
S T 3 7 8 0 A   M E D A L I S T   7 2 0    SEAGATE
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 3.5"/SLIMLINE         Cylinders        | 1399|     |
Capacity form/unform   722/      MB        Heads           4|   16|     |
Seek time   / track  12.0/ 3.5 ms          Sector/track     |   63|     |
Controller           IDE / ATA2 FAST/ENHA  Precompensation
Cache/Buffer           256 KB SEGMENTED    Landing Zone
Data transfer rate    4.500 MB/S int       Bytes/Sector      512
                     16.600 MB/S ext PIO4
Recording method     RLL 1/7                        operating  | non-operating
                                                  -------------+--------------
Supply voltage     5/12 V       Temperature *C         5 55    |    -40 70
Power: sleep              W     Humidity     %         8 80    |      5 95
       standby        1.0 W     Altitude    km    -0.305  3.048| -0.305 12.192
       idle           2.8 W     Shock        g        10       |     75
       seek           6.6 W     Rotation   RPM      4500
       read/write     4.5 W     Acoustic   dBA        33
       spin-up        7.0 W     ECC        Bit   -
                                MTBF         h     300000
                                Warranty Month
Lift/Lock/Park     YES          Certificates     CSA,FCC,UL1950,UL478,VDE     

**********************************************************************
                        L   A   Y   O   U   T
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SEAGATE  ST3780A/ST31220A  PRODUCT MANUAL 36260-001 DRAFT 10, 6/94

  +---------------------------------------------------------++-+
  |                                                         |+-+J5
  |                                                         |
  |                                                         |XX
  |                                                         |XX I
  |                                                         |XX N
  |                                                         |XX T
  |                                                         |XX E J1
  |                                                         |XX R
  |                                                         |XX F
  +--J8                                                     |XX A
  |  |                                                      |XX C
  |  |                                                      |XX E
  |  |                                                      |XX
  +--1                                                      |  1
  |                                                         |XX J3
  |                                                 +--J6   |XX
  +-------------------------------------------------+--+----+



**********************************************************************
                      J   U   M   P   E   R   S
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SEAGATE  ST3780A/ST31220A  PRODUCT MANUAL 36260-001, DRAFT 10, 6/94

 Jumper Setting
 ==============

 Jumpers
 -------
 You can connect two drives to a daisy-chain cable if both drives meet
 the same interface specifications. In a dual-drive configuration, one
 drive is designated as the master (drive 0) and the other as the
 slave (drive 1).

 If you intend to use the cable select option in a dual-drive system,
 before continuing you should determine whether your system supports
 it. See your computer documentation for details.


 Jumper sizes
 ------------
 The jumper blocks use 0.1-inch configuration jumpers. Use Seagate
 part number 10562-001 or an equivalent. The drive is shipped with
 spare jumpers which may be used on any jumper block.

 CAUTION
 If you try to install a jumper that is not the correct size, you
 could damage the jumper and the jumper block pins.


 J5  Master/Slave jumper block
 -----------------------------

    --+---+--Circuit board
      |o 1|
      |o o|  No jumper = One drive only
      +---+


    --+---+--Circuit board
      |xxx|
      |o o|  Spare - as shipped
      +---+


    --+---+--Circuit board
      |o X|
      |o X|  Drive is slave
      +---+


    --+---+--Circuit board
      |X 1|
      |X o|  Drive is master with slave present
      +---+


    --+---+--Circuit board
      |X X|
      |X X|  Cable select. You must also install a jumper on pins 6
      +---+  and 8 of J8.

 Your drive is shipped with a jumper in a spare location on pins 1 and
 3 of the master/slave jumper block. If you are installing only one
 drive, you can leave the jumper installed on pins 1 and 3, or you can
 remove all jumpers from the jumper block.

 You can install up to two drives in a standard AT system. If you are
 installing two drives in your system, configure one drive as the
 master and the other as the slave according to the following guide-
 lines:

 - To configure the drive as a master with a slave present, install a
   jumper on pins 3 and 4 only of the master/slave jumper block of the
   master drive.

   NOTE
   If both the master and the slave are ST31220 family drives, you do
   not need to install a jumper on pins 3 and 4. This is because the
   master can detect the presence of the slave using the DASP- signal
   on the AT interface cable. If the drives in your application do not
   implement the DASP- signal, install the jumper on pins 2 and 4 of
   the master/slave jumper block on the master drive only.

