Seagate ST125N User manual

ST125N
ST138N
ST157N
PRODUCT
MANUAL
_______ &)> Seagate

ST125N/ST138N/ST157N
Product Manual
March 2, 1988
36045-001, Rev. C
&)>Seagate
920 Disc Drive, Scotts Valley, CA 95066-4544, USA
Telephone: [phone] Telex: 176455 SEAGATE SCVL

Copyright Notice
(c) Copyright 1988 Seagate Technology Inc.
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
ST125N/138N/157N Product Manual, Rev. C

Table of Contents
1Specification Summary . . • • • . • • • . • • . • . • • • • • • •1
1.1 Drive Capacity . . . . . . . . . . . . . . . . . • . . . . . . . 1
1.1.1 Fonnatted Capacity . . . . . . . . . . . . . . . . . . . .1
1.2 Data Organization . . . . . . . . . . . . . . . . . . . . . . .1
1.3 Access Time Definition
and Timing . . . . . . . . . . . . . .2
1.4 Functional
SpecHlcatlons . . . . . . . . . . . . . . . . . . . .3
1.5 Physical
SpecHlcatlons . . . . . . . . . . . . . . . . . . . . .4
1.6 Rellablllty Specifications . . . . . . . . . . . . . . . . . . . .4
1. 7 Environmental SpecHlcatlons . . . . . . . . . . . . . . . . .4
1. 7.1 Ambient Temperature . . . . . . . . . . . . . . . . . . .4
1. 7.2 Temperature Gradient . . . . . . . . . . . . . . . . . . .4
1. 7 .3 Relative Humidity . . . . . . . . . . . . . . . . . . . . .4
1. 7 .4 Altitude . . . . . . . . . . . . . . . . . . . • . . . . . .5
1.8 Shock and Vibration Specifications . . . . . . . . . . . . . .5
1.8.1 Operating Shock . . . . . . . . . . . . . . . . . . . . .5
1.8.2Operating Vibration . . . . . . . . . . . . . . . . . . . .5
1.8.3 Nonoperating Shock . . . . . . . . . . . . . . . . . . .5
1.8.4 Nonoperatlng Vibration . . . . . . . . . . . . . . . . . .6
1.9
DC Power Specifications .................... 6
1.9.1 Input Noise Ripple and Frequency . . . . . . . . . . . .7
1. 1OMounting Requirements . . . . . . . . . . . . . . . . . . .8
1.1O.1 ShockMounting Recommendations . . . . . . . . . . .8
1.10.2 Handling and Static Discharge Precautions
...... 10
1. 11 1/0 Cable Requirements . . . . . . . . . . . . . . . . . . 1O
1.11.1 Cable .........................• 10
1.11.2Connector Requirements . . . . . . . . . . . . . . . 11
1.12 SCSI Bus Drivers/Receivers . . . . . . . . . . • . . . . . 12
2 General Product Definition ••.•••••••••••••••• 13
2.1 SCSI Interface . . . . . . . . . . . . . . . . . . . . . . . . 13
2.2 Intelligent Disc Drive Configuration . . . . . . . . . . . . . 13
2.2.1 SCSI Bus Address . . . . . . . . . . . . . . . . . . . 15
2.3 ST125N/138N/157N SCSI Commands . . . . . . . . . . . 15
2.4 Error Recovery . . . . . . . . . . . . . . . . . . . . . . . . 16
2.5 Disc Format . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.5.1 Formatting and Defect Management . . . . . . . . . . 17
2.5.2 Sector Interleave . . . . . . . . . . . . . . . . . . . . 17
2.6 Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2. 7 Incoming Inspection . . . . . . . . . . . . . . . . . . . . . 18
ST125N/138N/157N Product Manual, Rev. c
Ill

