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                         SEAGATE TECHNOLOGY, INC.
                              1-800-SEAGATE
                          http://www.seagate.com
                            (C)opyright 1994



ST-31250W/WC SCSI-2 Fast Wide (Barracuda 2LP)

ÉÍÍÍÍÍÍÍÍÍÍÍ»
º REAR VIEW º  (ST-31250W only)
ÈÍÍÍÍÍÍÍÍÍÍͼ
                                         ÚÄÄÄÄÄ ID 8
                                         ³ÚÄÄÄÄ ID 4
                                         ³³ÚÄÄÄ ID 2
                                         ³³³ÚÄÄ ID 1
               (TOP)                  J5 ³³³³
                 ___________________  ÚÄÄ  Ä1¿/ÍÍÍÍÍÍÍÍÍ\
               Í( ×××××××××××××××××1)ͳ::::::³³ 0 0 0 0 ÆÍ
                 \ÄÄÄÄÄÄÄÄÄÄÄijÄÄÄÄ/  À  ÄÄ  ÙÀÄ5ÄGÄGÄ12Ù
              68 pin I/O CableÙ        ³³
              Connection               ³³   back  o o <--These pins not on
                                       ³³         o o   differential model WD
       Spindle Synch Cable Connector ÄÄÙ³  front  o o   See special WD Term
         (pin-11 SSREF, pin-12 ground)  ³        2 ³ 1  Power detail below
       Remote LED Connector ÄÄÄÄÄÄÄÄÄÄÄÄÙ     ÚÄÄÄÄÙ
        [pin-9 cathode (neg),                 ³
         pin-10 anode (pos)]                  ³
                                              ³
                                              ³
ÚÄ J1 Terminator options (single-ended ONLY) ÄÁÄÄÂÄ (differential) Ä¿
³  o o       o o       o o       o o      ÕoÍo¸  ³                  ³
³  o o       oÕo¸     Õo¸o      ÕoÑo¸      o o   ³    back 1o¸o2    ³
³ ÕoÍo¸      o³o³     ³o³o      ³o³o³      o o   ³         ³o³o     ³
³ 2ÍÍÍ1     2 ÔÍ1     2; 1     2ÍÏÍ1     2   1  ³   front Ô;      ³
³  A         B         C         D         E     ³          C       ³
ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ
  A - Term. power from drive (default)
  B - Term. power to SCSI bus
  C - Term. power from SCSI bus
  D - Term. power to SCSI bus and drive
  E - Enable SCSI terminator (jumper on pins 5-6)


  ÉÍÍÍÍÍÍÍÍÍÍÍ»
  º REAR VIEW º  (ST-31250WC only)
  ÈÍÍÍÍÍÍÍÍÍÍͼ
                     80 pin I/O and DC Power Wall/bracket Connection
                     ³  Female
    J1          /ÄÄÄijÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ\      TOP (HDA)
     ÍÍÍÍÍÍÍÍÍÍ/ ×××××××××××××××××××× \ÍÍÍÍÍÍÍÍÍÍ
              (\Ä1ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ40/)    BOTTOM

     Notes on 80 pin I/O connector:
       pins  1 -  4 = +12v        41 - 44 = 12v GND
            34 - 36 = +5v         74 - 76 = 5v GND
                 37 = SYNC             77 = LEDC
                 38 = MTRON            78 = DLYDST
                 39 = SCSIA0           79 = SCSIA1
                 40 = SCSIA2           80 = SCSIA3

  Mating WC connector: AMP US p/n: 2-557103-1 straight-in, Male 80-pin
                                   2-557101-1 right angle to PCB


  ÉÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ»
  º RIGHT SIDE VIEW º  (ST-31250W/WC)
  ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍͼ


BACK   Õ͸       J2  123456789                   TOP (HDA)  FRONT
 OF   I/OÆÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍPÍWÍAÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ OF
DRIVE  Ô;           :::::::::                   BOTTOM     DRIVE
                     ³³³³³³³³³
      1-2 Reserved ÄÄÁÙ³³³³ÀÁÁÄÄ Reserved 7-9
  3 Parity Disable ÄÄÄÄÙ³³ÀÄÄÄÄÄ Delay Motor Start 6
   4 Write Protect ÄÄÄÄÄÙÀÄÄÄÄÄÄ Motor Start Enable 5