 - To configure the drive as a slave, install a jumper on pins 1 and 2
   only of the master/slave jumper block on the slave drive.

 With the aid of a special interface ribbon cable, the cable select
 option allows you to determine the master and slave according to
 where the drives are plugged into the cable.



 J6  Dual-drive emulation jumper block
 -------------------------------------

    --+--1+--Circuit board
      |xxx|
      |o o|  Spare - as shipped
      +---+

    --+--1+--Circuit board
      |X X|
      |X X|  Dual-drive emulation mode
      +---+

 With jumpers installed on pins 1 and 2, and pins 3 and 4 of jumper
 block J6 you can install this drive as both C and D drives
 simultaneously. Under dual-drive emulation, capacities are as
 follows: for the ST31220A, each subdrive has a capacity of 528 MB for
 a total of 720 MB.

 Installation in this manner causes the drive to appear to your system
 as two drives, master and slave, so an additional slave drive cannot
 be added.

 NOTE
 When the drive is configured with dual-drive emulation, both emulated
 drives respond as one to any power-management command.

 J8  Options jumper block
 ------------------------

  --+-------------1-+--Circuit board
    | o o o o o   X |
    | o o o o o o X | Spare - as shipped
    +14-------------+


  --+-------------1-+--Circuit board
    | o o o o o   o |
    | o o o xxx o o | Cable select
    +14-------------+


  --+-------------1-+--Circuit board
    | X o o o o   o |
    | X o o o o o o | Remote LED connection pin 13(-), pin 14(+)
    +14-------------+

 Remote LED connection
 To add an optional remote LED, attach a two-pin, 0.1-inch connector
 to pins 13 (-) and 14 (+) of the options jumper block J8.

 All other pins are reserved, don't use them.


 Cable select option
 -------------------
 If your computer and both of ypur drives support cable select, you
 can use the cable select option to determine the master and slave. To
 configure your drives using cable select, you need to install jumpers
 and use a special cable-select cable as follows:

 - Install jumpers on pins 1 and 2 and pins 3 and 4 of the master/
   slave jumper block J5 and on pins 6 and 8 of the options jumper
   block J8.

 - You must use an interface ribbon cable built to support master and
   slave selection. The cable and its connectors must connect the CSEL
   signal line to pin 28 of the master drive, but not to the slave
   drive. That is, the drive that is plugged into the I/O connector
   connecting the CSEL signal line to pin 28 is the master. The drive
   plugged into the I/O connector, whose pin 28 is open, is the slave.
   Pin 28 of its cable connector is not connected to the CSEL line.



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                      I   N   S   T   A   L   L
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SEAGATE  ST3780A/ST31220A  PRODUCT MANUAL 36260-001, DRAFT 10, 6/94

 Notes on Installation
 =====================


 Mounting the drive
 ------------------
 You can mount the drive in any orientation.

 NOTE
 If you format the drive before mounting in the computer, it is best
 to format it in the same physical orientation it will have when it is
 mounted.

 Use the set of mounting guidelines below taht are appropriate to the
 type of mounting holes used: either bottom mounting holes or side
 mounting holes.

 Mounting with the optional 1-inch faceplate adds 0.180 inches   0.010
 inches (4.572 mm   0.254 mm) to the overall drive length.

 Bottom mounting holes
 Insert four 6-32 UNC screws in the four bottom mounting holes.

 CAUTION
 Do not insert the bottom mounting screws more that 0.20 inches (6
 turns) into the drive frame. If you use a screw that is too long, you
 risk damaging the drive's circuit board.

 Side mounting holes
 Use four 6-32 UNC screws in four of the six available side mounting
 holes. Use two mounting holes on each side of the drive.

 CAUTION
 Do not insert the side mounting screws more than 0.20 inches (6
 turns) into the drive frame. If you use a screw that is too long, you
 risk damaging the drive's circuit board.




 I/O cable and connector
 -----------------------
 The I/O connector is a 40-pin connector. The even pins are next to
 the edge of the printed circuit board; the odd pins are away from the
 printed circuit board. Pin 1 is near the 4-pin power connector.

 There is no pin 20 because that location is used as a key. Make sure
 the corresponding pin hole on the cable connector is plugged to
 prevent the connector from being installed upside down. The I/O cable
 cannot be longer than 18 inches (0.46 meters).

 The table below lists recommended parts for the mating connector. You
 can use equivalent parts.

