COMMODORE BUSINESS MACHINES, INC.
386DX System (Part #368954-01)
| 
 Processor  | 
 80386DX  | 
| 
 Processor Speed  | 
 25/33MHz  | 
| 
 Chip Set  | 
 PC CHIPS  | 
| 
 Max. Onboard DRAM  | 
 32MB  | 
| 
 SRAM Cache  | 
 64/128/256KB  | 
| 
 BIOS  | 
 AMI  | 
| 
 Dimensions  | 
 330mm x 218mm  | 
| 
 I/O Options  | 
 Floppy drive interface, IDE interface, parallel port, PS/2 mouse port, serial port (2), VGA port  | 
| 
 NPU Options  | 
 80387/3167  | 
| 
 CONNECTIONS  | |||
| 
 Purpose  | 
 Location  | 
 Purpose  | 
 Location  | 
| 
 VGA port  | 
 C1  | 
 PS/2 style mouse port  | 
 C5  | 
| 
 Serial port 1  | 
 C2  | 
 Floppy drive interface  | 
 C6  | 
| 
 Serial port 2  | 
 C3  | 
 Hard drivve interface  | 
 C7  | 
| 
 Parallel port  | 
 C4  | 
 Basic connectors (pins unknown)  | 
 C8  | 
| 
 USER CONFIGURABLE SETTINGS  | |||
| 
 Function  | 
 Jumper  | 
 Position  | |
| » | 
 Combined BIOS enabled  | 
 J7  | 
 closed  | 
| 
 Combined BIOS disabled  | 
 J7  | 
 open  | |
| » | 
 Monitor type select color  | 
 J14 J20  | 
 pins 1 & 2 closed pins 2 & 3 closed  | 
| 
 Monitor type select color disabled  | 
 J14 J20  | 
 pins 2 & 3 closed pins 1 & 2 closed  | |
| » | 
 Factory configured - do not alter  | 
 J17  | 
 unknown  | 
| » | 
 Factory configured - do not alter  | 
 J18  | 
 unknown  | 
| » | 
 Factory configured - do not alter  | 
 J19  | 
 unknown  | 
| » | 
 Factory configured - do not alter  | 
 J31  | 
 unknown  | 
| » | 
 VGA select zero wait states  | 
 J23  | 
 closed  | 
| 
 VGA select zero wait states disabled  | 
 J23  | 
 open  | |
| » | 
 Monitor type select monochrome  | 
 J30  | 
 open  | 
| 
 Monitor type select monochrome disabled  | 
 J30  | 
 closed  | |
| » | 
 Floppy drive interface (C6) enabled  | 
 J41  | 
 pins 1 & 2 closed  | 
| » | 
 Floppy drive interface (C6) disabled  | 
 J41  | 
 pins 2 & 3 closed  | 
| » | 
 Hard drive interface (C7) enabled  | 
 J43 J44  | 
 closed closed  | 
| 
 Hard drive interface (C7) disabled  | 
 J43 J44  | 
 open open  | |
| 
 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  | 
| 
 5MB  | 
 (4) 1M x 9  | 
 (4) 256K x 9  | 
| 
 8MB  | 
 (4) 1M x 9  | 
 (4) 1M x 9  | 
| 
 16MB  | 
 (4) 4M x 9  | 
 NONE  | 
| 
 17MB  | 
 (4) 256K x 9  | 
 (4) 4M x 9  | 
| 
 17MB  | 
 (4) 4M x 9  | 
 (4) 256K x 9  | 
| 
 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  | 
| 
 SERIAL PORT CONFIGURATION  | |||
| 
 Function  | 
 Jumper  | 
 Position  | |
| » | 
 Serial port 1 (C2) enabled at interrupt IRQ4  | 
 J27  | 
 closed  | 
| 
 Serial port 1 (C2) disabled  | 
 J27  | 
 open  | |
| » | 
 Serial port 2 (C3) enabled at interrupt select IRQ3  | 
 J29  | 
 closed  | 
| 
 Serial port 2 (C3) disabled  | 
 J29  | 
 open  | |
| 
 
 Serial port 1 (C2) select COM1  | 
 J38 J39 J40  | 
 pins 1 & 2 closed pins 1 & 2 closed pins 1 & 2 closed  | |
| 
 
 Serial port 2 (C3) select COM2  | 
 J38 J39 J40  | 
 pins 1 & 2 closed pins 1 & 2 closed pins 1 & 2 closed  | |
| 
 
 Serial port 1 (C2) select COM2  | 
 J38 J39 J40  | 
 pins 1 & 2 closed pins 1 & 2 closed pins 2 & 3 closed  | |
| 
 
 Serial port 1 (C2) select COM1  | 
 J38 J39 J40  | 
 pins 1 & 2 closed pins 1 & 2 closed pins 2 & 3 closed  | |
| 
 
 Serial port 1 (C2) select COM1  | 
 J38 J39 J40  | 
 pins 2 & 3 closed pins 1 & 2 closed pins 1 & 2 closed  | |
| 
 
 Serial port 2 (C3) disabled  | 
 J38 J39 J40  | 
 pins 2 & 3 closed pins 1 & 2 closed pins 1 & 2 closed  | |
| 
 
 Serial port 1 (C2) disabled  | 
 J38 J39 J40  | 
 pins 1 & 2 closed pins 2 & 3 closed pins 2 & 3 closed  | |
| 
 
 Serial port 2 (C3) select COM1  | 
 J38 J39 J40  | 
 pins 1 & 2 closed pins 2 & 3 closed pins 2 & 3 closed  | |
| 
 
