TANDY/RADIO SHACK
2500 SX/20
| 
 Processor  | 
 80386SX  | 
| 
 Processor Speed  | 
 20MHz  | 
| 
 Chip Set  | 
 Unidentified  | 
| 
 Video Chip Set  | 
 Unidentified  | 
| 
 Maximum Onboard Memory  | 
 5MB  | 
| 
 Maximum Video Memory  | 
 Unidentified  | 
| 
 Cache  | 
 None  | 
| 
 BIOS  | 
 Unidentified  | 
| 
 Dimensions  | 
 254mm x 218mm  | 
| 
 I/O Options  | 
 Floppy drive interface, IDE interface, serial port, parallel port, PS/2 mouse port, riser slot  | 
| 
 NPU Options  | 
 80387SX  | 
| 
 CONNECTIONS  | |||
| 
 Purpose  | 
 Location  | 
 Purpose  | 
 Location  | 
| 
 Floppy drive interface  | 
 CN1  | 
 IDE interface LED  | 
 J1  | 
| 
 IDE interface  | 
 CN2  | 
 Riser slot  | 
 SL1  | 
| 
 The location of the serial port, parallel port and PS/2 mouse port is unidentified.  | |||
| 
 USER CONFIGURABLE SETTINGS  | |||
| 
 Function  | 
 Label  | 
 Position  | |
| 
 »  | 
 Audio input source select microphone  | 
 JP1  | 
 Pins 1 & 2 closed  | 
| 
 Audio input source select line level  | 
 JP1  | 
 Pins 2 & 3 closed  | |
| 
 »  | 
 Audio output source select headphone  | 
 JP2  | 
 Pins 1 & 2 closed  | 
| 
 Audio output source select line level  | 
 JP2  | 
 Pins 2 & 3 closed  | |
| 
 »  | 
 Monitor type select VGA analog or standard multiple frequency  | 
 JP3  | 
 Pins 1 & 2 closed  | 
| 
 Monitor type select non standard multiple frequency  | 
 JP3  | 
 Pins 2 & 3 closed  | |
| 
 »  | 
 VGA BIOS select PS/2 mode  | 
 JP4  | 
 Pins 2 & 3 closed  | 
| 
 VGA BIOS select AT mode  | 
 JP4  | 
 Pins 1 & 2 closed  | |
| 
 »  | 
 Video IRQ9 disabled  | 
 JP5  | 
 Open  | 
| 
 Video IRQ9 enabled  | 
 JP5  | 
 Pins 1 & 2 closed  | |
| 
 »  | 
 On board video enabled  | 
 JP6  | 
 Pins 1 & 2 closed  | 
| 
 On board video disabled  | 
 JP6  | 
 Pins 2 & 3 closed  | |
| 
 DRAM CONFIGURATION  | |||
| 
 Size  | 
 Bank 0  | 
 Bank 1  | 
 Bank 2  | 
| 
 1.5MB  | 
 1MB  | 
 (2) 256K x 9  | 
 None  | 
| 
 2MB  | 
 1MB  | 
 (2) 256K x 9  | 
 (2) 256K x 9  | 
| 
 3MB  | 
 1MB  | 
 (2) 1M x 9  | 
 None  | 
| 
 5MB  | 
 1MB  | 
 (2) 1M x 9  | 
 (2) 1M x 9  | 
| 
 Note: Bank 0 is factory installed and is not configurable. The location is unidentified.  | |||