UNITRON COMPUTER, INC.
486SX SYSTEM
| 
 Processor  | 
 80486SX/80486DX  | 
| 
 Processor Speed  | 
 25/33MHz  | 
| 
 Chip Set  | 
 UMC  | 
| 
 Max. Onboard DRAM  | 
 32MB  | 
| 
 SRAM Cache  | 
 32/128KB  | 
| 
 BIOS  | 
 Phoenix  | 
| 
 Dimensions  | 
 346mm x 218mm  | 
| 
 I/O Options  | 
 Floppy drive interface, game port, IDE interface, modem interface, parallel port, serial port (2), VGA port  | 
| 
 NPU Options  | 
 4167 (location unverified)  | 
| 
 CONNECTIONS  | |||
| 
 Purpose  | 
 Location  | 
 Purpose  | 
 Location  | 
| 
 Game port  | 
 C1  | 
 IDE interface  | 
 J22  | 
| 
 VGA port  | 
 C2  | 
 Modem interface  | 
 J23  | 
| 
 Parallel port  | 
 C3  | 
 Turbo LED  | 
 J26  | 
| 
 Serial port 2  | 
 C4  | 
 Power LED  | 
 J28  | 
| 
 Serial port 1  | 
 C5  | 
 Floppy drive interface  | 
 J31  | 
| 
 Fan power  | 
 J3  | ||
| 
 USER CONFIGURABLE SETTINGS  | |||
| 
 Function  | 
 Jumper  | 
 Position  | |
| » | 
 Serial port 1 (CN5) enabled  | 
 J18  | 
 pins 1 & 2 closed  | 
| 
 Serial port 1 (CN5) disabled  | 
 J18  | 
 pins 2 & 3 closed  | |
| » | 
 Serial port 1 (CN5) select COM1 (I/O address 3F8-3FFh)  | 
 J19  | 
 pins 1 & 2 closed  | 
| 
 Serial port 1 (CN5) select COM3 (I/O address 3E8-3EFh)  | 
 J19  | 
 pins 2 & 3 closed  | |
| » | 
 Parallel port (C3) select LPT1 interrupt IRQ7 at 378-37F  | 
 J20  | 
 pins 1 & 2 closed  | 
| 
 Parallel port (C3) select LPT2 interrupt IRQ5 at 278-27F  | 
 J20  | 
 pins 2 & 3 closed  | |
| » | 
 Parallel port (CN3) enabled  | 
 J21  | 
 pins 1 & 2 closed  | 
| 
 Parallel port (CN3) disabled  | 
 J21  | 
 pins 2 & 3 closed  | |
| » | 
 IDE interface (J22) enabled  | 
 J25  | 
 pins 1 & 2 closed  | 
| 
 IDE interface (J22) disabled  | 
 J25  | 
 pins 2 & 3 closed  | |
| » | 
 Floppy drive interface (J31) enabled  | 
 J27  | 
 pins 1 & 2 closed  | 
| 
 Floppy drive interface (J31) disabled  | 
 J27  | 
 pins 2 & 3 closed  | |
| » | 
 Serial port 2 (CN4) select COM2 (I/O address 2F8-2FFh)  | 
 J29  | 
 pins 1 & 2 closed  | 
| 
 Serial port 2 (CN4) select COM4 (I/O address 2E8-2EFh)  | 
 J29  | 
 pins 2 & 3 closed  | |
| » | 
 Serial port 2 (CN4) enabled  | 
 J30  | 
 pins 1 & 2 closed  | 
| 
 Serial port 2 (CN4) disabled  | 
 J30  | 
 pins 2 & 3 closed  | |
| 
 DRAM CONFIGURATION  | ||
| 
 Size  | 
 Bank 0  | 
 Bank 1  | 
| 
 1MB  | 
 (1) 256K x 36  | 
 NONE  | 
| 
 2MB  | 
 (1) 256K x 36  | 
 (1) 256K x 36  | 
| 
 3MB  | 
 (1) 512K x 36  | 
 (1) 256K x 36  | 
| 
 4MB  | 
 (1) 1M x 36  | 
 NONE  | 
| 
 5MB  | 
 (1) 256K x 36  | 
 (1) 1M x 36  | 
| 
 8MB  | 
 (1) 1M x 36  | 
 (1) 1M x 36  | 
| 
 12MB  | 
 (1) 2M x 36  | 
 (1) 1M x 36  | 
| 
 16MB  | 
 (1) 2M x 36  | 
 (1) 2M x 36  | 
| 
 32MB  | 
 (1) 4M x 36  | 
 (1) 4M x 36  | 
| 
 CPU TYPE CONFIGURATION  | ||
| 
 CPU  | 
 JP1  | 
 JP2  | 
| 
 80486DX  | 
 pins 1 & 2 closed  | 
 pins 1 & 2 and 3 & 4 closed  | 
| 
 80486SX  | 
 open  | 
 pins 2 & 3 closed  | 
| 
 Note:The location of jumpers JP1 and JP2 is unknown.  | ||
| 
 SRAM JUMPER CONFIGURATION  | |||||
| 
 Size  | 
 J7  | 
 J10  | 
 J11  | 
 J13  | 
 J14  | 
| 
 32KB  | 
 open  | 
 pins 1 & 2  | 
 pins 1 & 2  | 
 pins 1 & 2  | 
 pins 1 & 2  | 
| 
 128KB  | 
 closed  | 
 pins 2 & 3  | 
 pins 2 & 3  | 
 pins 2 & 3  | 
 pins 2 & 3  | 
| 
 Note:Pins designated should be in the closed postion.  | |||||
| 
 SRAM CONFIGURATION  | |||
| 
 Size  | 
 Cache SRAM  | 
 Location  | 
 TAG  | 
| 
 32KB  | 
 (4) 8K x 8  | 
 CACHE  | 
 (1) 8K x 8  | 
| 
 128KB  | 
 (4) 32K x 8  | 
 CACHE  | 
 (1) 32K x 8  | 
| 
 Note:This configuartion is unverified.  | |||
| 
 VRAM CONFIGURATION  | ||
| 
 Size  | 
 VRAM  | 
 Location  | 
| 
 256KB  | 
 (2) 44256  | 
 Bank 0  | 
| 
 512KB  | 
 (4) 44256  | 
 Banks 0 & 1  | 
| 
 1MB  | 
 (8) 44256  | 
 Banks 0, 1, 2 and 3  |