ABIT COMPUTER CORPORATION
AT420/AT425/AT433/AT450
|
Processor |
80486SX/80486DX |
|
Processor Speed |
20/25/33/50MHz |
|
Chip Set |
SIS |
|
Max. Onboard DRAM |
32MB |
|
Cache |
32/64/128/256/512/1024KB |
|
BIOS |
AMI |
|
Dimensions |
330mm x 218mm |
|
I/O Options |
None |
|
NPU Options |
4167 |
|
CONNECTIONS | |||
|
Purpose |
Location |
Purpose |
Location |
|
Speaker |
CN1 |
Turbo switch |
JP1 |
|
Power LED & keylock |
CN2 |
Turbo LED |
JP2 |
|
External battery |
CN3 |
Reset switch |
SW1 |
|
USER CONFIGURABLE SETTINGS | |||
|
Function |
Jumper |
Position | |
|
CMOS memory normal operation |
JP5 |
pins 1 & 2 closed | |
|
CMOS memory clear |
JP5 |
pins 2 & 3 closed | |
|
Monitor type select monochrome |
JP7 |
Open | |
|
Monitor type select color |
JP7 |
Closed | |
|
Factory configured - do not alter |
JP8 |
Open | |
|
Note:Jumper JPX3 is closed using an 8-pin terminating resistor. | |||
|
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 |
Location |
|
32KB |
(4) 8K x 8 |
NONE |
(1) 8K x 8 |
T-1 |
|
32KB |
(4) 8K x 8 |
(4) 8K x 8 |
(2) 16K x 4 |
T-2 |
|
64KB |
(4) 8K x 8 |
(4) 8K x 8 |
(1) 8K x 8 |
T-1 |
|
64KB |
(4) 8K x 8 |
(4) 8K x 8 |
(2) 16K x 4 |
T-2 |
|
128KB |
(4) 32K x 8 |
NONE |
(1) 8K x 8 |
T-1 |
|
128KB |
(4) 32K x 8 |
NONE |
(2) 16K x 4 |
T-2 |
|
256KB |
(4) 32K x 8 |
(4) 32K x 8 |
(2) 16K x 4 |
T-2 |
|
512KB |
(4) 128K x 8 |
NONE |
(1) 32K x 8 |
T-1 |
|
512KB |
(4) 128K x 8 |
NONE |
(2) 64K x 4 |
T-2 |
|
1024KB |
(4) 128K x 8 |
(4) 128K x 8 |
(1) 128K x 8 |
T-1 |
|
1024KB |
(4) 128K x 8 |
(4) 128K x 8 |
(2) 64K x 4 |
T-2 |
|
CACHE JUMPER CONFIGURATION | ||||
|
Size |
JP3 |
JP4 |
JPX4 |
JPX5 |
|
32KB |
Open |
Open |
pins 1 - 8 closed |
pins 1 - 8 closed |
|
64KB |
Open |
Open |
pins 9 - 16 closed |
pins 3 - 10 closed |
|
128KB |
Open |
Closed |
pins 1 - 8 closed |
pins 5 - 12 closed |
|
256KB |
Open |
Closed |
pins 9 - 16 closed |
pins 7 - 14 closed |
|
512KB |
Open |
Closed |
pins 1 - 8 closed |
pins 9 - 16 closed |
|
1024KB |
Closed |
Closed |
pins 9 - 16 closed |
pins 9 - 16 closed |
|
Note:Jumpers JPX4 & JPX5 are closed using 8-pin terminating resistors. | ||||
|
CACHE JUMPER CONFIGURATION | ||
|
Type |
JP6 |
JPX3 |
|
80486SX |
Closed |
Open |
|
80486DX |
Open |
Closed |