ABIT COMPUTER CORPORATION
AS420/AS425/AS433/AS455
Processor | 80486SX/80486DX |
Processor Speed | 20/25/33/40MHz |
Chip Set | SIS |
Max. Onboard DRAM | 32MB |
Cache | 32/64/128/256/512/1024KB |
BIOS | AMI |
Dimensions | 330mm x 214mm |
I/O Options | None |
NPU Options | 4167 |
CONNECTIONS | |||
Purpose | Location | Purpose | Location |
Turbo LED | D6 | Reset | JP20 |
External battery | JP15 | Speaker | JP21 |
Turbo switch | JP19 | Power LED & keylock | JP22 |
USER CONFIGURABLE SETTINGS | |||
Function | Jumper | Position | |
» | Factory configured - do not alter | JP2 | Open |
» | Monitor type select monochrome | JP4 | Open |
Monitor type select color | JP4 | Closed | |
» | CMOS memory normal operation | JP5 | pins 1 & 2 closed |
CMOS memory clear | JP5 | pins 2 & 3 closed | |
» | Factory configured - do not alter | JP6 | pins 1 & 2 closed |
» | Factory configured - do not alter | JP8 | pins 1 & 2 closed |
» | Factory configured - do not alter | JP14 | pins 1 & 2 closed |
» | Factory configured - do not alter | JP17 | pins 1 & 2 closed |
DRAM CONFIGURATION | ||
Size | Bank 0 | Bank 1 |
1MB | (4) 256K x 9 | NONE |
2MB | (4) 256K x 9 | (4) 256K x 9 |
4MB | (4) 1M x 9 | NONE |
8MB | (4) 1M x 9 | (4) 1M x 9 |
16MB | (4) 4M x 9 | NONE |
32MB | (4) 4M x 9 | (4) 4M x 9 |
CACHE CONFIGURATION | ||||
Size | Bank 0 | Bank 1 | TAG (U28 & U29) | TAG (U30) |
32KB | (4) 8K x 8 | NONE | (2) 16K x 4 | NONE |
32KB | (4) 8K x 8 | NONE | NONE | (1) 8K x 8 |
64KB | (4) 8K x 8 | (4) 8K x 8 | (2) 16K x 4 | NONE |
64KB | (4) 8K x 8 | (4) 8K x 8 | NONE | (1) 8K x 8 |
128KB | (4) 32K x 8 | NONE | (2) 64K x 4 | NONE |
128KB | (4) 32K x 8 | NONE | NONE | (1) 32K x 8 |
256KB | (4) 32K x 8 | (4) 32K x 8 | (2) 16K x 4 | NONE |
256KB | (4) 32K x 8 | (4) 32K x 8 | NONE | (1) 32K x 8 |
512KB | (4) 128K x 8 | NONE | NONE | (1) 128K x 8 |
1024KB | (4) 128K x 8 | (4) 128K x 8 | (2) 64K x 4 | NONE |
1024KB | (4) 128K x 8 | (4) 128K x 8 | NONE | (1) 128K x 8 |
CACHE JUMPER CONFIGURATION | ||||||
Size | JP28 | JP30 | JP31 | JPX1/JPX2 | JPX3 | JPX4 |
32KB | 2 & 3 | Open | Closed | 1 - 8 | Open | 1 - 16 |
64KB | 1 & 2 | Closed | Open | 1 - 8 | 1 - 16 | Open |
128KB | 1 & 2 | Closed | Closed | 3 - 10 | 1 - 16 | Open |
256KB | 1 & 2 | Closed | Open | 5 - 12 | 1 - 16 | Open |
512KB | 1 & 2 | Closed | Open | 7 - 14 | Open | 1 - 16 |
1024KB | 1 & 2 | Closed | Closed | 9 - 18 | 1 - 16 | Open |
Note: Jumpers JPX1-JPX4 are closed using one or two 8-pin terminating resistors. |
CPU TYPE CONFIGURATION | ||
Type | JP25 | JPX5 |
80486SX | Closed | Open |
80486DX | Open | Closed |