 Part       |Description     |3M part number
 -----------+----------------+--------------
 Connector  |40-pin          |3M-3417-7000
 Connector  |40-pin          |3M-3448-2040
 Flat cable |AWG28 (stranded)|3M-3365-40



**********************************************************************
                      F   E   A   T   U   R   E  S
**********************************************************************
SEAGATE  ST3780A/ST31220A  PRODUCT MANUAL 36260-001, DRAFT 10, 6/94


 Formatted capacity
 ------------------
 The drive was low-level formatted at the factory. You cannot low-
 level format it.

 The drive was configured in translation mode at the factory. You can
 verify the number of cylinders, sectors per track and heads, and the
 total number of sectors by using the Identify Drive (ECh) command.

 The amount disc space which your system will access depends on the
 type of system that you have and on the type of operating system or
 third-party installation software that is used to high-level format
 ST31220 family drives.

 One of two addressing schemes may be used by your computer to access
 a hard disc - logical block addressing (LBA) or cylinder-head-sector
 addressing (CHS). LBA allows you to access the full capacity of your
 hard disc. CHS, which is used on older DOS systems, will limit the
 capacity of your hard disc to 1,024 cylinders (approximately 512 MB)
 unless:

 - You are using third-party installation software which supports more
   than 1,024 cylinders

 - You have installed the dual-drive emulation option

 - You have a host adapter (controller card) which supports more than
   1,024 cylinders.

 The following equation holds:

 (sectors) x (heads) x (cylinders)   total sectors per drive


 Multisegmented cache buffer
 ---------------------------
 The drive uses the 256-Kbyte multisegmented cache buffer to improve
 performance by eliminating access times under certain conditions.

 Read look-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 stores data
 from the start of a read until the buffer segment is full or until
 another command is received.

 Write immediate
 The drive uses the write segment to store write commands and data.
 After the drive receives all of the data for the command, 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.


 PIO and DMA Data Transfer Modes
 -------------------------------
 You can use the Set Features command to set the type of data transfer
 mechanism and transfer mode used by the drive. To do this:

 1. Write Set Features command value 03H (Set Data Transfer mode) to
    the Features register.

 2. Write a transfer types value to the Sector Count register. The
    upper 5 bits of this value define the type of data transfer, and
    the low order 3 bits encode the mode value. The following table
    identifies allowable transfer types values:

  +----------------------------------------+-----------------------+
  |Data transfer mechanism                 | Transfer types value  |
  +-----------------------------+----------+----------+------------+
  |Mechanism name               |Mode value|Data Upper|Lower 3 bits|
  |                             |          |5 bits    |            |
  +-----------------------------+----------+----------+------------+
  |PIO Transfer Mode (default:  |    2     |  00000   |     000    |
  |Set PIO Mode 2               |          |          |            |
  +-----------------------------+----------+----------+------------+
  |PIO Transfer Mode: Set PIO   |    2     |  00000   |     001    |
  |Mode 2                       |          |          |            |
  +-----------------------------+----------+----------+------------+
  |PIO Flow Control Transfer    |    0     |  00001   |     000    |
  |Mode: Set PIO Mode = 0       |          |          |            |
  +-----------------------------+----------+----------+------------+
  |PIO Flow Control Transfer    |    1     |  00001   |     001    |
  |Mode: Set PIO Mode = 1       |          |          |            |
  +-----------------------------+----------+----------+------------+
  |PIO Flow Control Transfer    |    2     |  00001   |     010    |
  |Mode: Set PIO Mode = 2       |          |          |            |
  +-----------------------------+----------+----------+------------+
  |PIO Flow Control Transfer    |    3     |  00001   |     011    |
  |Mode: Set PIO Mode = 3       |          |          |            |
  +-----------------------------+----------+----------+------------+
  |PIO Flow Control Transfer    |    4     |  00001   |     100    |
  |Mode: Set PIO Mode = 4       |          |          |            |
  +-----------------------------+----------+----------+------------+
  |Multiword DMA Mode           |    0     |  00100   |     000    |
  +-----------------------------+----------+----------+------------+
  |Multiword DMA Mode           |    1     |  00100   |     001    |
  +-----------------------------+----------+----------+------------+
  |Multiword DMA Mode           |    2     |  00100   |     010    |
  +-----------------------------+----------+----------+------------+
  |RESERVED                     |          |  01000   |     nnn    |
  +-----------------------------+----------+----------+------------+
   If the drive does not support a commanded mode, the drive returns
   an Aborted Command error.


