TANDY/RADIO SHACK 3100, MMPC MODEL 10/20 SENSATION! (250-1651) Processor 80486SX/80487SX/ODP486/80486DX2 Processor Speed 25/33/50(internal)/66(internal)MHz Chip Set Unidentified Video Chip Set Unidentified Maximum Onboard 64MB Memory Maximum Video 1MB Memory Cache None BIOS Unidentified Dimensions 254mm x 218mm I/O Options Floppy drive interface, IDE interface, parallel port, PS/2 mouse port, serial ports (2), VGA feature connector, VGA port, riser slot NPU Options None [Image] CONNECTIONS Purpose Location Purpose Location VGA port CN1 IDE interface CN6 Parallel port CN2 Floppy drive interface CN7 Serial port 2 CN3 VGA feature connector CN8 Serial port 1 CN4 Riser slot SL1 PS/2 mouse port CN5 IDE interface LED W2 USER CONFIGURABLE SETTINGS Function Label Position Parallel port IRQ select IRQ7 W5 Pins 1 & 2 closed Parallel port IRQ select IRQ5 W5 Pins 2 & 3 closed Parallel port IRQ disabled W5 Open » On board video enabled W8 Pins 2 & 3 closed On board video disabled W8 Pins 1 & 2 closed » VGA IRQ disabled W9 Open VGA IRQ enabled W9 Closed DRAM CONFIGURATION Size Bank 0 Bank 1 Bank 2 Bank 3 4MB (1) 1M x 32 None None None 5MB (1) 1M x 32 (1) 256K x None None 32 6MB (1) 1M x 32 (1) 256K x (1) 256K x None 32 32 6MB (1) 1M x 32 (1) 512K x None None 32 7MB (1) 1M x 32 (1) 256K x (1) 256K x (1) 256K x 32 32 32 7MB (1) 1M x 32 (1) 512K x (1) 256K x None 32 32 8MB (1) 1M x 32 (1) 512K x (1) 256K x (1) 256K x 32 32 32 8MB (1) 1M x 32 None (1) 512K x (1) 512K x 32 32 8MB (1) 1M x 32 (1) 1M x 32 None None 8MB (1) 2M x 32 None None None 9MB (1) 1M x 32 (1) 256K x (1) 512K x (1) 512K x 32 32 32 9MB (1) 1M x 32 (1) 1M x 32 (1) 256K x None 32 9MB (1) 2M x 32 (1) 256K x None None 32 10MB (1) 1M x 32 (1) 512K x (1) 512K x (1) 512K x 32 32 32 10MB (1) 1M x 32 (1) 1M x 32 (1) 256K x (1) 256K x 32 32 10MB (1) 1M x 32 (1) 1M x 32 (1) 512K x None 32 10MB (1) 2M x 32 None (1) 256K x (1) 256K x 32 32 10MB (1) 2M x 32 (1) 512K x None None 32 11MB (1) 1M x 32 (1) 1M x 32 (1) 512K x (1) 256K x 32 32 11MB (1) 2M x 32 (1) 256K x (1) 256K x (1) 256K x 32 32 32 11MB (1) 2M x 32 (1) 512K x (1) 256K x None 32 32 12MB (1) 1M x 32 (1) 1M x 32 (1) 512K x (1) 512K x 32 32 12MB (1) 1M x 32 (1) 1M x 32 (1) 1M x 32 None 12MB (1) 2M x 32 (1) 512K x (1) 256K x (1) 256K x 32 32 32 12MB (1) 2M x 32 None (1) 512K x (1) 512K x 32 32 12MB (1) 2M x 32 (1) 1M x 32 None None 13MB (1) 1M x 32 (1) 1M x 32 (1) 1M x 32 (1) 256K x 32 13MB (1) 2M x 32 (1) 256K x (1) 512K x (1) 512K x 32 32 32 13MB (1) 2M x 32 (1) 1M x 32 (1) 256K x None 32 14MB (1) 1M x 32 (1) 1M x 32 (1) 1M x 32 (1) 512K x 32 14MB (1) 2M x 32 (1) 512K x (1) 512K x (1) 512K x 32 32 32 14MB (1) 2M x 32 (1) 1M x 32 (1) 256K x (1) 256K x 32 32 DRAM CONFIGURATION (CON’T) Size Bank 0 Bank 1 Bank 2 Bank 3 14MB (1) 2M x 32 (1) 1M x 32 (1) 512K x None 32 15MB (1) 2M x 32 (1) 1M x 32 (1) 512K x (1) 256K x 32 32 16MB (1) 1M x 32 (1) 1M x 32 (1) 1M x 32 (1) 1M x 32 16MB (1) 2M x 32 (1) 1M x 32 (1) 512K x (1) 512K x 32 32 16MB (1) 2M x 32 None (1) 1M x 32 (1) 1M x 32 16MB (1) 2M x 32 (1) 2M x 32 None None 16MB (1) 4M x 32 None None None 17MB (1) 2M x 32 (1) 256K x (1) 1M x 32 (1) 1M x 32 32 17MB (1) 2M x 32 (1) 2M x 32 (1) 256K x None 32 17MB (1) 4M x 32 (1) 256K x None None 32 18MB (1) 2M x 32 (1) 512K x (1) 1M x 32 (1) 1M x 32 32 18MB (1) 2M x 32 (1) 2M x 32 (1) 256K x (1) 256K x 32 32 18MB (1) 2M x 32 (1) 2M x 32 (1) 512K x None 32 18MB (1) 4M x 32 (1) 256K x (1) 256K x None 32 32 18MB (1) 4M x 32 (1) 512K x None None 32 19MB (1) 2M x 32 (1) 2M x 32 (1) 512K x (1) 256K x 32 32 19MB (1) 4M x 32 (1) 256K x (1) 256K x (1) 256K x 32 32 32 19MB (1) 4M x 32 (1) 512K x (1) 256K x None 32 32 20MB (1) 2M x 32 (1) 1M x 32 (1) 1M x 32 (1) 1M x 32 20MB (1) 2M x 32 (1) 2M x 32 (1) 512K x (1) 512K x 32 32 20MB (1) 2M x 32 (1) 2M x 32 (1) 1M x 32 None 20MB (1) 4M x 32 (1) 512K x (1) 256K x (1) 256K x 32 32 32 20MB (1) 4M x 32 None (1) 512K x (1) 512K x 32 32 20MB (1) 4M x 32 (1) 1M x 32 None None 21MB (1) 2M x 32 (1) 2M x 32 (1) 1M x 32 (1) 256K x 32 21MB (1) 4M x 32 (1) 256K x (1) 512K x (1) 512K x 32 32 32 21MB (1) 4M x 32 (1) 1M x 32 (1) 256K x None 32 22MB (1) 2M x 32 (1) 2M x 32 (1) 1M x 32 (1) 512K x 32 22MB (1) 4M x 32 (1) 512K x (1) 512K x (1) 512K x 32 32 32 22MB (1) 4M x 32 (1) 1M x 32 (1) 256K x (1) 256K x 32 32 22MB (1) 4M x 32 (1) 1M x 32 (1) 512K x None 32 23MB (1) 4M x 32 (1) 1M x 32 (1) 512K x (1) 256K x 32 32 24MB (1) 2M x 32 (1) 2M x 32 (1) 1M x 32 (1) 1M x 32 24MB (1) 2M x 32 (1) 2M x 32 (1) 2M x 32 None 24MB (1) 4M x 32 (1) 1M x 32 (1) 512K x (1) 512K x 32 32 24MB (1) 4M x 32 (1) 1M x 32 (1) 1M x 32 None 24MB (1) 4M x 32 (1) 2M x 32 None None 25MB (1) 2M x 32 (1) 2M x 32 (1) 2M x 32 (1) 256K x 32 25MB (1) 4M x 32 (1) 1M x 32 (1) 1M x 32 (1) 256K x 32 25MB (1) 4M x 32 (1) 2M x 32 (1) 256K x None 32 26MB (1) 2M x 32 (1) 2M x 32 (1) 2M x 32 (1) 512K x 32 26MB (1) 4M x 32 (1) 1M x 32 (1) 1M x 32 (1) 512K x 32 DRAM CONFIGURATION (CON’T) Size Bank 0 Bank 1 Bank 2 Bank 3 26MB (1) 4M x 32 (1) 2M x 32 (1) 256K x (1) 256K x 32 32 26MB (1) 4M x 32 (1) 2M x 32 (1) 512K x None 32 27MB (1) 4M x 32 (1) 2M x 