HwMuseum | Index

DISTRIBUTED PROCESSING TECHNOLOGY

PM2021A/90, PM2021A/95

Data bus:

16-bit, ISA (PM2021A/9x)

Size:

Half-length, full-height card

Hard drive supported:

Up to seven SCSI drives

Floppy drives supported:

Two 360KB, 720KB, 1.2MB, or 1.44MB drives (PM2x2x/95 only)

CONNECTIONS

Function

Location

CM4000 Cache Module Connector

P1

CM4000 Cache Module Connector

P2

DM4000 Disk Array Module Connector

P5

4-pin connector-Drive active LED

P6

DM400 Disk Array Module Connector

P7

34-pin control cable connector-floppy drive

P8

50-pin SCSI connector - internal

P10

50-pin SCSI connector - external

J11

DMA TRANSFER RATE

Speed

Jumper Y12

Jumper Y13

Jumper Y14

 

10MB/sec

open

open

open

 

8MB/sec

closed

open

open

 

6.667MB/sec

open

closed

open

 

5.7MB/sec

closed

closed

open

»

5.0MB/sec

open

open

closed

 

4.4MB/sec

closed

open

closed

 

4.0MB/sec

open

closed

closed

 

3.0MB/sec

closed

closed

closed

SCSI ADDRESS

SCSI I.D.

Jumper Y18

Jumper Y25

Jumper Y26

 

0

open

open

open

 

1

open

closed

open

 

2

closed

open

open

 

3

closed

closed

open

 

4

open

open

closed

 

5

open

closed

closed

 

6

closed

open

closed

»

7

closed

closed

closed

INTERRUPT REQUEST

IRQ

Y29

Y30

 

Disabled

open

open

 

IRQ12

open

closed

»

IRQ15

closed

open

 

IRQ14

closed

closed

DMA CHANNEL

DRQ

Y31

Y32

 

DRQ0

open

open

 

DRQ7

open

closed

 

DRQ6

closed

open

»

DRQ5

closed

closed

I/O PORT ADDRESS

Address

Y33

Y35

 

230h

open

open

»

170h

open

closed

 

330h

closed

open

 

1F0h

closed

closed

BIOS ADDRESS

Address

Y36

Y37

 

Disabled

open

open

 

DC00h

open

closed

 

D800h

closed

open

»

C800h

closed

closed

USER CONFIGURABLE SETTINGS

Function

Location

Setting

»

DMA duty cycle is fast

Y15

open

 

DMA duty cycle is slow

Y15

closed

»

SCSI termination enabled

Y16

closed

 

SCSI termination disabled

Y16

open

»

Address LInes SA17-19 and LA17-19 driven

Y19

closed

 

Only Address LInes LA17-19 driven

Y19

open

»

Floppy drive enabled

Y20

closed

 

Floppy drive disabled

Y20

open

»

Bus Mastering enabled

Y24

closed

 

Bus Mastering disabled

Y24

open

»

BIOS ROM size is 8K

Y38

open

 

BIOS ROM size is 16K

Y38

closed

»

External SCSI cable detection disabled

Y39

open

 

External SCSI cable detection enabled*

Y39

closed

»

Controller supplies TERMPWR to SCSI interface 26

Y50

closed

 

TERMPWR not supplied to SCSI Interface 26

Y50

open

STATUS LED'S

LED

Definition

LED 1

Busy

LED 2

Computer Bus Transfer to Adapter

LED 3

Computer Bus Transfer from Adapter

LED 4

Cache Hit

LED 5

Disk Read-Ahead Active

LED 6

Disk Read

LED 7

Disk Write

LED 8

Adapter Reset

LED 9

Interrupt Pending to Computer

LED 10

DRQ Asserted to Computer

MISCELLANEOUS TECHNICAL NOTES

Detection of an external SCSI cable limits the maximum SCSI bus transfer rate to 5MB/sec.

The function of Jumper Y34 is unknown.