EVEREX SYSTEMS, INC.
SYSTEM 3900 (EV-1851)
| Processor | 80386DX | 
| Processor Speed | 25/33MHz | 
| Chip Set | C & T | 
| Max. Onboard DRAM | 8MB | 
| Cache | 64KB | 
| BIOS | AMI | 
| Dimensions | 355mm x 304mm | 
| I/O Options | 32-bit external memory card slot | 
| NPU Options | 80387/3167 | 
 
| CONNECTIONS | |||
| Purpose | Location | Purpose | Location | 
| Speaker | J17 | Keylock | J18 pin 9 | 
| Power LED | J18 pin 1 | External battery connector | J22 | 
| Turbo LED | J18 pin 2 | Speaker enable/disable switch | J23 | 
| Reset switch | J18 pin 6 | 32-bit external memory card | S1 | 
| USER CONFIGURABLE SETTINGS | |||
| Function | Jumper | Position | |
| » | DRAM speed select 4 wait states | J15 | pins 1 & 2 closed | 
| DRAM speed select 3 wait states | J15 | pins 2 & 3 closed | |
| » | NPU mode select 1 wait state | J16 | pins 1 & 2 closed | 
| NPU mode select 0 wait states | J16 | pins 2 & 3 closed | |
| » | Factory configured - do not alter | J19 | Open | 
| DRAM CONFIGURATION | ||||
| Size | Bank 0 | Bank 1 | Bank 2 | Bank 3 | 
| 1MB | (4) 256K x 9 | NONE | NONE | NONE | 
| 2MB | (4) 256K x 9 | (4) 256K x 9 | NONE | NONE | 
| 4MB | (4) 256K x 9 | (4) 256K x 9 | (4) 256K x 9 | (4) 256K x 9 | 
| 4MB | (4) 1M x 9 | NONE | NONE | NONE | 
| 8MB | (4) 1M x 9 | (4) 1M x 9 | NONE | NONE | 
| 16MB | (4) 1M x 9 | (4) 1M x 9 | (4) 1M x 9 | (4) 1M x 9 | 
| Note:Banks 2 & 3 are used when a 32-bit external memory card is installed. | ||||
| CACHE CONFIGURATION | |
| Size | Bank 0 | 
| 64KB | (8) 64K x 1 | 
| Note:Cache is factory installed and is not configurable. | |
| CMOS CONFIGURATION | ||||||||
| Setting | W1 | W2 | W3 | W4 | W5 | W6 | W7 | W8 | 
| Internal | 2 & 3 | 2 & 3 | 2 & 3 | 2 & 3 | 2 & 3 | 2 & 3 | 2 & 3 | 2 & 3 | 
| External | 1 & 2 | 1 & 2 | 1 & 2 | 1 & 2 | 1 & 2 | 1 & 2 | 1 & 2 | 1 & 2 | 
| Note: Pins designated should be in the closed position. | ||||||||