2.7.1 Enabling the Offline Selftest Routines ......... ·.19
iv ST125N/138N/157N Product Manual, Rev. C

1 Specification Summary
1.1 Drive Capacity
1.1.1 Formatted Capacity
ST125N
Guaranteed Megabytes: 21.3 21.5 18.2
Bytes per Cylinder: 52,224 52,736 44,800
Bytes perTrack: 13,312 13,312 11,264
Bytes perSector: 1,024 512 256
ST138N
Guaranteed Megabytes: 31.8 32.2 27.4
Bytes per Cylinder: 52,224 52,736 44,800
Bytes perTrack: 13,312 13,312 11,264
Bytes perSector: 1,024 512 256
ST157N
Guaranteed Megabytes: 48.2 48.6 41.3
Bytes per Cylinder: 78,848 79,360 67,328
Bytes perTrack: 13,312 13,312 11,264
Bytes per Sector: 1,024 512 256
1.2 Data Organization
ST125N
Guaranteed Sectors: 20,757 . 41,921 71,225
Sectors per Cylinder: 51 103 175
Sectors perTrack: 13 26 44
Diagnostic
R/W Cylinders: 1 1 1
Bytes perSector: 1,024 512 256
ST125N/138N/157NProduct Manual, Rev. C 1

ST138N
Guaranteed Sectors: 31,059 62,933 107,100
Sectors per Cylinder: 51 103 175
Sectors per Track: 13 26 44
Diagnostic R/W Cylinders: 1 1 1
Bytes per Sector: 1,024 512
256
ST157N
Guaranteed Sectors: 47,047 94,860 161,219
Sectors per Cylinder: n 155
263
Sectors per Track: 13
26 44
Diagnostic R/W Cylinders: 1 1 1
Bytes per Sector: 1,024 512
256
1.3 Access Time Definition and Timing
Access time ts atrue statistical average of at least 5000 measurements
of the time It takes to execute the seek speclfted below less overhead.
Overhead ts measured by Issuing a no motion seek from the highest
Logical Block Address (LBA). Seek times are measured by monitoring
the Busy line on the SCSI bus. All measurements assume a block size
of 512 bytes and an ambient temperature of 25° c.
Track-to-track access time Is an average of all possible single track
seekS tn both directions.
Average access time ts measured by executing seek commands from
one random LBA to another.
Maximum (fUll-stroke) access time ts halfthe time needed to seek from
LBA otothe maximum LBA and back to LBA o.
2 ST125N/138N/157N Product Manual, Rev. C

MLC-0 MLC-1
Track-to-Track:
Average:
Maximum (Full-Stroke):
Average Latency:
8 msec. typ.
1O msec. max.
38 msec. typ.
40 msec. max.
90 msec. typ.
95 msec. max.
8.33msec.
8msec.
typ.
1O msec. max.
28 msec. typ.
30 msec. max.
70 msec. typ.
75 msec. max.
8.33msec.
Note: Several factors contribute to overhead time, Including host
and controller overhead. Host overhead varies from one host
to another
and can not be specified. Controlleroverhead Is a
function ofcontroller hardware and firmware and Is typically
less than 3 msec.
1.4 Functional Specifications
ST125N ST138N ST157N
Tracks:
Cylinders:
Read/Write Heads:
1,628
407 (0-406)
4
2,452
615
(0-614)
4
3,678
615
(0-614)
6
Discs:
Rotational
Speed:
Recording Method:
Recording Density (BPI):
Flux Density (FCI):
Track Density (TPI):
Interface:
1/0 DataTransfer Rate:
Int. DataTransfer Rate:
Nonrecoverable Read Errors:
2 2
3,600±0.5%
RLL (2,7)
22,430
14,953
824
SCSI
Up to 1.5 Mbytes/sec.
Up to 7.5 Mblts/sec.
1per 1012 bits read
ST125N/138N/157N Product Manual, Rev. C
3
3

1.5 Physical Specifications
Height:
Width:
Depth:
Weight:
1.63inches max. (41.4 mm)
4.02 inches max. (102.6 mm)
5.77 inches max. (146.6 mm)
1.6lbs. (0.73 Kg.)
1.6 Reliability Specifications
MTBF:
PM:
MTTR:
ComponentDesign Life:
30,000 Power-on hours (Typical usage
at 25°C ambienttemp., sea level)
Not Required
30minutes
5years
1. 7 Environmental Specifications
1.7.1 Ambient Temperature
Operating:
Nonoperating: 10°C to
45° C (50° F to 113° F)
-40° C to 60° C (-40° F to 140° F)
1.7.2 Temperature Gradient
Operating:
Nonoperating:
10° C/hr max. (18° F/hr)
Belowcondensation
1.7.3 Relative Humidity
Operating:
Maximum Wet Bulb:
Nonoperating:
4
8 to 80% noncondensing
26° C (78.8° F) noncondensing
Belowcondensation
ST125N/138N/157N Product Manual, Rev. C

