Western Digital WD1004A-27X Installation Manual page 7

The WD1004 board has a row of jumper pins at W17 to W22 and W25 to W28. The
WD1004A board has a row of jumper pins at W25 to W28. Adding a jumper shorting plug at
any of these locations, selects a hardware configurations that is different from the default
value selected by Western Digital.
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
†
Not available on the WD1004A-27X board
B
JUMPERS
.
B–1