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 |