UNIDENTIFIED
STC-SIS486C-DX/SX
Processor | 80486SX/80487SX/80486DX |
Processor Speed | 20/25/33/50MHz |
Chip Set | SIS |
Max. onboard DRAM | 32MB |
Cache | 32/64/128/256KB |
BIOS | AMI |
Dimensions | 218mm x 218mm |
I/O Options | None |
NPU Options | None |
CONNECTIONS | |||
Purpose | Location | Purpose | Location |
External battery | J1 | Turbo LED | J6 |
Power LED & keylock | J3 | Turbo switch | J7 |
Speaker | J4 | Reset switch | J8 |
Unknown | J5 |
USER CONFIGURABLE SETTINGS | |||
Function | Jumper | Position | |
» | CMOS memory normal operation (internal battery) | J1 | pins 2 & 3 closed |
CMOS memory normal operation (external battery) | J1 | pins 1 & 4 closed | |
CMOS memory clear | J1 | Open | |
» | Monitor type select color | J2 | Closed |
Monitor type select monochrome | J2 | Open | |
» | CPU speed select iOSC/1 | J9 | pins 1 & 2 closed |
CPU speed select iOSC/2 | J9 | pins 2 & 3 closed | |
» | Turbo switch enabled | J10 | Closed |
Turbo switch disabled | J10 | Open |
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 |
20MB | (4) 1M x 9 | (4) 4M x 9 |
32MB | (4) 4M x 9 | (4) 4M x 9 |
CACHE CONFIGURATION | ||||
Size | Bank 0 (U26 - 29) | Bank 1 (U22 - U25) | Tag | Dirty Bit |
32KB | (4) 8K x 8 | NONE | 8K x 8 | 16K x 4 |
64KB | (4) 8K x 8 | (4) 8K x 8 | 8K x 8 | 16K x 4 |
128KB | (4) 32K x 8 | NONE | 32K x 8 | 16K x 4 |
256KB | (4) 32K x 8 | (4) 32K x 8 | 32K x 8 | 16K x 4 |
CACHE JUMPER CONFIGURATION | |||||||||
Size | J11 | J12 | J13 | J14 | J15 | J16 | J17 | J18 | J19 |
32KB | 1 & 2 | Open | 1 & 2 | 1 & 2 | 1 & 2 | 1 & 2 | 1 & 2 | 1 & 2 | 1 & 2 |
64KB | 2 & 3 | Open | 1 & 2 | 2 & 3 | 1 & 2 | 1 & 2 | 2 & 3 | 1 & 2 | 1 & 2 |
128KB | 1 & 2 | 1 & 2 | 2 & 3 | 2 & 3 | 2 & 3 | 1 & 2 | 2 & 3 | 2 & 3 | 1 & 2 |
256KB | 2 & 3 | 2 & 3 | 2 & 3 | 2 & 3 | 2 & 3 | 2 & 3 | 2 & 3 | 2 & 3 | 2 & 3 |
Note:Pins designated should be in the closed position. |
CPU TYPE CONFIGURATION | |||
Type | J20 | J21 | J22 |
80486SX | Closed | pins 1 & 2 closed | pins 1 & 2 closed |
80487SX | Closed | pins 1 & 2 closed | pins 2 & 3 closed |
80486DX | Open | pins 2 & 3 closed | Open |