WESTERN DIGITAL CORPORATION
===========================

   WD1002A-27X

   Replaced by the WD1004A-27X

   Data bus: 8-bit, PC/XT

   Size: Half-length, full-height card

   Hard drives supported:  Two RLL ST506/412 drives

   Floppy drives supported: None

   Maximum heads/cyl.: 16 heads and 1024 cylinders

<gopher://bitreich.org/I/th99/c/U-Z/20216-1.png>
   

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   |                 Function                  |    Location    |
   |-------------------------------------------+----------------|
   | 34-pin control cable connector-hard drive |       J1       |
   |-------------------------------------------+----------------|
   | 20-pin data cable connector-drive 0       |       J2       |
   |-------------------------------------------+----------------|
   | 20-pin data cable connector-drive 1       |       J3       |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 USER CONFIGURABLE SETTINGS                 |
   |------------------------------------------------------------|
   | Mode  |        Mode Description        | Jumper | Position |
   |-------+--------------------------------+--------+----------|
   |   |>> | Supports low-level and dynamic |        |          |
   |   |   | low-level formatting. Performs |        |          |
   |   |>> | logical translations; (i.e.-4  |   W1   |  closed  |
   |   |   | hds., 615 cyls. and 26 SPT     |        |          |
   |   | 1 | would be seen by DOS as 4 hds. |   W2   |  closed  |
   |   |   | 940 cyls. 17 SPT. Supports     |        |          |
   |   |   | only up to 16 heads and 663    |        |          |
   |   |   | cylinders (physical).          |        |          |
   |---+---+--------------------------------+--------+----------|
   |   |   | Supports low-level and dynamic |   W1   |   open   |
   |   |   | low-level formatting. Does not |        |          |
   |   | 2 | do logical translation.        |   W2   |   open   |
   |   |   | Supports up to 16 heads and    |        |          |
   |   |   | 1024 cylinders (physical).     |        |          |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |               MISCELLANEOUS TECHNICAL NOTES                |
   |------------------------------------------------------------|
   |  This controller has a built-in low-level format program.  |
   |  To enter the program run the DEBUG utility supplied with  |
   |           DOS and at the prompt enter: G=C800:5.           |
   +------------------------------------------------------------+