                         SEAGATE TECHNOLOGY, INC.
       Customer Technical Support FAX Network +1 408 438-8137
     Customer Technical Support Bulletin Boards (300-9600, 8-N-1)
Ŀ
 United States    +1 408 438-8771   United Kingdom +44 628 478011  
Ĵ
 Germany         +49  89 140-9331   Singapore      +65   227-2217  

                            (C)opyright 1995



ST-18771W Ultra SCSI Wide (Barracuda 8)

  ͻ
   REAR VIEW   (ST-18771W only)
  ͼ
        (TOP)                   Auxiliary
          ___________________    1/\
        ( 1)ͳ:::::: 0 0 0 0 
          \ĳ/      5GG12
       68 pin I/O Cable        
       Connection Male          
                                
                                
        Auxiliary option header 
           pin-11 +5v  ٳ
           pin-10 GND  ٳ
           SCSI ID = 8 ٳ
           SCSI ID = 4 Ĵ
            or pin-6 REFIND+ ٳ
           SCSI ID = 2 ٳ
           SCSI ID = 1 
           SCSI ID = 0 (none)


  ͻ
   REAR VIEW   (ST-18771WC only)
  ͼ
                     80 pin I/O and DC Power Wall/bracket Connection
                       Female
    J1          /ĳ\      TOP (HDA)
     /  \
              (\140/)    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 NC connector: AMP US p/n: 2-557103-1 straight-in, Male 80-pin
                                   2-557101-1 right angle to PCB


  ͻ
   SIDE VIEW   (ST-18771W/WC)
  ͼ


BACK   ͸       J2  12345678                    TOP (HDA)  FRONT
 OF    J1PWA OF
DRIVE  ;           ::::::::                    BOTTOM     DRIVE
                     
   Terminator Power ٳ Enable T-Res (not used on WC,WD models)
  ڴTerminator Power ٳ Start Delay (12 secs * ID)
           Reserved ٳ Motor Start
     Parity Disable  Write Protect
  
  
   Ŀ
  Ĵ Termination Power-source Table 
    Ŀ
    ........PWA edge                       
                                        A Drive Supplies Bus  
      1 2     1 2      1 2      1 2     B Drive Supplies Own  
     ķ       ķ                   C Bus Supplies Drive  
                      D Differential only:  
                           Drive Supplies Bus  
       A       B        C        D                            
    Default
    (not used on WC model)
    Note: WD drives do not have internal terminators or any other
          way of adding internal terminators to the drive; use
          external active termination if required.


  ͻ
   FRONT VIEW   (ST-18771W/WC)
  ͼ
                                  ĴReserved. Shipped with cover installed.
                                    Do not remove. Do not install jumpers
                      TOP (HDA)  ͸     1
     PWA͵::::::::::
                 *    BOTTOM     ;123456
                                J6    
            LED                      
                            Remote LED ٳ ID 1
                           (pin-11 +5v)  ID 2
                              Reserved ٳ ID 4
                                          ID 8


                            ST-18771W


       UNFORMATTED CAPACITY (MB) ________________11300
       FORMATTED CAPACITY (MB) __________________8700
       AVERAGE SECTORS PER TRACK ________________ rounded down
       ACTUATOR TYPE ____________________________ROTARY VOICE COIL
       TRACKS ___________________________________
       CYLINDERS ________________________________5,355 user
       HEADS ______PHYSICAL______________________20
       DISCS (3.5 in) ___________________________11
       MEDIA TYPE _______________________________THIN FILM
       RECORDING METHOD _________________________PRML (0,6,6)
       INTERNAL TRANSFER RATE (mbits/sec)________75 to 120
       EXTERNAL TRANSFER RATE (mbyte/sec) _______20 Sync
       SPINDLE SPEED (RPM) ______________________7,200
       AVERAGE LATENCY (mSEC) ___________________4.17
       BUFFER (/optional)________________________512/2048 KByte
         Read Look-Ahead, Adaptive,
         Multi-Segmented Cache
       INTERFACE ________________________________Fast SCSI-2
                                                 ASA II
       BYTES PER TRACK __________________________70,830 to 111,460
       SECTORS PER DRIVE ________________________16,997,187
       TPI (TRACKS PER INCH) ____________________
       BPI (BITS PER INCH) ______________________
       AVERAGE ACCESS (ms) (read/write)__________8.0/9.5
         Drive level without controller overhead
       SINGLE TRACK SEEK (ms) ___________________0.6/1.1
       MAX FULL SEEK (ms) _______________________19/20
       MTBF (power-on hours) ____________________1,000,000
       POWER REQUIREMENTS: +12V START-UP (amps) _2.2
                           +12V TYPICAL (amps) __0.7 idle
                           +5V START-UP (amps) __
                           +5V TYPICAL (amps) ___0.8 idle
                           IDLE (watts) _________12.4
       LANDING ZONE (cyl) _______________________AUTO PARK
       IBM AT DRIVE TYPE ________________________0 or NONE

       Physical:
                        Height (inches/mm):     1.63/41.4
                        Width  (inches/mm):     4.00/101.6
                        Depth  (inches/mm):     5.75/146.1
                        Weight    (lbs/kg):     2.3/1.04

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

ZBR = Zone Bit Recording = Variable sectors per track

Seagate reserves the right to change, without notice, product
offerings or specifications. (11/02/95)

