WESTERN DIGITAL CORPORATION

WD1004A-WX1

Data bus: 8-bit, PC/AT, PC/AT

Size: Half-length, full-height card

Hard drives supported: Two MFM ST506/412 drives

Floppy drives supported: None

Maximum heads/cyl.: 16 heads and 1024 cylinders

USERS CONFIGURABLE SETTINGS

Function

Location

Setting

»

Hard drive Interrupt request is IRQ5

W27

closed

 

Hard drive Interrupt request is IRQ2

W27

open

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

5-pin connector-DC power

J4

4-pin connector-drive active LED

J5

BIOS DRIVE TYPE TABLE - (WD1004-27X ONLY)

Table #

W17

W18

W19

W20

Cap.

Hds.

Cyls.

 

0

closed

closed

closed

closed

21MB

4

612

 

1

open

closed

open

closed

10MB

4

306

 

2

closed

open

closed

open

10MB

2

615

»

3

open

open

open

open

21MB

4

615

I/O PORT & BIOS ADDRESS

I/O Port Address

BIOS Address

W21

W22

»

320-323h

C8000-C9FFFh

open

open

 

324-327h

CA000-CBFFFh

closed

open

 

328-32Bh

CC000-CDFFFh

open

closed

 

32C-32Fh

CE000-CFFFFh

closed

closed

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.

If the system is not compatible with the Western Digital BIOS, a resistor must be installed at R23 to disable the WD BIOS