1. 7.4 Altitude
Operating:
-1,000ftto 10,000ft
Nonoperating: -1,000 ft to 30,000 ft
1.8 Shockand Vibration Specifications
All shockand vibration measurements assumethatthedriveis mounted
in an approved orientation with the Input levels at the drive mounting
screws.
Shock measurements are based on an
11 msec. half-sine wave shock
pulse.Thenonoperatlngspecificationsassumethattheread/writeheads
are positioned in the shipping zone atthe inside diameter ofthe disc.
1.8.1 Operating Shock
Maximum permitted shock without incurring physical damage or
degradation in performance: 1OG's
1.8.2 Operating Vibration
Maximumpermitted vibration atthefollowing frequencies, without incur-
ring physical damage ordegradation in performance:
Frequency
5-22 Hz
22-300Hz
300-22Hz
22-5 Hz
1.8.3 Nonoperating Shock
Vibration
0.020 in. double amplitude
0.5 G peak amplitude
0.5 G peak amplitude
0.020 in. double amplitude
Maximum permitted shock without incurring physical damage
or
degradation in performance: 60 G's
ST125N/138N/157N Product Manual, Rev. C 5

1.8.4 Nonoperatlng Vibration
Maximumpermitted vibration atthefollowing frequencies, withoutincur-
ring physical damage
or degradation In performance:
Frequency
5-22 Hz
22-300 Hz
300-22 Hz
22-5 Hz
1.9 DC Power Specifications
Vibration
0.040 in. doubleamplitude
1.00 G peakamplitude
1.00G peakamplitude
0.040 in. doubleamplitude
Powermay be applied
or removed in any sequencewithout loss of data
ordamage to the drive.
Typical seeking/nonseeking current and power specifications assume
nominal voltage applied,
25° e ambient temperature, sea level and
spindlerotating.
Maximum (3
l: max.) seeking and nonseeking current specifications as-
sume 10°eambienttemperature, 5.25 voeand 12.6voeapplied, sea
level and spindle rotating.
6 ST125N/138N/157N Product Manual, Rev. e

+12 voe
Voltage Tolerance (inc. ripple):
Max. Current at Power-Up:
Max. RMS Current at Power-Up (t;;10 sec.):
±5%
2.0Amps
1.5Amps
Seeking Current:
Peak Max.
RMS Max.
RMSTyp.
Nonseeklng Current:
RMS Max.
RMSTyp.
+SVDC
Voltage Tolerance (inc. ripple):
Seeking Current:
Peak Max.
RMS Max.
RMSTyp.
Nonseeking Current:
RMS Max.
RMSTyp.
POWER
PowerTyp.
1.4Amps
0.9Amps
0.6Amps
0.5Amps
0.35Amps
Without Term.
With Term.
±5% ±5%
1.4Amps
1.6Amps
1.2Amps 1.4Amps
1.0Amps 1.2Amps
1.1 Amps 1.3Amps
0.9Amps 1.1 Amps
9Watts 10Watts
1.9.1 Input Noise Ripple and Frequency
Themaximum permitted noiseripple is 100mV (peak-to-peak) on either
+5 or +12 voe measured on the host system power supply across the
following equivalent resistive loads:
+12VOC:
+5VOC:
16 '1
5 '1
Themaximumpermittednoisefrequency is20 MHzon both the+ 12VOC
and +5 voe lines.
ST125N/138N/157N Product Manual, Rev. C 7

