ADAPTEC, INC.

ACB-4000A, ACB-4070

Data bus:

None (SCSI to ST506 interface)

Size:

Drive card

Hard drives supported:

SCSI to two RLL ST506 drives

Floppy drives supported:

None

CONNECTIONS

Function

Location

20-pin data cable connector-drive 0

CN0

20-pin data cable connector-drive 1

CN1

34-pin control cable connector-hard drive(s)

CN2

4-pin connector-DC power

CN3

50-pin SCSI connector-to host adapter

CN4

SCSI ADDRESS

SCSI ID

JP5/Jumper 1

JP5/Jumper 2

JP5/Jumper 3

 

0

open

open

open

 

1

closed

open

open

 

2

open

closed

open

 

3

closed

closed

open

 

4

open

open

closed

 

5

closed

open

closed

 

6

open

closed

closed

»

7

closed

closed

closed

USER CONFIGURABLE SETTINGS

Function

Location

Setting

»

Write precomp. disabled (ACB-4000A only)

JP2

pins 1 & 2 closed

 

Write precomp. same as R.W.C. (ACB-4000A only)

JP2

pins 2 & 3 closed

 

Write precomp. to all tracks enabled (ACB-4000A only)

JP2

pins 2 & 4 closed

»

DMA transfer rate is SYSCLOCK/4

JP5/jumper 4

closed

 

DMA transfer rate is DATACLOCK/2

JP5/jumper 4

open

»

Extended command set enable - SASI compatible

JP5/jumper 5

closed

 

Extended command set disabled

JP5/jumper 5

open

»

Not used

JP5/jumper 6

open

»

Supports the SEEK COMPLETE line during head switches

JP5/jumper 7

closed

 

SEEK COMPLETE Cmd. not supported

JP5/jumper 7

open

»

Self-diagnostics enabled

JP5/jumper 8

closed

 

Normal operation

JP5/jumper 8

open

MISCELLANEOUS TECHNICAL NOTES

The function of JP1 is to determine the select technique used to interface the host adapter.

Soldering Pin 2 to Pin "P" allows for the "pulse" select that is used by controllers designed to work with SASI hosts. Soldering Pin 2 to Pin "H" or "L" allows for the "level" select signal used in accordance with SCSI standards.