  ÉÍÍÍÍÍÍÍÍÍÍÍÍ»
  º FRONT VIEW º  (ST-31250W/WC)      ÚÄÄÄÄÄÄÄ +5V
  ÈÍÍÍÍÍÍÍÍÍÍÍͼ                      ³ÚÄÄÄÄÄÄ Enable SCSI terminator
                                      ³³ÚÄÄÄÄÄ ID 8
                                      ³³³ÚÄÄÄÄ ID 4
                                      ³³³³ÚÄÄÄ ID 2
                                      ³³³³³ÚÄÄ ID 1   (J4 top row)
                      TOP (HDA)       ³³³³³³1
     ÍÍPÍWÍAÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ͵::::::::::ÆÍÍ  J4
                      BOTTOM      ³³³³³³³³³³
                                  ³³³³³³³³³³          (J4 bottom row)
                        Reserved ÄÁÁÁÙ³³³³³³
                   No connection ÄÄÄÄÄÙ³³³³³
                          Ground ÄÄÄÄÄÄÙ³³³³
         Unit Active LED pin (+) ÄÄÄÄÄÄÄÙ³³³
          SSREF (+) spindle sync ÄÄÄÄÄÄÄÄÙ³³
                   Vendor Unique ÄÄÄÄÄÄÄÄÄÙ³
               Fault LED pin (+) ÄÄÄÄÄÄÄÄÄÄÙ



                            ST-31250W
                            Barracuda 2LP

       UNFORMATTED CAPACITY (MB) ________________1205.3
       FORMATTED CAPACITY (xx SECTORS) (MB) _____1020.9
       AVERAGE SECTORS PER TRACK ________________107 rounded down
       ACTUATOR TYPE ____________________________ROTARY VOICE COIL
       TRACKS ___________________________________18,555
       CYLINDERS ________________________________3,711 user
       HEADS ______PHYSICAL______________________5
       DISCS (3.5 in) ___________________________3
       MEDIA TYPE _______________________________THIN FILM
       RECORDING METHOD _________________________ZBR RLL (1,7)
       INTERNAL TRANSFER RATE (mbits/sec)________47.5 to 72.0
       EXTERNAL TRANSFER RATE (mbyte/sec) _______5 Async
       EXTERNAL TRANSFER RATE (mbyte/sec) _______5.0 to 20 Sync
       SPINDLE SPEED (RPM) ______________________7,200
       AVERAGE LATENCY (mSEC) ___________________4.17
       BUFFER ___________________________________512 KByte
         Read Look-Ahead, Adaptive,
         Multi-Segmented Cache
       INTERFACE ________________________________SCSI-2 FAST Wide
                                                 ASA II
       BYTES PER TRACK __________________________64,160 average
       SECTORS PER DRIVE ________________________
       TPI (TRACKS PER INCH) ____________________4,048
       BPI (BITS PER INCH) ______________________73,820
       AVERAGE ACCESS (ms) (read/write)__________8.0/9.0
         Drive level without controller overhead
       SINGLE TRACK SEEK (ms) ___________________0.6/0.9
       MAX FULL SEEK (ms) _______________________17/19
       MTBF (power-on hours) ____________________800,000
       SHOCK (G's):
                operating (Read/Write) __________2
                nonoperating ____________________50
       ACOUSTICS (typ/max dBA) __________________4.7/
       POWER DISSIPATION (watts/BTUs) Active ____11/35
                                      Idle ______9/31
       POWER REQUIREMENTS: +12V START-UP (amps) _1.26
                           +12V TYPICAL (amps) __0.88 idle
                           +5V START-UP (amps) __0.91
                           +5V TYPICAL (amps) ___0.33 idle
                           IDLE (watts) _________
       LANDING ZONE (cyl) _______________________AUTO PARK
       IBM AT DRIVE TYPE ________________________0 or NONE

       Physical:
                        Height (inches/mm):     1.00/25.4
                        Width  (inches/mm):     4.00/101.6
                        Depth  (inches/mm):     5.75/146.05
                        Weight     (lbs/g):     1.2/545

Already low-level formatted at the factory with 9 spare sectors
per cylinder and 1 spare cylinder per unit.

ZBR = Zone Bit Recording = Variable sectors per track

Seagate reserves the right to change, without notice, product 
offerings or specifications. (05/20/96)

A copy of this specification file may be obtained by FTP at
ftp://ftp.seagate.com/techsuppt/scsi/st31250w.txt.