TANDY/RADIO SHACK
MFP/420s
| 
 Processor  | 
 80486SX/80487SX  | 
| 
 Processor Speed  | 
 20MHz  | 
| 
 Chip Set  | 
 Tandy  | 
| 
 Max. Onboard DRAM  | 
 32MB  | 
| 
 Cache  | 
 None  | 
| 
 BIOS  | 
 Phoenix/Grid  | 
| 
 Dimensions  | 
 355mm x 304mm  | 
| 
 I/O Options  | 
 Bus mouse port, floppy drive interface, IDE interface parallel port, serial port (2), VGA feature connector, VGA port  | 
| 
 NPU Options  | 
 4167  | 
| 
 VRAM CONFIGURATION  | |||
| 
 Size  | 
 VRAM  | 
 Location  | 
 SW1/switch 6  | 
| 
 512KB  | 
 (2) 44256  | 
 Bank 0  | 
 closed  | 
| 
 1024KB  | 
 (2) 44256  | 
 Banks 0 & 1  | 
 open  | 
| 
 CONNECTIONS  | |||
| 
 Purpose  | 
 Location  | 
 Purpose  | 
 Location  | 
| 
 External battery  | 
 BAT  | 
 Floppy drive interface  | 
 C6  | 
| 
 Board LED  | 
 BLED  | 
 IDE interface  | 
 C7  | 
| 
 VGA port  | 
 C1  | 
 Power LED  | 
 PLED  | 
| 
 Bus mouse port  | 
 C2  | 
 Reset switch  | 
 RES  | 
| 
 Parallel port  | 
 C3  | 
 Speaker  | 
 SPK  | 
| 
 Serial port 2  | 
 C4  | 
 Riser card  | 
 S1  | 
| 
 Serial port 1  | 
 C5  | ||
| 
 USER CONFIGURABLE SETTINGS  | |||
| 
 Function  | 
 Switch  | 
 Position  | |
| » | 
 On-board Video System enabled  | 
 SW1/switch 7 SW1/switch 8  | 
 closed open  | 
| 
 On-board Video System disabled  | 
 SW1/switch 7 SW1/switch 8  | 
 open closed  | |
| » | 
 Factory configured - do not alter  | 
 SW2/switch 1  | 
 open  | 
| » | 
 Factory configured - do not alter  | 
 SW2/switch 2  | 
 open  | 
| » | 
 Monitor type select color  | 
 SW2/switch 3  | 
 open  | 
| 
 Monitor type select monochrome  | 
 SW2/switch 3  | 
 closed  | |
| » | 
 Factory configured - do not alter  | 
 SW2/switch 4  | 
 open  | 
| 
 VIDEO SWITCH CONFIGURATION (SW1)  | |||||
| 
 Mode  | 
 switch 1  | 
 switch 2  | 
 switch 3  | 
 switch 4  | 
 switch 5  | 
| 
 56Hz vertical refresh 1 | 
 open  | 
 open  | 
 N/A  | 
 N/A  | 
 N/A  | 
| 
 60Hz vertical refresh 1 | 
 open  | 
 closed  | 
 N/A  | 
 N/A  | 
 N/A  | 
| 
 72Hz vertical refresh 1 | 
 closed  | 
 open  | 
 N/A  | 
 N/A  | 
 N/A  | 
| 
 Enable interlaced 2 | 
 N/A  | 
 N/A  | 
 open  | 
 open  | 
 N/A  | 
| 
 60Hz non-interlaced 2 | 
 N/A  | 
 N/A  | 
 open  | 
 closed  | 
 N/A  | 
| 
 72Hz non-interlaced 2 | 
 N/A  | 
 N/A  | 
 closed  | 
 open  | 
 N/A  | 
| 
 31.5KHz horizontal scan rate 3 | 
 N/A  | 
 N/A  | 
 N/A  | 
 N/A  | 
 open  | 
| 
 40KHz horizontal scan rate 3 | 
 N/A  | 
 N/A  | 
 N/A  | 
 N/A  | 
 closed  | 
| 
 Note 1 :When monitor resolution is 800 x 600.Note 2 :When monitor resolution is 1024 x 768.Note 3 :When monitor resolution is 640 x 480 or below. | |||||
| 
 DRAM CONFIGURATION  | ||
| 
 Size  | 
 Bank 0  | 
 Bank 1  | 
| 
 4MB  | 
 (4) 1M x 9  | 
 NONE  | 
| 
 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  | 
| 
 20MB  | 
 (4) 1M x 9  | 
 (4) 4M x 9  | 
| 
 32MB  | 
 (4) 4M x 9  | 
 (4) 4M x 9  |