DTK COMPUTER, INC.
TURBO 640
| Processor | 8088-2 | 
| Processor Speed | 8MHz | 
| Chip Set | None | 
| Max. Onboard DRAM | 640K | 
| Cache | None | 
| BIOS | DTK/ERSO | 
| Dimensions | 330mm x 218mm | 
| I/O Options | None | 
| NPU Options | 8087-2 | 
 
| CONNECTIONS | |||
| Purpose | Location | Purpose | Location | 
| Reset switch | JP1 | Turbo switch | JP5 | 
| Power LED & turbo LED | JP2 | Keylock | JP8 | 
| Speaker | JP4 | ||
| USER CONFIGURABLE SETTINGS | |||
| Function | Jumper/Switch | Position | |
| » | Factory configured - do not alter | SW1/switch 1 | Off | 
| » | NPU absent | SW1/switch 2 | Off | 
| NPU present | SW1/switch 2 | On | |
| DRAM CONFIGURATION | ||||
| Size | Bank 0 | Bank 1 | Bank 2 | Bank 3 | 
| 64KB | (9) 4164 | NONE | NONE | NONE | 
| 128KB | (9) 4164 | (9) 4164 | NONE | NONE | 
| 192KB | (9) 4164 | (9) 4164 | (9) 4164 | NONE | 
| 256KB | (9) 4164 | (9) 4164 | (9) 4164 | (9) 4164 | 
| 256KB | (9) 41256 | NONE | NONE | NONE | 
| 512KB | (9) 41256 | (9) 41256 | NONE | NONE | 
| 576KB | (9) 41256 | (9) 41256 | (9) 4164 | NONE | 
| 640KB | (9) 41256 | (9) 41256 | (9) 4164 | (9) 4164 | 
| DRAM JUMPER CONFIGURATION | ||||||
| Size | JPA | JPB | JPC | JPD | JPE | JPF | 
| 64KB | Closed | Closed | Open | Open | Open | Closed | 
| 128KB | Closed | Closed | Open | Open | Open | Closed | 
| 192KB | Closed | Closed | Open | Open | Open | Closed | 
| 256KB (using 4164) | Closed | Closed | Open | Open | Open | Closed | 
| 256KB (using 41256) | Open | Open | Closed | Closed | Closed | Open | 
| 512KB | Open | Open | Closed | Closed | Closed | Open | 
| 576KB | Open | Open | Closed | Closed | Closed | Open | 
| 640KB | Open | Open | Closed | Closed | Closed | Open | 
| CPU SPEED CONFIGURATION | ||
| Setting | JP6 | JP7 | 
| Switchable from turbo switch | Closed | Open | 
| Switchable from keyboard | Open | Closed | 
| FLOPPY DRIVE CONFIGURATION | ||
| Drives installed | SW1/7 | SW1/8 | 
| 1 | On | On | 
| 2 | Off | On | 
| 3 | On | Off | 
| 4 | Off | Off | 
| MONITOR CONFIGURATION | ||
| Type | SW1/5 | SW1/6 | 
| EGA or none | On | On | 
| 40 x 25 CGA | Off | On | 
| 80 x 25 CGA | On | Off | 
| Monochrome | Off | Off |