...because we can't all be on the bleeding edge...





Precision 486SX/25, 486DX/33, 486DX2/50

DELL COMPUTER CORPORATION

Precision 486SX/25, 486DX/33, 486DX2/50

Processor

80486SX/80487SX/80486DX/80486DX2

Processor Speed

25/33/50MHz

Chip Set

OPTI

Max. Onboard DRAM

64MB

Cache

64/256KB

BIOS

AMI

Dimensions

330mm x 218mm

I/O Options

Bus mouse port, floppy interface, IDE interface, parallel port, proprietary expansion module, serial ports (2), VGA port

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

Internal battery holder

BAT

Serial port 1

J10

Proprietary expansion module

EXP

IDE interface LED

J23

Bus mouse

J1

Reset switch

J24

IDE interface

J5

Speaker

J25

Floppy drive interface

J6

Power LED & keylock

J26

Parallel port

J8

VGA port

J27

Serial port 2

J9

   

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

Monitor type select color or monochrome VGA

W1

pins 1 & 2 closed

 

Monitor type select monochrome

W1

pins 2 & 3 closed

CMOS memory normal operation

W2

pins 1 & 2 closed

 

CMOS memory clear

W2

pins 2 & 3 closed

CPU clock source select SYSCLK/1

W3

pins 1 & 2 closed

 

CPU clock source select SYSCLK/2

W3

pins 2 & 3 closed

VGA port enabled

W10

pins 1 & 2 closed

 

VGA port disabled

W10

pins 2 & 3 closed

DRAM CONFIGURATION

Size

Bank 0

Bank 1

Bank 2

Bank 3

1MB

(1) 256K x 36

NONE

NONE

NONE

2MB

(1) 256K x 36

(1) 256K x 36

NONE

NONE

3MB

(1) 256K x 36

(1) 256K x 36

(1) 256K x 36

NONE

4MB

(1) 256K x 36

(1) 256K x 36

(1) 256K x 36

(1) 256K x 36

4MB

(1) 1M x 36

NONE

NONE

NONE

5MB

(1) 1M x 36

(1) 256K x 36

NONE

NONE

6MB

(1) 1M x 36

(1) 256K x 36

(1) 256K x 36

NONE

8MB

(1) 1M x 36

(1) 1M x 36

NONE

NONE

9MB

(1) 1M x 36

(1) 1M x 36

(1) 256K x 36

NONE

10MB

(1) 1M x 36

(1) 1M x 36

(1) 256K x 36

(1) 256K x 36

12MB

(1) 1M x 36

(1) 1M x 36

(1) 1M x 36

NONE

16MB

(1) 1M x 36

(1) 1M x 36

(1) 1M x 36

(1) 1M x 36

16MB

(1) 4M x 36

NONE

NONE

NONE

17MB

(1) 4M x 36

(1) 256K x 36

NONE

NONE

18MB

(1) 4M x 36

(1) 256K x 36

(1) 256K x 36

NONE

20MB

(1) 4M x 36

(1) 1M x 36

NONE

NONE

24MB

(1) 4M x 36

(1) 1M x 36

(1) 1M x 36

NONE

32MB

(1) 4M x 36

(1) 4M x 36

NONE

NONE

33MB

(1) 4M x 36

(1) 4M x 36

(1) 256K x 36

NONE

34MB

(1) 4M x 36

(1) 4M x 36

(1) 256K x 36

(1) 256K x 36

36MB

(1) 4M x 36

(1) 4M x 36

(1) 1M x 36

NONE

40MB

(1) 4M x 36

(1) 4M x 36

(1) 1M x 36

(1) 1M x 36

48MB

(1) 4M x 36

(1) 4M x 36

(1) 4M x 36

NONE

64MB

(1) 4M x 36

(1) 4M x 36

(1) 4M x 36

(1) 4M x 36

CACHE CONFIGURATION

Size

Bank 0

64KB

(8) 8K x 8

256KB

(8) 32K x 8

CACHE JUMPER CONFIGURATION

Size

W4

W5

W9

64KB

pins 2 & 3 closed

pins 2 & 3 closed

pins 2 & 3 closed

256KB

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

CPU TYPE CONFIGURATION

Type

W6

W7

W8

80486SX

pins 2 & 3 closed

pins 2 & 3 closed

Open

80487SX

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

80486DX

pins 1 & 2 closed

pins 1 & 2 closed

pins 2 & 3 closed

VGA REFRESH CONFIGURATION (800 X 600 RESOLUTION)

Refresh Rate

SW1/1

SW1/2

 

56Hz

Off

Off

 

56Hz

On

On

60Hz

Off

On

 

72Hz

On

Off

VGA REFRESH CONFIGURATION (1024 X 768 RESOLUTION)

Refresh Rate

SW1/3

SW1/4

Interlaced

Off

Off

 

60Hz

Off

On

 

70Hz

On

Off

 

72Hz

On

On

VGA REFRESH CONFIGURATION

Refresh Rate

SW1/5

31.5Hz horizontal, 60/70Hz vertical

Off

 

40Hz horizontal, 75/80Hz vertical (see note)

On

 

Note :Use 75Hz for video modes 0 through 10h and 13h. Use 80Hz for video modes 11h and 12h.

VRAM CONFIGURATION

Size

Bank 0

512KB

NONE

 

1MB

(4) 44256 ZIPPs

VRAM SWITCH CONFIGURATION

Size

SW1/6

512KB

On

 

1MB

Off