Figure 1:Typical RMS Start-Up Current Profile
2.3A ~---------------------.
1.76A 227mV.0.30S
85.6mV. 17..475$
42.SmV. 18.00S .35 A
21.9mV. 6.30S
'---------------------'~-
These measurements are atnominal voltages, 25°Cambient tempera-
ture, with drive termination.
1.10 Mounting Requirements
The drive may be mounted horizontally with the spindle motor down, or
on either side (edge). Mounting vertically on either end is a prohibited
orientation.
The drive should not be tilted (front to back) In any position,
by more than 5°.
For optimum performance the drive should be formatted In the same
orientation as Itwill be mounted In the host system.
1.10.1 Shock Mounting Recommendations
It Is recommended that any external shock mounts between the drive
and the hostframe be designed so thatthe composite system has aver-
tical resonant frequency
of 25 Hz or lower.
A minimum clearance of 0.050 inch should be allowed around the entire
perimeter of the drive to allowfor cooling airflow and mechanical move-
ment during shock or vibration.
8 ST125N/138N/157N Product Manual, Rev. C

Figure 2: Mounting Dimensions
0 10 0
- "' -
000
-H -H -H
10 0 "'
"'
10 10
,.._ 0 "'
- 0 0
0.827
0.559 ±.025
0
-H
0.15 ±.01
(0.020)
2.362 ±.010
5.77 MAX
c ±.025 D ±.010
2.752 ±.010
TABULATION
~
0
-H
0
0
10
0
THREAD TYPEJ_ A J_ B _l C _l D _l E I F
ENGLISH I2.375I1 .750I2.375I1 .750I3.750J_6-32 UNC-2B
METRIC
_1_2.433_1_1. 752_12.433_11. 752_13. 752.IM4 X 0. 7-6H
NOTES:
I. ALL DIMENSIONS, INCLUDING TABULATION,
ARE IN INCHES.
ST125N/138N/157N Product Manual, Rev. C
MOUNTING HOLES ( I 6X l •
8 ON BOTTOM
4 ON EACH SIDE
F X
0.150 DEEP
9

1.10.2 Handling and Static Discharge Precautions
Afterunpackingandpriortosystemintegration,thedrivecanbeexposed
topotential handling and ESD hazards. Itis mandatorythatyouobserve
proper static-discharge precautions and handle the drive by the frame
only.
1.11 110 Cable Requirements
1.11.1 Cable
A SO-conductor flat cable or25-conductortwisted paircable is required.
Themaximumcablelengthis6 meters (19.7
ft). EachSCSIbusconnec-
tion may have a 10 cm (3.9 in) maximum stub length.
The characteristic impedance for unshielded flat or twisted pair ribbon
cable should be 100n ±10%. A characteristic impedance greaterthan
90 n is preferred for shielded cables. To minimize discontinuities and
signal reflections it isdesirableto minimizethe useofcables ofdifferent
impedances in the same bus.
Figure 3: 50 Pin SCSI Connector Pin Assignments
Signal
-08(0)
-08(1)
-08(2)
-08(3)
-06(4)
-06(5)
-06(6)
-06(7)
-06(P)
Ground
Ground
Ground
Terminator Power
Pin Num.
2
4
6
8
10
12
14
16
18
20
22
24
26
Signal
Ground
Ground
-ATN
Ground
-6SY
-ACK
-RST
-MSG
-SEL
-CID
-REQ
-1/0
Pin Num.
28
30
32
34
36
38
40
42
44
46
48
50
Note: All oddpins, except pin-25are connected toground. Pin-25 is not
connected.
10 ST125N/138N/157N Product Manual, Rev. C

Figure 4: Nonshlelded Cable Connector
· t--~---2.880 ±-015 In. (68.07 ±-38 mm)--~--<-1
h--~ ~
Triangle lndtcales
Position One
~ 2.880 ±-015 In. (88.07 ±-38 mm) ;;--I
.100 in. (2.54 mm)I ri3ii5i181"n. (1.52 mm)JdPolarlzing Ke~I
~-~ , ~I~
--l l-.100 In. (2.54 mm) _J L.038 in. (.97 mm)
1.11.2 Connector Requirements
The drive connector is a 50-conductor connector with two rows of 25
male pins on 100 mil centers.
The cable connector is a 50-conductor nonshielded connector consist-
ing
of tworows of 25 femalecontacts on 100milcenters. Recommended
strain-relief connectors are AMP part number 1-499506-2 or DUPONT
part number 66900-X50.
ST125N/138N/157N Product Manual, Rev. C
11

