UNIDENTIFIED
486SX/DX/DX2-MAINBOARD
Processor | 80486SX/80486DX/80486DX2 |
Processor Speed | 20/25/33/50(internal)/50/66(internal)MHz |
Chip Set | UNI |
Video Chip Set | None |
Maximum Onboard Memory | 32MB |
Maximum Video Memory | None |
Cache | 64/128/256KB |
BIOS | AMI |
Dimensions | 260mm x 220mm |
I/O Options | 32-bit VESA local bus slots (3) |
NPU Options | None |
CONNECTIONS | |||
Purpose | Location | Purpose | Location |
Turbo switch | H1 | Reset switch | H5 |
Turbo LED | H2 | External battery | J1 |
Power LED & keylock | H3 | 32-bit VESA local bus slots | SL1 - SL3 |
Speaker | H4 |
USER CONFIGURABLE SETTINGS | |||
Function | Label | Position | |
» | Turbo enabled | H1 | Closed |
Turbo enabled through keyboard (CTRL, ALT, +) | H1 | Open | |
Turbo disabled through keyboard (CTRL, ALT, -) | H1 | Open | |
» | CMOS memory normal operation | J1 | Pins 2 & 3 closed |
CMOS memory clear | J1 | Pins 3 & 4 closed | |
Battery type select external | J1 | Closed | |
» | Monitor type select color | J3 | Closed |
Monitor type select monochrome | J3 | Open | |
» | VL-BUS clock normal operation | JP43 | Pins 2 & 3 closed |
VL-BUS clock adjusted | JP43 | 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 |
5MB | (4) 256K x 9 | (4) 1M x 9 |
8MB | (4) 1M x 9 | (4) 1M x 9 |
16MB | (4) 4M x 9 | None |
20MB | (4) 1M x 9 | (4) 4M x 9 |
20MB | (4) 4M x 9 | (4) 1M x 9 |
32MB | (4) 4M x 9 | (4) 4M x 9 |
CACHE CONFIGURATION | |||
Size | Bank 0 | Bank 1 | TAG |
64KB | (4) 8K x 8 | (4) 8K x 8 | (1) 8K x 8 |
128KB | (4) 32K x 8 | None | (1) 8K x 8 |
256KB | (4) 32K x 8 | (4) 32K x 8 | (1) 32K x 8 |
CACHE JUMPER CONFIGURATION | ||||
Size | JP6 | JP7 | JP8 | JP9 |
64KB | Open | Closed | Open | Pins 1 & 2 closed |
128KB | Open | Closed | Closed | Pins 1 & 2, 3 & 4 closed |
256KB | Closed | Closed | Closed | Pins 1 & 2, 4 & 5 closed |
CPU SPEED SELECTION | |||
Speed | JP29 | JP30 | JP31 |
20MHz | Open | Closed | Open |
25MHz | Closed | Open | Closed |
33MHz | Closed | Closed | Open |
50iMHz | Closed | Open | Closed |
50MHz | Open | Closed | Open |
66iMHz | Closed | Closed | Open |
CPU TYPE SELECTION | |
Type | JP4 |
80486SX | Pins 5 & 6 closed |
80486DX | Pins 1 & 2, 4 & 5, 6 & 7 closed |
80486DX2 | Pins 1 & 2, 4 & 5, 6 & 7 closed |
VL BUS WAIT STATE SELECTION | ||
Setting | JP20 | |
0 | Open | |
» | 1 | Closed |
VL BUS SPEED SELECTION | ||
Speed | JP19 | |
<= 33MHz | Open | |
» | >33 MHz | Closed |