WD1004-27X Board

Figure 1-1 shows the connector locations (J1, J2, J3, J4, and J5) on the
WD1004-27X board and the location of the jumpers (W17 to W22, R23, and W25
to W28).

The WD1004-27X board has a connector at J4, which allows the controller to
connect power to FileCard drives and jumpers W17 to W22, which permit
selection of additional options.  Also the WD1004-27X board can be used as a
secondary controller.

Figure 1-1. WD1004-27X Connector and Jumper Locations
                                                                   +--------+
                                                                   |     +--+
 +-----------------------------------------------------------------|  o  |
 | o            +--J2----+          +------J1-------+              +-----|
 |   +-J5--+    +--------+          +---------------+      +-------+     |
 |   +-----+    +--J3----+                                 | W17   |     |
 |              +--------+          +--------++-------+    | W18   |     |
 |   +--++--+             +---+     |        ||       |    | W19   |     |
 |   |  ||  |             |   |     |        ||       |    | W20   |     |
 |   |  ||  |             |   |     |        ||       |    | W21   |     |
 |   |  ||  |             |   |     |        ||       |    | W22   |     |
 |   +--++--+             +---+     |        ||       |    +-------+     |
 |      +-----+                     |        ||       |       R23        |
 |      |     |                     +--------++-------+       R24        |
 |      |     |             +-----------+                                |
 |      |     |             |           |                   +-------+    |
 |      |     |             |           |                   | W25   |    |
 |      +-----+             |           |                   | W26   |    |
 |                          +-----------+  +-------------+  | W27   |    |
 |   |  ||  |             |   |     |        ||       |    | W21   |     |
 |   |  ||  |             |   |     |        ||       |    | W22   |     |
 |   +--++--+             +---+     |        ||       |    +-------+     |
 |      +-----+                     |        ||       |       R23        |
 |      |     |                     +--------++-------+       R24        |
 |      |     |             +-----------+                                |
 |      |     |             |           |                   +-------+    |
 |      |     |             |           |                   | W25   |    |
 |      +-----+             |           |                   | W26   |    |
 |                          +-----------+  +-------------+  | W27   |    |
 |                                         |External ROM |  | W28   |    |
 |                                         |Socket       |  +-------+    |
 |                                         +-------------+               |
 |              +J4+                                 +---------+         |
 | o            +--+                                 +---------+      o  |
 +---------------+                                       +---------------+
                 +---------------------------------------+

Jumper Functions (W17 to W22, R23, and W25 to W28)

The following list explains the jumper functions.

  -  W17 & W18 selects factory drive tables for the first
     hard disk

  -  W19 & W20 selects factory drive tables for the second
     hard disk

  -  W21 and W22 selects the controller and BIOS address
     ranges

  -  R23 disables the Western Digital BIOS ROM on WD1004
     and WD1004A boards

  -  W25 and W26 set sector translation and dynamic configuration

  -  W27 sets the hardware interrupt (IRQ) value for the
     hard disk drive

  -  W28 allows the controller to operate with an XT computer
     when the jumper is OUT

Default Values

Tables B-1 through B-5 list the jumper settings. Default factory settings are
marked with a "" symbol.

Table B-1 Pre-selected Drive Tables
-+-------------------------------------------------------------------------
Table     First Drive     Second Drive     Capacity     Heads    Cylinders
Number    W17     W18     W19      W20
-+-------------------------------------------------------------------------
0         in      in      in       in      65MB           6       820
1         out     in      out      in      42MB           4       782
2         in      out     in       out     21MB           2       782
3*        out     out     out      out     32MB           4       615
-+-------------------------------------------------------------------------


Table B-2. Select Controller and BIOS Ranges
-+-------------------------------------------------------------------------
W21       W22            Controller                BIOS
-+-------------------------------------------------------------------------
out*      out*           320-323                   C8000-C9FFF
in        out            324-327                   CA000-CBFFF
out       in             328-32B                   CC000-CDFFF
in        in             32C-32F                   CE000-CFFFF
-+-------------------------------------------------------------------------


Table B-3.  Select BIOS ROM
-+-------------------------------------------------------------------------
R23               Select BIOS
-+-------------------------------------------------------------------------
in                Selects external BIOS
out*              Selects internal BIOS
-+-------------------------------------------------------------------------


Table B-4. Select Sectors and Configuration Option
-+-------------------------------------------------------------------------
W25       W26     Table          Sectors    Translate     Dynamic
-+-------------------------------------------------------------------------
in*        out*   RLL              17         yes           no
out        in     RLL              26         no            yes
-+-------------------------------------------------------------------------


Table B-5. Select Hardware Interrupt (IRQ)
-+-------------------------------------------------------------------------
W27        Select IRQ
-+-------------------------------------------------------------------------
in         selects IRQ2
out*       selects IRQ5
-+-------------------------------------------------------------------------