STEP 486SX20 (EV-18116) Motherboard Settings and Configuration

Processor

80486SX/80487SX/80486DX

Processor Speed

20/25MHz

Chip Set

C & T

Max. onboard DRAM

32MB

Cache

128/256KB

BIOS

AMI

Dimensions

330mm x 218mm

I/O Options

32-bit external memory card, floppy drive interface, IDE interface, parallel port, serial ports (2)

NPU Options

4167

CONNECTIONS

Purpose

Location

Purpose

Location

Parallel port

CN1

Floppy drive interface

CN5

Serial port (COM1)

CN2

32-bit external memory card

S1

Serial port (COM2)

CN3

Instep socket

U19

IDE interface

CN4

CACHE CONFIGURATION

Size

Max Cachable

Bank 0

Bank 1

128KB

16MB

(4) 32K x 8

NONE

256KB

32MB

(8) 32K x 8

Banks 0 & 1

CACHE JUMPER CONFIGURATION

Size

P1

128KB

pins 2 & 3 closed

256KB

pins 2 & 3 closed

SERIAL PORT 1 CONFIGURATION

COM1

J15/1 & 2

J15/3 & 4

J15/5 & 6

J15/7 & 8

IRQ3

Open

Closed

Open

Open

»

IRQ4

Open

Open

Closed

Open

IRQ5

Open

Open

Open

Closed

IRQ9

Closed

Open

Open

Open

SERIAL PORT CONFIGURATION

COM2

J15/9 & 10

J15/11 & 12

J15/13 & 14

J15/15 & 16

»

IRQ3

Open

Closed

Open

Open

IRQ4

Open

Open

Closed

Open

IRQ5

Open

Open

Open

Closed

IRQ9

Closed

Open

Open

Open

PARALLEL PORT CONFIGURATION

LPT 2

J12/pins 1 & 2

J12/pins 3 & 4

J12/pins 5 & 6

IRQ5

Open

Closed

Open

»

IRQ7

Open

Open

Closed

IRQ9

Closed

Open

Open

CPU TYPE CONFIGURATION

Type

JP1

JP2

JP3

JP4

80486SX

pins 1 & 2 closed

Open

Open

Open

80487SX

pins 2 & 3 closed

Closed

Closed

Open

80486DX

pins 2 & 3 closed

Closed

Open

Closed

DRAM CONFIGURATION

Size

Bank 0

Bank 1

Bank 2

Bank 3

1MB

(4) 256K x 9

NONE

NONE

NONE

2MB

(4) 256K x 9

(4) 256K x 9

NONE

NONE

3MB

(4) 256K x 9

(4) 256K x 9

(4) 256K x 9

NONE

4MB

(4) 256K x 9

(4) 256K x 9

(4) 256K x 9

(4) 256K x 9

4MB

(4) 1M x 9

NONE

NONE

NONE

5MB

(4) 1M x 9

(4) 256K x 9

NONE

NONE

6MB

(4) 1M x 9

(4) 256K x 9

(4) 256K x 9

NONE

7MB

(4) 1M x 9

(4) 256K x 9

(4) 256K x 9

(4) 256K x 9

8MB

(4) 1M x 9

(4) 1M x 9

NONE

NONE

9MB

(4) 1M x 9

(4) 1M x 9

(4) 256K x 9

NONE

10MB

(4) 1M x 9

(4) 1M x 9

(4) 256K x 9

(4) 256K x 9

12MB

(4) 1M x 9

(4) 1M x 9

(4) 1M x 9

NONE

13MB

(4) 1M x 9

(4) 1M x 9

(4) 1M x 9

(4) 256K x 9

16MB

(4) 1M x 9

(4) 1M x 9

(4) 1M x 9

(4) 1M x 9

16MB

(4) 4M x 9

NONE

NONE

NONE

17MB

(4) 4M x 9

(4) 256K x 9

NONE

NONE

18MB

(4) 4M x 9

(4) 256K x 9

(4) 256K x 9

NONE

20MB

(4) 4M x 9

(4) 1M x 9

NONE

NONE

21MB

(4) 4M x 9

(4) 1M x 9

(4) 256K x 9

NONE

22MB

(4) 4M x 9

(4) 1M x 9

(4) 256K x 9

(4) 256K x 9

24MB

(4) 4M x 9

(4) 1M x 9

(4) 1M x 9

NONE

25MB

(4) 4M x 9

(4) 1M x 9

(4) 1M x 9

(4) 256K x 9

28MB

(4) 4M x 9

(4) 1M x 9

(4) 1M x 9

(4) 1M x 9

DRAM CONFIGURATION CON'T

32MB

(4) 4M x 9

(4) 4M x 9

NONE

NONE

33MB

(4) 4M x 9

(4) 4M x 9

(4) 256K x 9

NONE

34MB

(4) 4M x 9

(4) 4M x 9

(4) 256K x 9

(4) 256K x 9

36MB

(4) 4M x 9

(4) 4M x 9

(4) 1M x 9

NONE

37MB

(4) 4M x 9

(4) 4M x 9

(4) 1M x 9

(4) 256K x 9

40MB

(4) 4M x 9

(4) 1M x 9

(4) 1M x 9

(4) 4M x 9

48MB

(4) 4M x 9

(4) 4M x 9

(4) 4M x 9

NONE

49MB

(4) 4M x 9

(4) 4M x 9

(4) 4M x 9

(4) 256K x 9

52MB

(4) 4M x 9

(4) 4M x 9

(4) 4M x 9

(4) 1M x 9

64MB

(4) 4M x 9

(4) 4M x 9

(4) 4M x 9

(4) 4M x 9