopublication
number 004-000-00345-4.
Note. This digital apparatus does not exceed the Class B limits for radio
noise emissionsfrom computer equipment as set out in the radio
interference regulations of the Canadian Department of commu-
nications.
Le présent appareil numérique n′émet pas de bruits radioélectri-
ques dépassant les limites applicables aux appareils numériques
de Classe B prescrites dans le règlement sur le brouillage ra-
dioélectrique édicté par le Ministère des Communications du
Canada.
Sicherheitsanleitung
1. Das Gerrät ist ein Einbaugerät, das für eine maximale Umegebung-
stemperatur von 55°C vorgesehen ist.
2. Zur Befestigung des Laufwerks werden 3 Schrauben 6-32 UNC-2A
benötigt. Bei seitlicher Befestigung darf die maximale Länge der
Schrauben im Chassis nicht mehrals 3,3 mm und bei Befestigung an
der Unterseite nicht mehr als 5,08 mm betragen.
3. Als Versorgungsspannugen werden benötigt:
+5V ± 5% 0,5A
+12V ± 5% 0,5A (1,9A fur ca. 30 Sek. fur ±10%)
4. Die Versorgungsspannung muβSELV entsprechen.
5. AlleArbeitendürfennurvonausgebildetemServicepersonaldurchge-
führt werden.
6. DerEinbaudes DrivesmuβdenAnforderungen gemäβDIN IEC950V
DC 0805/05.90 entsprechen.
12 ST3655 Family AT Drives Product Manual, Rev. A