HwMuseum | Index

WESTERN DIGITAL CORPORATION

WD1002A-WX1

Replaced by the WD1004A-WX1

Data bus: 8-bit, PC/XT

Size: Full-length, full-height card

Hard drives supported: Two MFM 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

USER CONFIGURABLE SETTINGS

Function

Location

Setting

»

BIOS enabled

W3

closed

 

BIOS disabled

W3

open

»

I/O port address 320h

W4

pins 2 & 3 closed

 

I/O port address 324h

W4

pins 1 & 2 closed

»

BIOS ROM size 32K or 64K (hard-wired)

W5

pins 1 & 2 closed

 

BIOS ROM size 16K

W5

pins 2 & 3 closed

»

8 head hard drive with RWC supported

W6

pins 2 & 3 closed

 

16 head hard drive supported (head select 3)

W6

pins 1 & 2 closed

»

x Hard Drive Interrupt is IRQ5 (hard-wired)

W7

pins 1 & 2 closed

 

Hard Drive Interrupt is IRQ2

W7

pins 2 & 3 closed

»

Single controller setting, primary controller

W8

pins 2 & 3 closed

 

Dual controller setting, secondary controller

W8

pins 1 & 2 closed

»

Not used

S1/jumper 5

open

»

Not used

S1/jumper 6

open

»

*Hard Drive Interrupt is IRQ5

S1/jumper 7

open

 

*Hard Drive Interrupt is IRQ2

S1/jumper 7

closed

 

*XT mode enabled

S1/jumper 8

open

 

*AT mode enabled

S1/jumper 8

closed

Note:* This controller can be purchased with several different BIOS revisions.

These jumpers are not applicable when used with some BIOS revisions.

BIOS REVISION "SUPER BIOS" DRIVE TYPE TABLE

 

Drive 0

Drive 1

         

#

S1/1

S1/2

S1/3

S1/4

Cap.

Hds

Cyls.

WP

RWC

0

closed

closed

closed

closed

21MB

4

612

450

450

1

open

closed

open

closed

10MB

4

306

0

153

2

closed

open

closed

open

10MB

2

615

450

450

3

open

open

open

open

21MB

4

615

450

450

BIOS REVISION "G" DRIVE TYPE TABLE

#

Drive 0

Drive 1

         

#

S1/1

S1/2

S1/3

S1/4

Cap.

Hds.

Cyl.

WP

RWC

0

closed

closed

closed

closed

20MB

4

612

none

none

1

open

closed

open

closed

10MB

2

612

128

128

2

closed

open

closed

open

20MB

4

612

128

none

3

open

open

open

open

10MB

4

306

0

none

BIOS REVISION "H" DRIVE TYPE TABLE - S1

JUMPERS 3, 4, & 8 CONFIGURE DRIVE 0

JUMPERS 1, 2 & 7 CONFIGURE DRIVE 1

#

S1/1 & 3

S1/2 & 4

S1/7 & 8

Cap.

Hds

Cyl.

WP

RWC

0

closed

closed

closed

42MB

5

977

none

none

1

open

closed

closed

31MB

5

733

300

none

2

closed

open

closed

33MB

6

640

none

none

3

open

open

closed

62MB

8

1024

1024

1024

4

closed

closed

open

42MB

6

820

none

none

5

open

closed

open

10MB

2

612

128

128

6

closed

open

open

20MB

4

612

128

none

7

open

open

open

10MB

4

306

0

none

MISCELLANEOUS TECHNICAL NOTES

The Super BIOS revision includes the following features not found in other revisions: ability to format bad tracks, dual controller operation, automatic configuration, virtual drive operation, and PC/AT compatibility. 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. Two additional jumpers may be present, W1 & W2, and are reserved for factory use and must not be changed.