ABIT COMPUTER CORPORATION
AH4/AH4T (REV. 1.2)
Processor | 80486SX/SL80486SX/CX486M7/80486DX/SL80486DX/CX486DX2/AM486DX2/80486DX2/SL80486DX2/AM486DX4/80486DX4 |
Processor Speed | 20/25/33/40/50(internal)/66(internal)/75(internal)/100(internal)MHz |
Chip Set | Unidentifed |
Max. Onboard DRAM | 128MB |
Cache | 128/256/512KB |
BIOS | Award |
Dimensions | 330mm x 218mm |
I/O Options | 32-bit VESA local bus slots (3), green PC connector |
NPU Options | None |
CONNECTIONS | |||
Purpose | Location | Purpose | Location |
External battery | J1 | Reset switch | JW3 |
Green PC connector | JP45 pins 7 - 8 | Turbo LED | JW4 |
Power LED & keylock | JW1 | Turbo switch | JW5 |
Speaker | JW2 | 32-bit VESA local bus slots | SL1 - SL3 |
USER CONFIGURABLE SETTINGS | |||
Function | Jumper | Position | |
» | CMOS memory normal operation | JP16 | pins 1 & 2 closed |
| CMOS memory clear | JP16 | pins 2 & 3 closed |
» | Factory configured - do not alter | JP17 | N/A |
» | Factory configured - do not alter | JP19 | pins 1 & 2 closed |
» | Factory configured - do not alter | JP23 | pins 1 & 2 closed |
» | Factory configured - do not alter | JP26 | Open |
» | Factory configured - do not alter | JP30 | N/A |
» | Factory configured - do not alter | JP31 | N/A |
» | Factory configured - do not alter | JP42 | Closed |
Note: The locations of JP19, JP23 & JP42 are unidentified. |
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 |
2MB | (1) 512K x 36 | NONE | NONE | NONE |
4MB | (1) 512K x 36 | (1) 512K x 36 | NONE | NONE |
4MB | (1) 1M x 36 | NONE | NONE | NONE |
4MB | (1) 256K x 36 | (1) 256K x 36 | (1) 512K x 36 | NONE |
5MB | (1) 256K x 36 | (1) 1M x 36 | NONE | NONE |
6MB | (1) 256K x 36 | (1) 256K x 36 | (1) 1M x 36 | NONE |
6MB | (1) 512K x 36 | (1) 1M x 36 | NONE | NONE |
8MB | (1) 256K x 36 | (1) 256K x 36 | (1) 512K x 36 | (1) 1M x 36 |
8MB | (1) 512K x 36 | (1) 512K x 36 | (1) 1M x 36 | NONE |
8MB | (1) 1M x 36 | (1) 1M x 36 | NONE | NONE |
8MB | (1) 2M x 36 | NONE | NONE | NONE |
10MB | (1) 256K x 36 | (1) 256K x 36 | (1) 1M x 36 | (1) 1M x 36 |
12MB | (1) 512K x 36 | (1) 512K x 36 | (1) 1M x 36 | (1) 1M x 36 |
12MB | (1) 1M x 36 | (1) 1M x 36 | (1) 1M x 36 | NONE |
16MB | (1) 2M x 36 | (1) 2M x 36 | NONE | 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) 256K x 36 | (1) 4M x 36 | NONE | NONE |
18MB | (1) 256K x 36 | (1) 256K x 36 | (1) 4M x 36 | NONE |
20MB | (1) 512K x 36 | (1) 512K x 36 | (1) 4M x 36 | NONE |
20MB | (1) 1M x 36 | (1) 4M x 36 | NONE | NONE |
24MB | (1) 2M x 36 | (1) 2M x 36 | (1) 2M x 36 | NONE |