32 (1) 512K x (1) 256K x 32 32 28MB (1) 2M x 32 (1) 2M x 32 (1) 2M x 32 (1) 1M x 32 28MB (1) 4M x 32 (1) 1M x 32 (1) 1M x 32 (1) 1M x 32 28MB (1) 4M x 32 (1) 2M x 32 (1) 512K x (1) 512K x 32 32 28MB (1) 4M x 32 (1) 2M x 32 (1) 1M x 32 None 29MB (1) 4M x 32 (1) 2M x 32 (1) 1M x 32 (1) 256K x 32 30MB (1) 4M x 32 (1) 2M x 32 (1) 1M x 32 (1) 512K x 32 32MB (1) 2M x 32 (1) 2M x 32 (1) 2M x 32 (1) 2M x 32 32MB (1) 4M x 32 (1) 2M x 32 (1) 1M x 32 (1) 1M x 32 32MB (1) 4M x 32 None (1) 2M x 32 (1) 2M x 32 32MB (1) 4M x 32 (1) 4M x 32 None None 33MB (1) 4M x 32 (1) 256K x (1) 2M x 32 (1) 2M x 32 32 33MB (1) 4M x 32 (1) 4M x 32 (1) 256K x None 32 34MB (1) 4M x 32 (1) 512K x (1) 2M x 32 (1) 2M x 32 32 34MB (1) 4M x 32 (1) 4M x 32 (1) 256K x (1) 256K x 32 32 34MB (1) 4M x 32 (1) 4M x 32 (1) 512K x None 32 35MB (1) 4M x 32 (1) 4M x 32 (1) 512K x (1) 256K x 32 32 36MB (1) 4M x 32 (1) 1M x 32 (1) 2M x 32 (1) 2M x 32 36MB (1) 4M x 32 (1) 4M x 32 (1) 512K x (1) 512K x 32 32 36MB (1) 4M x 32 (1) 4M x 32 (1) 1M x 32 None 37MB (1) 4M x 32 (1) 4M x 32 (1) 1M x 32 (1) 256K x 32 38MB (1) 4M x 32 (1) 4M x 32 (1) 1M x 32 (1) 512K x 32 40MB (1) 4M x 32 (1) 2M x 32 (1) 2M x 32 (1) 2M x 32 40MB (1) 4M x 32 (1) 4M x 32 (1) 1M x 32 (1) 1M x 32 40MB (1) 4M x 32 (1) 4M x 32 (1) 2M x 32 None 41MB (1) 4M x 32 (1) 4M x 32 (1) 2M x 32 (1) 256K x 32 42MB (1) 4M x 32 (1) 4M x 32 (1) 2M x 32 (1) 512K x 32 44MB (1) 4M x 32 (1) 4M x 32 (1) 2M x 32 (1) 1M x 32 48MB (1) 4M x 32 (1) 4M x 32 (1) 2M x 32 (1) 2M x 32 48MB (1) 4M x 32 (1) 4M x 32 (1) 4M x 32 None 49MB (1) 4M x 32 (1) 4M x 32 (1) 4M x 32 (1) 256K x 32 50MB (1) 4M x 32 (1) 4M x 32 (1) 4M x 32 (1) 512K x 32 52MB (1) 4M x 32 (1) 4M x 32 (1) 4M x 32 (1) 1M x 32 56MB (1) 4M x 32 (1) 4M x 32 (1) 4M x 32 (1) 2M x 32 64MB (1) 4M x 32 (1) 4M x 32 (1) 4M x 32 (1) 4M x 32 VIDEO MEMORY CONFIGURATION Size Bank 0 Bank 1 512KB 512KB None 1MB 512KB 512KB Note: The size of the video memory chips are unidentified. CPU SPEED SELECTION Speed W1 25MHz Closed 33MHz Open 50iMHz Closed 66iMHz Open CPU TYPE SELECTION Type W6 W7 80486SX Pins 2 & 3 closed Pins 1 & 2 closed 80487SX Pins 1 & 2 closed Pins 2 & 3 closed ODP486 Pins 1 & 2 closed Pins 1 & 2 closed 80486DX Pins 1 & 2 closed Pins 1 & 2 closed 80486DX2 Pins 1 & 2 closed Pins 1 & 2 closed Note: W7 may not be present on all boards. SERIAL PORT 1 ADDRESS SELECTION Setting IRQ W3 » COM1/COM3 IRQ4 Pins 1 & 2 closed COM3 IRQ11 Pins 2 & 3 closed SERIAL PORT 2 ADDRESS SELECTION Setting IRQ W4 » COM2/COM4 (2F8h) IRQ3 Pins 1 & 2 closed COM4 IRQ10 Pins 2 & 3 closed