AST RESEARCH, INC.

BRAVO MS 486 (COBRA) (202612-XXX)

Processor

80486SX/80486DX/ODP486SX/80486DX2/80486DX4/Pentium Overdrive

Processor Speed

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

Chip Set

AST

Max. Onboard DRAM

128MB

Cache

64/256KB

BIOS

AMI

Dimensions

330mm x 218mm

I/O Options

Floppy drive interface, IDE interfaces (2), parallel port, PS/2 mouse port, serial ports (2), VGA feature connector, VGA port

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

VGA port

CN1

External battery

J26

Parallel port

CN2

Speaker

J27

Serial port 2

CN3

Chassis fan power

J28

Serial port 1

CN4

Front panel connector

J29

PS/2 mouse port

CN5

Chassis fan power

J32

VGA feature connector

J19

IDE interface LED

J40

IDE interface 2

J22

Video memory upgrade slot

SL1

IDE interface 1

J23

Riser Card

SL2

Floppy drive interface

J24

   

USER CONFIGURABLE SETTINGS

Function

Jumper/Switch

Position

»

Cache type select write back

E1

Open

 

Cache type select write through

E1

Closed

»

Factory configured - do not alter

E6

pins 1 & 2 closed

»

CMOS memory normal

E8

Open

 

CMOS memory clear

E8

Closed

»

Video memory enabled

E800

Closed

 

Video memory disabled

E800

Open

»

Flash BIOS write protect enabled

SW1/1

On

 

Flash BIOS write protect disabled

SW1/1

Off

»

Password enabled

SW1/2

On

 

Password disabled

SW1/2

Off

»

Monitor type select color

SW1/3

On

 

Monitor type select monochrome

SW1/3

Off

»

System setup enabled

SW1/4

Off

 

system setup disabled

SW1/4

On

»

On board video enabled

SW1/5

On

 

On board video disabled

SW1/5

Off

»

Factory configured - do not alter

SW1/6

On

»

Factory configured - do not alter

SW1/7

On

»

Factory configured - do not alter

SW1/8

On

DRAM CONFIGURATION

Size

Bank 0

Bank 1

Bank 2

Bank 3

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

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

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

49MB

(1) 4M x 36

(1) 4M x 36

(1) 4M x 36

(1) 256K x 36

64MB

(1) 4M x 36

(1) 4M x 36

(1) 4M x 36

(1) 4M x 36

64MB

(1) 8M x 36

(1) 8M x 36

NONE

NONE

65MB

(1) 8M x 36

(1) 8M x 36

(1) 256K x 36

NONE

66MB

(1) 8M x 36

(1) 8M x 36

(1) 256K x 36

(1) 256K x 36

DRAM CONFIGURATION (CON’T)

Size

Bank 0

Bank 1

Bank 2

Bank 3

68MB

(1) 8M x 36

(1) 8M x 36

(1) 1M x 36

NONE

72MB

(1) 8M x 36

(1) 8M x 36

(1) 1M x 36

(1) 1M x 36

96MB

(1) 8M x 36

(1) 8M x 36

(1) 8M x 36

NONE

128MB

(1) 8M x 36

(1) 8M x 36

(1) 8M x 36

(1) 8M x 36

CACHE CONFIGURATION

Size

Bank 0

Bank 1

TAG

64KB

(4) 8K x 8

(4) 8K x 8

(1) 8K x 8

256KB

(4) 32K x 8

(4) 32K x 8

(1) 32K x 8

CACHE JUMPER CONFIGURATION

Size

E5

64KB

Open

256KB

Closed

CPU TYPE CONFIGURATION

Type

E1

E2

E3

E4

80486SX (PQFP)

Open

pins 2 & 3 closed

pins 1 & 2 closed

Open

ODP486SX

Open

pins 2 & 3 closed

pins 1 & 2 closed

Open

80486DX (write back)

Open

pins 1 & 2 closed

pins 2 & 3 closed

Open

80486DX/DX2

Open

pins 1 & 2 closed

pins 1 & 2 closed

Open

80486DX4

Open

pins 1 & 2 closed

pins 1 & 2 closed

Open

Pentium Overdrive

Open

pins 2 & 3 closed

pins 2 & 3 closed

Open

CPU SPEED CONFIGURATION

Speed

E7

E9

25MHz

pins 1 & 2 closed

Closed

33MHz

pins 2 & 3 closed

Open

50iMHz

pins 1 & 2 closed

Closed

66iMHz

pins 2 & 3 closed

Open