PET48PX Motherboard Settings and Configuration

Processor

80486SX//80487SX/80486DX/ODP486SX/80486DX2

Processor Speed

20/25/33/50(internal)/50/66(internal)MHz

Chip Set

OPTI

Max. Onboard DRAM

128MB

SRAM Cache

64/128/256KB

BIOS

AMI

Dimensions

330.2mm x 218.4mm

I/O Options

None

NPU Options

4167

CONNECTIONS

Purpose

Location

Purpose

Location

IDE interface LED (input)

J4

Reset switch

J5/pins 9 & 19

Speaker

J5/pins 1-4

IDE interface LED (output)

J5/pins 10 & 20

Turbo switch

J5/pins 7 & 17

Power LED & keylock

J5/pins 11 - 15

Turbo LED

J5/pins 8 & 18

Note: Connect the chassis HD LED to J1/pins 10 & 20 then connect the hard drive LED jumper on the drive controller to J4.

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

Monitor type select color

JP5

closed

Monitor type select monochrome

JP5

open

»

EISA mode select CHRDY

JP7

open

EISA mode select EXRDY

JP7

closed

Note: Some older EISA cards use EXRDY (JP7 closed) to signal the completion of an ISA slave cycle.

DRAM CONFIGURATION

Size

Bank 0

Bank 1

4MB

(4) 1M x 9

NONE

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

64MB

(4) 16M x 9

NONE

128MB

(4) 16M x 9

(4) 16M x 9

SRAM CONFIGURATION

Size

Max. Cacheable

Cache

Location

TAG (U39)

TAG (U41)

TAG (U50)

64KB

32MB

(8) 8K x 8

Banks 0 & 1

(1) 8K x 8

(1) 16K x 1

(1) 16K x 1

128KB

64MB

(4) 32K x 8

Bank 0

(1) 8K x 8

(1) 16K x 1

(1) 16K x 1

256KB

128MB

(8) 32K x 8

Banks 0 & 1

(1) 32K x 8

(1) 16K x 1

(1) 16K x 1

Note:U41 & U50 will accept 64K x 1 or 16k x 1 chips in all configurations. When installing chips in sockets U41 & U50 the chips should be inserted into the socket from the side opposite pin 1. (Pin 1 of the chip still faces pin 1 of the socket.) With a 16K x 1 chip this will leave 2 empty holes on the side of pin1. This is normal. (see diagram below)

SRAM JUMPER CONFIGURATION

Resistor

64KB

128KB

256KB

RNA1

closed

open

open

RNB1

open

closed

open

RNC1

open

open

closed

RNA2

closed

open

open

RNB2

open

closed

open

RNC2

open

open

closed

CPU RESISTOR NETWORK CONFIGURATION

CPU

RNA3

RNB3

RNC3

80486SX

open

open

closed

80487SX

open

closed

open

80486DX

closed

open

open

ODP486SX

open

closed

open

80486DX2

closed

open

open

CPU SPEED CONFIGURATION

CPU

iOSC

JP1

JP2

JP3

JP4

W4

W7

W8

W13

W14

20MHz

40MHz

2 & 3

1 & 2

1 & 2

2 & 3

closed

closed

open

open

open

25MHz

50MHz

1 & 2

1 & 2

1 & 2

2 & 3

open

open

open

open

open

33MHz

66MHz

1 & 2

1 & 2

2 & 3

2 & 3

open

open

closed

open

open

50iMHz

50MHz

1 & 2

1 & 2

1 & 2

2 & 3

open

open

open

open

open

50MHz

50MHz

1 & 2

2 & 3

2 & 3

1 & 2

open

open

open

open

open

66iMHz

66MHz

1 & 2

1 & 2

2 & 3

2 & 3

open

open

closed

open

open

Note: Pins designated should be in the closed position.