 Serial port 1 (C2) disabled  | 
 J38 J39 J40  | 
 pins 1 & 2 closed pins 2 & 3 closed pins 1 & 2 closed  | |
| 
 
 Serial port 2 (C3) select COM2  | 
 J38 J39 J40  | 
 pins 1 & 2 closed pins 2 & 3 closed pins 1 & 2 closed  | |
| 
 
 Serial port 1 (C2) select COM2  | 
 J38 J39 J40  | 
 pins 2 & 3 closed pins 1 & 2 closed pins 2 & 3 closed  | |
| 
 
 Serial port 2 (C3) disabled  | 
 J38 J39 J40  | 
 pins 2 & 3 closed pins 1 & 2 closed pins 2 & 3 closed  | |
| 
 
 Serial port 1 & 2 disabled  | 
 J38 J39 J40  | 
 pins 2 & 3 closed pins 2 & 3 closed pins 2 & 3 closed  | |
| 
 PARALLEL PORT CONFIGURATION (C4)  | |||
| 
 Function  | 
 Jumper  | 
 Position  | |
| » | 
 Parallel port enabled at IRQ7  | 
 J28  | 
 pins 2 & 3 closed  | 
| 
 Parallel port enabled at IRQ5  | 
 J28  | 
 pins 1 & 2 closed  | |
| 
 Parallel port enable LPT1  | 
 J36 J37  | 
 pins 2 & 3 closed pins 1 & 2 closed  | |
| 
 Parallel port enable LPT2  | 
 J36 J37  | 
 pins 1 & 2 closed pins 1 & 2 closed  | |
| 
 Parallel port enable LPT3  | 
 J36 J37  | 
 pins 1 & 2 closed pins 2 & 3 closed  | |
| 
 Parallel port disabled  | 
 J36 J37  | 
 pins 2 & 3 closed pins 2 & 3 closed  | |
| 
 SRAM JUMPER CONFIGURATION  | ||||||||
| 
 
 Size  | 
 Jumper J8  | 
 Jumper J9  | 
 Jumper J11  | 
 Jumper J12  | 
 Jumper J13  | 
 Jumper J15  | 
 Jumper J16  | 
 Jumper J42  | 
| 
 
 Disabled  | 
 
 closed  | 
 pins 1 & 2 closed  | 
 pins 1 & 2 closed  | 
 
 N/A  | 
 
 N/A  | 
 
 open  | 
 
 N/A  | 
 
 N/A  | 
| 
 
 64KB  | 
 
 closed  | 
 pins 2 & 3 closed  | 
 pins 2 & 3 closed  | 
 pins 1 & 2 closed  | 
 pins 1 & 2 closed  | 
 
 closed  | 
 pins 2 & 3 closed  | 
 pins 1 & 2 closed  | 
| 
 
 128KB  | 
 
 closed  | 
 pins 2 & 3 closed  | 
 pins 2 & 3 closed  | 
 pins 2 & 3 closed  | 
 pins 1 & 2 closed  | 
 
 closed  | 
 
 open  | 
 pins 2 & 3 closed  | 
| 
 
 256KB  | 
 
 closed  | 
 pins 2 & 3 closed  | 
 pins 2 & 3 closed  | 
 pins 2 & 3 closed  | 
 pins 1 & 2 closed  | 
 
 closed  | 
 pins 1 & 2 closed  | 
 pins 2 & 3 closed  | 
| 
 SRAM CONFIGURATION  | ||||
| 
 Size  | 
 Cache SRAM  | 
 Location  | 
 TAG (UAA)  | 
 TAG (U11)  | 
| 
 64KB  | 
 (8) 8K x 8  | 
 Banks 0 & 1  | 
 (1) 8K x 8  | 
 (1) 8K x 8  | 
| 
 128KB  | 
 (4) 32K x 8  | 
 Bank 0  | 
 (1) 32K x 8  | 
 NONE  | 
| 
 256KB  | 
 (8) 32K x 8  | 
 Banks 0 & 1  | 
 (1) 32K x 8  | 
 (1) 32K x 8  | 
| 
 VIDEO SWITCH CONFIGURATION (SW1)  | |||||
| 
 Mode  | 
 switch 1  | 
 switch 2  | 
 switch 3  | 
 switch 4  | 
 switch 5  | 
| 
 56Hz vertical refresh  | 
 open  | 
 open  | 
 N/A  | 
 N/A  | 
 N/A  | 
| 
 60Hz vertical refresh  | 
 open  | 
 closed  | 
 N/A  | 
 N/A  | 
 N/A  | 
| 
 72Hz vertical refresh  | 
 closed  | 
 open  | 
 N/A  | 
 N/A  | 
 N/A  | 
| 
 Enable interlaced  | 
 N/A  | 
 N/A  | 
 open  | 
 open  | 
 N/A  | 
| 
 60Hz non-interlaced  | 
 N/A  | 
 N/A  | 
 open  | 
 closed  | 
 N/A  | 
| 
 72Hz non-interlaced  | 
 N/A  | 
 N/A  | 
 closed  | 
 open  | 
 N/A  | 
| 
 31.5KHz horizontal scan rate  | 
 N/A  | 
 N/A  | 
 N/A  | 
 N/A  | 
 open  | 
| 
 40KHz horizontal scan rate  | 
 N/A  | 
 N/A  | 
 N/A  | 
 N/A  | 
 closed  | 
| 
 VRAM CONFIGURATION  | ||
| 
 Size  | 
 VRAM  | 
 SW1/switch 6  | 
| 
 512KB  | 
 (2) 256K x 4  | 
 closed  | 
| 
 1MB  | 
 (4) 256K x 4  | 
 open  |