TEXAS MICROSYSTEMS, INC.

D486 (REL. 2)

Processor

80486DX/80486DX2/80486DX4

Processor Speed

33/50/66(internal)/100(internal)MHz

Chip Set

Unidentified

Video Chip Set

None

Maximum Onboard Memory

128MB

Maximum Video Memory

None

Cache

64/128/256KB

BIOS

Unidentified

Dimensions

Unidentified

I/O Options

Floppy drive interface, IDE interface, parallel port, serial ports (2)

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

IDE interface

CN1

Parallel port

CN5

Floppy drive interface

CN2

AT keyboard connector

CN6

Serial port 2

CN3

External battery

JP9

Serial port 1

CN4

IDE interface LED

JP10

USER CONFIGURABLE SETTINGS

Function

Label

Position

»

Battery type select internal

JP9

Pins 1 & 2 closed

 

Battery type select external

JP9

Closed

»

Watchdog timer disabled

JP11

Pins 2 & 3 closed

 

Watchdog timer enabled

JP11

Pins 1 & 2 closed

»

Monitor type select color

SW1/1

On

 

Monitor type select monochrome

SW1/1

Off

»

Flash BIOS enabled

SW1/2

Off

 

Flash BIOS disabled

SW1/2

On

»

CMOS memory normal operation

SW1/3

Off

 

CMOS memory clear

SW1/3

On

»

I/O address select 270H

SW1/4

Off

 

I/O address select 370H

SW1/4

On

DRAM CONFIGURATION

Size

Bank 0

Bank 1

8MB

(2) 1M x 36

None

16MB

(2) 1M x 36

(2) 1M x 36

24MB

(2) 2M x 36

(2) 1M x 36

32MB

(2) 4M x 36

None

40MB

(2) 4M x 36

(2) 1M x 36

48MB

(2) 4M x 36

(2) 2M x 36

64MB

(2) 8M x 36

None

64MB

(2) 4M x 36

(2) 4M x 36

96MB

(2) 8M x 36

(2) 4M x 36

128MB

(2) 8M x 36

(2) 8M x 36

Note: Board also accepts x 32 SIMMs.

CACHE CONFIGURATION

Note: The chip sizes and location of the cache is unidentified.

CACHE JUMPER CONFIGURATION

Size

JP5

JP6

JP7

JP8

64KB

Pins 1 & 2 closed

Pins 1 & 2 closed

Pins 1 & 2 closed

Open

128KB

Pins 2 & 3 closed

Pins 1 & 2 closed

Pins 2 & 3 closed

Pins 1 & 2 closed

256KB

Pins 2 & 3 closed

Pins 2 & 3 closed

Pins 1 & 2 closed

Pins 2 & 3 closed

CPU SPEED SELECTION

Speed

JP4

33MHz

Pins 1 & 2 closed

CPU TYPE SELECTION

Type

JP1

JP2

JP3

JP14

80486DX

Pins 1 & 2 closed

Pins 2 & 3 closed

Pins 1 & 2 closed

Pins 2 & 3 closed

80486DX2

Pins 1 & 2 closed

Pins 2 & 3 closed

Pins 1 & 2 closed

Pins 2 & 3 closed

80486DX4

Pins 1 & 2 closed

Pins 2 & 3 closed

Pins 1 & 2 closed

Pins 1 & 2 closed

CPU MULTIPLIER SELECTION (80486DX4 ONLY)

Multiplier

JP13

2x

Pins 2 & 3 closed

3x

Pins 1 & 2 closed

WATCHDOG TIMER SELECTION

Timer

JP12

»

150ms

Pins 2 & 3 closed

 

600ms

Open

 

1.2 seconds

Pins 1 & 2 closed