SEAGATE TECHNOLOGY, INC.
       Customer Technical Support FAX Network +1 408 438-8137
     Customer Technical Support Bulletin Boards (300-9600, 8-N-1)
┌──────────────────────────────────┬─────────────────────────────────┐
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                            (C)opyright 1991



ST-251 ST412 MFM

                                                          /─4─3─2─1─\
                                                          │ O O O O │ Power
              o o o o o o o o                             └─────────┘
  ┌Data Cable o o o o o o o o  ┌Controller Cable    1       5 G G 12
 ═════════ ══ │ │ │ │ │ │ │ │ ════════════════════ ═══   ════════════
              │ │ │ │ │ │ │ │ 1────────────┐
              │ │ │ │ │ │ │ │ └─Terminator─┘
              │ │ │ │ │ │ │ │
Drive Select->1 2 3 4 │ │ │ └ Radial
                │ │ │ │ │ └── Reserved
                │ └┬┘ │ └──── Write Fault
                │  │  └────── Factory Test
                │  └───────── Never Used (Drive Select 3 and 4)
                └ If twisted cable, use Drive Select 2

                          ST - 251

       UNFORMATTED CAPACITY (MB) ________________51.2
       FORMATTED CAPACITY (17 SECTORS) (MB) _____42.8
       ACTUATOR TYPE ____________________________STEPPER
       TRACKS ___________________________________4,920
       CYLINDERS ________________________________820
       HEADS ____________________________________6
       DISCS ____________________________________3
       MEDIA TYPE _______________________________THIN FILM
       RECORDING METHOD _________________________MFM
       TRANSFER RATE (mbits/sec) ________________5.0
       SPINDLE SPEED (RPM) ______________________3,600
       AVERAGE LATENCY (mSEC) ___________________8.3
       INTERFACE ________________________________ST412
       SECTORS PER DRIVE ________________________83,640
       TPI (TRACKS PER INCH) ____________________777
       BPI (BITS PER INCH) ______________________9,935
       AVERAGE ACCESS (ms) ______________________40/28*
       SINGLE TRACK SEEK (ms) ___________________8
       MAX FULL SEEK (ms) _______________________ /70
       MTBF (power-on hours) ____________________100,000
       POWER REQUIREMENTS: +12V START-UP (amps) _2.0/2.5*
                           +12V TYPICAL (amps) __0.5
                           +5V TYPICAL (amps) ___1.0/1.2*
                           TYPICAL (watts) ______11/12*
                           MAXIMUM (watts) ______29/36*
       BUFFERED STEP PULSE RATE (micro sec) _____3-200
       WRITE PRECOMP (cyl) ______________________N/A (821)
       REDUCED WRITE CURRENT (cyl) ______________N/A (821)
       LANDING ZONE (cyl)________________________AUTO PARK
       IBM AT DRIVE TYPE ________________________44, 40, or 3**

       *ST251-0/ST251-1
       **MAY REQUIRE PARTITIONING SOFTWARE

Seagate reserves the right to change, without notice, product
offerings or specifications. (6/26/90)