ABC A3875

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ABC COMPUTER COMPANY, LTD.

A3875

Processor

80386DX

Processor Speed

25/33/40MHz

Chip Set

Forex

Max. Onboard DRAM

32MB

Cache

32/64/128KB

BIOS

AMI

Dimensions

332mm x 218mm

I/O Options

None

NPU Options

80387/3167

File:30148-1.png

CONNECTIONS
Purpose Location Purpose Location

External battery

J3

Turbo switch

J10

Reset switch

J8

Speaker

J11

Turbo LED

J9

Power LED & keylock

J12

USER CONFIGURABLE SETTINGS
Function Jumper Position
�

Monitor type select color

J1

Closed

Monitor type select monochrome

J1

Open

�

External battery select 3.6VDC

J4

Closed

External battery select 6VDC

J4

Open

�

CMOS memory normal operation

J5

Open

CMOS memory clear

J5

Closed

�

NPU mode select synchronous with CPU

J6

pins 1 & 2 closed

NPU mode select asynchronous with CPU

J6

pins 2 & 3 closed

DRAM CONFIGURATION
Size Bank 0 Bank 1

1MB

(4) 256K x 9

NONE

2MB

(4) 256K x 9

(4) 256K x 9

4MB

(4) 1M x 9

NONE

5MB

(4) 256K x 9

(4) 1M x 9

8MB

(4) 1M x 9

(4) 1M x 9

16MB

(4) 4M x 9

NONE

20MB

(4) 1M x 9

(4) 4M x 9

32MB

(4) 4M x 9

(4) 4M x 9

CACHE CONFIGURATION
Size Bank 0 Bank 1 TAG (U41) TAG (U42)

32KB

(4) 8K x 8

NONE

(1) 8K x 8

NONE

64KB

(4) 8K x 8

(4) 8K x 8

(2) 8K x 8

(2) 8K x 8

128KB

(4) 32K x 8

NONE

(1) 32K x 8

NONE

Note: Bank 0 = U44, U46, U48 & U50

CACHE JUMPER CONFIGURATION
Size J7

32KB

pins 1 & 2 closed

64KB

pins 2 & 3 closed

128KB

pins 2 & 3 closed