COMPUTREND SYSTEMS, INC.
UMC-386 (MS-3131 Ver. 1.1)
Processor | 80386DX |
Processor Speed | 33/40MHz |
Chip Set | UMC |
Max. Onboard DRAM | 32MB |
SRAM Cache | 32/64/128/256KB |
BIOS | AMI |
Dimensions | 220mm x 220mm |
I/O Options | Auxiliary keyboard connector |
NPU Options | 80387 |

CONNECTIONS | |||
Purpose | Location | Purpose | Location |
External battery | J1 | Turbo switch | J2/15 - 17 |
Power LED & keylock | J2/1 - 5 | Turbo LED | J2/12 & 13 |
Speaker | J2/7 - 10 | Auxiliary keyboard | KB2 |
Reset switch | J2/19 & 20 | ||
USER CONFIGURABLE SETTINGS | |||
Function | Jumper | Position | |
| » | Monitor type select monochrome | JP1 | open |
Monitor type select color | JP1 | closed | |
| » | NPU disabled | JP3 JP9 | open open |
NPU endabled | JP3 JP9 | closed closed | |
| » | Battery select internal | J1 | pins 2 & 3 closed |
battery select external | J1 | connected | |
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 JUMPER CONFIGURATION | ||||||||
Size | JP4 | JP5 | JP6 | JP7 | JP8 | JP11 | JP12 | JP13 |
32KB | open | open | pins 2 & 3 | pins 1 & 2 | pins 1 & 2 | pins 2 & 3 | pins 1 & 2 | open |
64KB | open | open | pins 2 & 3 | pins 1 & 2 | pins 1 & 2 | pins 1 & 2 | pins 2 & 3 | closed |
128KB | closed | open | pins 1 & 2 | pins 2 & 3 | pins 1 & 2 | pins 1 & 2 | pins 2 & 3 | closed |
256KB | closed | closed | pins 2 & 3 | pins 2 & 3 | pins 2 & 3 | pins 1 & 2 | pins 2 & 3 | closed |
Note:Pins designated should be in the closed position. | ||||||||
CACHE CONFIGURATION | |||
Size | Cache SRAM | Location | TAG |
32KB | (4) 8K x 8 | Bank 0 | (1) 8K x 8 |
64KB | (8) 8K x 8 | Banks 0 & 1 | (1) 8K x 8 |
128KB | (4) 32K x 8 | Bank 0 | (1) 8K x 8 |
256KB | (8) 32K x 8 | Banks 0 & 1 | (1) 32K x 8 |