WESTERN DIGITAL CORPORATION

WD1004-27X, WD1004A-27X

Replaces the WD1002-27X and WD1002A-27X respectively

Data bus: 8-bit, PC/AT

Size: Half-length, full-height card

Hard drives supported: 2 RLL ST506/412 drives

Floppy drives supported: None

Maximum heads/cyl.: 16 heads and 1024 cylinders

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

USERS CONFIGURABLE SETTINGS

Function

Location

Setting

»

Hard drive Interrupt request is IRQ5

W27

closed

 

Hard drive Interrupt request is IRQ2

W27

open

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

Table #

W17

W18

W19

W20

Cap.

Hds.

Cyls.

 

0

closed

closed

closed

closed

65MB

6

820

 

1

open

closed

open

closed

42MB

4

782

 

2

closed

open

closed

open

21MB

2

782

»

3

open

open

open

open

32MB

4

615

I/O PORT & BIOS ADDRESS JUMPERS - (WD1004-27X ONLY)

I/O Port Address

BIOS Address

W21

W22

»

320-323h

C800-C9FFh

open

open

 

324-327h

CA00-CBFFh

closed

open

 

328-32Bh

CC00-CDFFh

open

closed

 

32C-32Fh

CE00-CFFFh

closed

closed

SECTORS AND CONFIGURATION OPTION

Table

Sectors

Translate

Dynamic

W25

W26

RLL

17

yes

no

closed

open

RLL

26

no

yes

open

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.