24MB | (1) 512K x 36 | (1) 512K x 36 | (1) 1M x 36 | (1) 4M x 36 |
24MB | (1) 1M x 36 | (1) 1M x 36 | (1) 4M x 36 | NONE |
32MB | (1) 2M x 36 | (1) 2M x 36 | (1) 2M x 36 | (1) 2M x 36 |
32MB | (1) 4M x 36 | (1) 4M x 36 | NONE | NONE |
32MB | (1) 8M x 36 | NONE | NONE | NONE |
36MB | (1) 512K x 36 | (1) 512K x 36 | (1) 4M x 36 | (1) 4M x 36 |
36MB | (1) 1M x 36 | (1) 4M x 36 | (1) 4M x 36 | NONE |
DRAM CONFIGURATION (CON’T) | ||||
Size | Bank 0 | Bank 1 | Bank 2 | Bank 3 |
36MB | (1) 1M x 36 | (1) 8M x 36 | NONE | NONE |
40MB | (1) 1M x 36 | (1) 1M x 36 | (1) 4M x 36 | (1) 4M x 36 |
40MB | (1) 1M x 36 | (1) 1M x 36 | (1) 8M x 36 | NONE |
48MB | (1) 4M x 36 | (1) 4M x 36 | (1) 4M x 36 | NONE |
48MB | (1) 4M x 36 | (1) 8M x 36 | NONE | NONE |
64MB | (1) 4M x 36 | (1) 4M x 36 | (1) 4M x 36 | (1) 4M x 36 |
64MB | (1) 16M x 36 | NONE | NONE | NONE |
64MB | (1) 4M x 36 | (1) 4M x 36 | (1) 8M x 36 | NONE |
64MB | (1) 8M x 36 | (1) 8M x 36 | NONE | NONE |
65MB | (1) 256K x 36 | (1) 16M x 36 | NONE | NONE |
68MB | (1) 1M x 36 | (1) 16M x 36 | NONE | NONE |
68MB | (1) 1M x 36 | (1) 8M x 36 | (1) 8M x 36 | NONE |
72MB | (1) 1M x 36 | (1) 1M x 36 | (1) 16M x 36 | NONE |
72MB | (1) 1M x 36 | (1) 1M x 36 | (1) 8M x 36 | (1) 8M x 36 |
80MB | (1) 4M x 36 | (1) 16M x 36 | NONE | NONE |
80MB | (1) 4M x 36 | (1) 8M x 36 | (1) 8M x 36 | NONE |
96MB | (1) 4M x 36 | (1) 4M x 36 | (1) 16M x 36 | NONE |
96MB | (1) 4M x 36 | (1) 4M x 36 | (1) 8M x 36 | (1) 8M x 36 |
96MB | (1) 8M x 36 | (1) 8M x 36 | (1) 8M x 36 | NONE |
128MB | (1) 16M x 36 | (1) 16M x 36 | NONE | 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 |
128KB | (4) 32K x 8 | NONE | (1) 8K x 8 |
256KB | (4) 32K x 8 | (4) 32K x 8 | (1) 32K x 8 |
256KB | (4) 64K x 8 | NONE | (1) 32K x 8 |
512KB | (4) 64K x 8 | (4) 64K x 8 | (1) 32K x 8 |
512KB | (4) 128K x 8 | NONE | (1) 32K x 8 |
CACHE JUMPER CONFIGURATION | |||||
Size | JP1 | JP2 | JP4 | JP40 | JP41 |
128KB | 1 & 2 | 1 & 2 | 1 & 2 | 1 & 2 | 1 & 2 |
256KB | 2 & 3 | 2 & 3 | 1 & 2 | 2 & 3 | 2 & 3 |
256KB | 1 & 2 | 2 & 3 | 1 & 2 | 1 & 2 | 1 & 2 |
512KB | 2 & 3 | 2 & 3 | 2 & 3 | 2 & 3 | 2 & 3 |
512KB | 1 & 2 | 2 & 3 | 2 & 3 | 1 & 2 | 1 & 2 |
Note: Pins designated should be in the closed position. |
CPU TYPE CONFIGURATION | |||||
Type | JP8 | JP9 | JP11 | JP12 | JP14 |
80486SX | 2 & 3 | Open | Open | 3 & 4 | 2 & 3 |
SL80486SX | 2 & 3 | Open | Open | 3 & 4 | 2 & 3 |
CX486M7 | 1 & 2 | Closed | 2 & 3 | 2 & 3 | 1 & 2, 3 & 4 |
80486DX | 1 & 2 | Closed | 2 & 3 | 3 & 4 | 2 & 3 |
SL80486DX | 1 & 2 | Closed | 2 & 3 | 3 & 4 | 2 & 3 |
CX486DX2 | 1 & 2 | Closed | 2 & 3 | 2 & 3 | 1 & 2, 3 & 4 |