1.12 SCSI Bus Drivers/Receivers
Thedrive useopen collectordrivers. All signals are tenninated with 220
n to +5 voe (nominal) and 330 a to ground. The tenninating resistors
are removable for multi-drive configuration.
Forthesemeasurements, SCSI bustermination
Is assumedtobeexter-
nal to the drive. A typical drive is supplied with the resistor termination
packs installed.
Signals driven by the drive have the following output characteristics,
when measured at thedriveconnector:
Signal true:
Signal false:
o.o voeto o.4 voe
2.5 voeto 5.25 voe
Signals received by the drivemust have the following input characteris-
tics, when measured at the driveconnector:
Signal true:
Maximum total input load:
Signal false:
Minimum Input Hysteresis:
o.o voe to o.s voe
-0.4 mAmps @ 0.4 voe
2.0 voe to 5.25 voe
0.2VOe
12 ST125N/138N/157N Product Manual, Rev. C

2 General Product Definition
TheST125N/138N/157N feature an integralSCSI-compatiblecontroller.
This embedded controller performs all of the functions that were pre-
viously implemented
by an add-on controller. And with the controller on-
board, the diagnosticcapabilities ofthe drive are enhanced becausethe
controller is able to optimize drive performance and error recovery.
2.1 SCSI Interface
The embedded controller supports the SCSI interface as defined in the
ANSI X3T9.2/82-2document. The interfacehardware is capableoftrans-
ferring up to 1
.5 megabytes/second using asynchronous data transfer.
Devices
on the SCSI interface are daisy-chained together using acom-
mon cable. Both ends of the cable are terminated. All signals on the in-
terface
are common between all devices.
Refer to the Seagate
SCSI Interface Manual, 36021-001, for a detailed
discussion of the SCSI interface.
2.2 Intelligent Disc Drive Configuration
The ST125N/138N/157N support four commands which determine and
control the drive's operating environment.
Read Capacity:
Inquiry:
Mode Sense:
Mode Select:
Defines the formatted capacity
Defines the drive type and identifies physical
device parameters
Defines
the drive's current operating environ-
n.ent
Provides a method to change
the operating
characteristics of the drive
The host system
can control the following key parameters:
• Total number of blocks available
• Block length
ST125N/138N/157N Product Manual, Rev. C
13

Figure 5: Host/Drive Interface Connectors
14
RESISTOR
TERMINATION
PACKS
PIN I
J3
DC POWER
PIN I
JI
50-PIN SCSI
C{Nl£CTOR
PIN l
J3
DC POWER ANO
PIN CONNECTOR ASSIGNMENTS
PIN
POllER
I +12 voe
2 + l 2 VOLTS RETURN
3
+5 VOLTS RETURN
4 +5
voe
p 4 2 I
00000
SCSI ID =0
00000
ooooigi
00000
SCSI ID = I
oo oigio
00000
SCSI ID =2
000~
00000
SCSI ID =3
o oigio o
00000
SCSI ID = 4
o oigioigi
SCSI ID =5
00000
2 4 6 8 10
~0000
00~0
SCSI ID = 6
0000
00000
3 5 7 9
00~
SCSI ID = 7
P N/C 4
00000
J2 SCSI ID JUMPERS
SELECT THE DESIRED SCSI ID WITH JUMPERS.
INSTALLING A JUMPER ON PINS I AND 2 ENABLES PARITY.
N/C = NO CONNECT ION
ST125N/138N/157N Product Manual, Rev. C

• Sector lnterteave
• Enable/disableerror
recovery
• Enabllng/dlsabllng reporting of recovered error status
• Enabllng/dlsabllng of reporting usage and errorcounter overflow
2.2.1 SCSI Bus Address
Jumpers are provided on the drive for selecting the SCSI bus address.
The microprocessor accesses thisInformationat power-on. The address
jumpers are accessed only during the power-on sequence. Hthe SCSI
address Is changed, the drive must be powered off and on.
2.3 ST125N/138N/157N SCSI Commands
The commands shown In the Command Summary figure thatfollows are
supported bythe ST125N/138N/157N. Refertothe SeagateSCSI /nter-
faet1 Manua/fora detailed discussion of the SCSI Interface.
ST125N/138N/157N Product Manual, Rev. C 15