AM486DX2 | 1 & 2 | Closed | 2 & 3 | 3 & 4 | 2 & 3 |
80486DX2 | 1 & 2 | Closed | 2 & 3 | 3 & 4 | 2 & 3 |
SL80486DX2 | 1 & 2 | Closed | 2 & 3 | 3 & 4 | 2 & 3 |
AM486DX4 | 1 & 2 | Closed | 2 & 3 | 3 & 4 | 2 & 3 |
80486DX4 | 1 & 2 | Closed | 2 & 3 | 3 & 4 | 2 & 3 |
Note: Pins designated should be in the closed position. SL80486DX/DX2 is only available on the AH4T mainboard |
CPU TYPE CONFIGURATION | |||||
Type | JP15 | JP21 | JP22 | JP24 | JP25 |
80486SX | 4 & 5 | 2 & 3 | 1 & 2 | Open | Open |
SL80486SX | 4 & 5 | 2 & 3 | 1 & 2 | Open | Open |
CX486M7 | 2 & 3 | 1 & 2 | 2 & 3 | 2 & 3 | 2 & 3 |
80486DX | 4 & 5 | 2 & 3 | 1 & 2 | Open | Open |
SL80486DX | 4 & 5 | 2 & 3 | 1 & 2 | Open | Open |
CX486DX2 | 2 & 3 | 1 & 2 | 2 & 3 | 2 & 3 | 2 & 3 |
AM486DX2 | 4 & 5 | 2 & 3 | 1 & 2 | Open | Open |
80486DX2 | 4 & 5 | 2 & 3 | 1 & 2 | Open | Open |
SL80486DX2 | 4 & 5 | 2 & 3 | 1 & 2 | Open | Open |
AM486DX4 | 4 & 5 | 2 & 3 | 1 & 2 | Open | Open |
80486DX4 | 4 & 5 | 2 & 3 | 1 & 2 | Open | Open |
Note: Pins designated should be in the closed position. SL80486DX/DX2 is only available on the AH4T mainboard |
CPU TYPE CONFIGURATION | ||||||
Type | JP32 | JP46 | JP48 | JP49 | JP50 | JP62 |
80486SX | 1 & 2 | 2 & 3 | 2 & 3 | Open | 2 & 3 | Open |
SL80486SX | 1 & 2 | 2 & 3 | 2 & 3 | Open | 2 & 3 | Open |
CX486M7 | 1 & 2 | 1 & 2 | 2 & 3 | Open | 2 & 3 | Open |
80486DX | 1 & 2 | 2 & 3 | 2 & 3 | Open | 2 & 3 | Open |
SL80486DX | 1 & 2 | 2 & 3 | 2 & 3 | Open | 2 & 3 | Open |
CX486DX2 | 1 & 2 | 1 & 2 | 1 & 2 | Open | 1 & 2 | Open |
AM486DX2 | 1 & 2 | 2 & 3 | 1 & 2 | Open | 1 & 2 | Open |
80486DX2 | 1 & 2 | 2 & 3 | 2 & 3 | Open | 2 & 3 | Open |
SL80486DX2 | 1 & 2 | 2 & 3 | 2 & 3 | Open | 2 & 3 | Open |
AM486DX4 | 1 & 2 | 2 & 3 | 1 & 2 | 1 & 2 | 1 & 2 | Closed |
80486DX4 | Open | 2 & 3 | 1 & 2 | 1 & 2 | 1 & 2 | Open |
Note: Pins designated should be in the closed position. SL80486DX/DX2 is only available on the AH4T mainboard |
CPU SPEED CONFIGURATION | |||
Speed | JP5 | JP6 | JP7 |
20MHz | Closed | Open | Closed |
25MHz | Closed | Closed | Open |
33MHz | Open | Closed | Closed |
40MHz | Closed | Open | Open |
50iMHz | Closed | Closed | Open |
66iMHz | Open | Closed | Closed |
75iMHz | Closed | Closed | Open |
100iMHz | Open | Closed | Closed |
CPU VOLTAGE CONFIGURATION | ||||
Voltage | JP53 | JP54 | JP55 | JP56 |
3.3v | Closed | Open | Open | Open |
3.45v | Open | Closed | Open | Open |
3.6v | Open | Open | Closed | Open |
4v | Open | Open | Open | Closed |
BUS SPEED CONFIGURATION | |
CPU speed | JP29 |
<= 33MHz | pins 1 & 2 closed |
> 33MHz | pins 2 & 3 closed |