UNIDENTIFIED A486DX4/SIS III Processor AM486SX/80486SX/CX486DX/AM486DX/80486DX/AM486DX2/ 80486DX2/AM486DX4/80486DX4 Processor 20/25/33/40/50(internal)/50/66(internal)/75(internal)/ Speed 100(internal)MHz Chip Set SIS Video Chip None Set Maximum 64MB Onboard Memory Maximum Video None Memory Cache 32/64/128/256/512KB BIOS AMI Dimensions 254mm x 218mm I/O Options 32-bit VESA local bus slots (3) NPU Options None [Image] CONNECTIONS Purpose Location Purpose Location Power LED & keylock J1 Power LED LED1 Speaker J2 Turbo switch S1 Turbo LED J4 32-bit VESA local SL1 - SL3 bus slots Reset switch J5 USER CONFIGURABLE SETTINGS Function Label Position » Factory configured - do not alter J7 Unidentified » Factory configured - do not alter J9 Closed » Factory configured - do not alter J11 Open » Factory configured - do not alter J12 Open » Factory configured - do not alter JP17 Pins 1 & 2 closed RC pin used for break switch JP20 Pins 1 & 2 closed RC pin used for RC JP20 Pins 2 & 3 closed CPU type select any CPU type JP27 Open CPU type select CX486S2 only JP27 Closed Monitor type select CGA JP38 Closed Monitor type select JP38 Open monochrome/EGA/VGA » CMOS memory normal operation JP39 Pins 1 & 2 closed CMOS memory clear JP39 Pins 2 & 3 closed » Factory configured - do not alter JP43 Pins 2 & 3 closed » Factory configured - do not alter JP71 Open Flash BIOS not installed JP73 Pins 1 & 2 closed Flash BIOS installed JP73 Pins 2 & 3 closed » Factory configured - do not alter JP74 Unidentified » Factory configured - do not alter JP75 Unidentified » Factory configured - do not alter JP78 Pins 1 & 2 closed » Factory configured - do not alter JP79 Pins 2 & 3 closed Turbo disabled TBSW Pins 1 & 2 closed Turbo enabled TBSW Pins 2 & 3 closed Turbo enabled through S1 TBSW Pins 4 & 5 closed DRAM CONFIGURATION 1 Size Bank 0 1MB (4) 256K x 9 4MB (4) 1M x 9 16MB (4) 4M x 9 64MB (4) 16M x 9 DRAM CONFIGURATION 2 Size Bank 1 Bank 2 1MB (1) 256K x 36 None 2MB (1) 512K x 36 None 4MB (1) 1M x 36 None 4MB (1) 512K x 36 (1) 512K x 36 8MB (1) 2M x 36 None 8MB (1) 1M x 36 (1) 1M x 36 16MB (1) 4M x 36 None DRAM CONFIGURATION 2 (CON’T) Size Bank 1 Bank 2 16MB (1) 2M x 36 (1) 2M x 36 32MB (1) 8M x 36 None 32MB (1) 4M x 36 (1) 4M x 36 64MB (1) 8M x 36 (1) 8M x 36 DRAM JUMPER CONFIGURATION Configuration JP45 JP46 1 Pins 2 & 3 closed Closed 2 Pins 1 & 2 closed Open CACHE CONFIGURATION Size Bank 0 Bank 1 TAG 32KB (4) 8K x 8 None (1) 8K x 8 64KB (4) 8K x 8 (4) 8K x 8 (1) 8K x 8 128KB (4) 32K x 8 None (1) 8K x 8 256KB (A) (4) 32K x 8 (4) 32K x 8 (1) 32K x 8 256KB (B) (4) 64K x 8 None (1) 32K x 8 512KB (4) 128K x 8 None (1) 32K x 8 CACHE JUMPER CONFIGURATION Size JP30 JP31 JP32 JP34 JP35 JP36 JP81 32KB 1 & 2 1 & 2 1 & 2 Open 1 & 2 1 & 2 2 & 3 64KB 2 & 3 1 & 2 1 & 2 1 & 2 2 & 3 1 & 2 2 & 3 128KB 2 & 3 2 & 3 1 & 2 2 & 3, 1 & 2 2 & 3 2 & 3 4 & 5 256KB 2 & 3 2 & 3 2 & 3 1 & 2, 2 & 3 2 & 3 2 & 3 (A) 3 & 4 256KB 2 & 3 2 & 3 2 & 3 2 & 3, 1 & 2 2 & 3 2 & 3 (B) 4 & 5 512KB 2 & 3 2 & 3 2 & 3 2 & 3, 1 & 2 2 & 3 1 & 2 4 & 5 Note: Pins designated should be in the closed position. CPU SPEED SELECTION Speed JP5 JP6 JP7 20MHz Closed Open Closed 25MHz Closed Closed Open 33MHz Open Closed Closed 40MHz Closed Open Open 50iMHz Closed Closed Open 50MHz Open Open Closed 66iMHz Open Closed Closed 75iMHz Closed Closed Open 100iMHz Open Closed Closed CPU TYPE SELECTION Type J13 JP8 JP10 JP12 JP13 AM486SX Closed 2 & 3 2 & 3 Open Open 80486SX Closed 2 & 3 2 & 3 Open Open CX486DX Open 2 & 3 2 & 3 2 & 3 2 & 3 AM486DX Closed 2 & 3 2 & 3 Open Open 80486DX Closed 2 & 3 2 & 3 Open Open AM486DX2 Closed 2 & 3 2 & 3 Open Open 80486DX2 Closed 2 & 3 2 & 3 Open Open AM486DX4 Closed 2 & 3 Open Open Open 80486DX4 Closed 2 & 3 Open Open Open Note: Pins designated should be in the closed position. CPU TYPE SELECTION (CON’T) Type JP18 JP19 JP24 JP25 JP28 AM486SX 1 & 2 2 & 3 4 & 5 2 & 3 1 & 2 80486SX 1 & 2 2 & 3 4 & 5 2 & 3 1 & 2 CX486DX 2 & 3 1 & 2 2 & 3 1 & 2, 3 Open & 4 AM486DX 1 & 2 2 & 3 4 & 5 2 & 3 1 & 2 80486DX 1 & 2 2 & 3 4 & 5 2 & 3 1 & 2 AM486DX2 1 & 2 2 & 3 4 & 5 2 & 3 1 & 2 80486DX2 1 & 2 2 & 3 4 & 5 2 & 3 1 & 2 AM486DX4 1 & 2 2 & 3 4 & 5 2 & 3 1 & 2 80486DX4 1 & 2 2 & 3 4 & 5 2 & 3 1 & 2 Note: Pins designated should be in the closed position. CPU TYPE SELECTION (CON’T) Type JP29 JP33 JP37 JP40 AM486SX 3 & 4 2 & 3 Open 1 & 2 or 2 & 3 80486SX 3 & 4 2 & 3 Open 1 & 2 or 2 & 3 CX486DX 2 & 3 1 & 2 3 & 4 1 & 2 AM486DX 3 & 4 1 & 2, 3 & 3 & 4 1 & 2 or 2 4 & 3 80486DX 3 & 4 1 & 2, 3 & 3 & 4 1 & 2 or 2 4 & 3 AM486DX2 3 & 4 1 & 2, 3 & 3 & 4 1 & 2 or 2 4 & 3 80486DX2 3 & 4 1 & 2, 3 & 3 & 4 1 & 2 or 2 4 & 3 AM486DX4 3 & 4 1 & 2, 3 & 3 & 4 1 & 2 or 2 4 & 3 80486DX4 3 & 4 1 & 2, 3 & 3 & 4 1 & 2 or 2 4 & 3 Note: Pins designated should be in the closed position. CPU MULTIPLIER SELECTION Multiplier JP44 2x Pins 1 & 2 closed 2.5x Pins 2 & 3 closed 3x Open CPU VOLTAGE SELECTION Voltage Setting JP80 3.45v UMB on board Auto detect 5v UMB on board Auto detect 3.45v UMB not on board No support 5v UMB not on board Closed VL BUS WAIT STATE SELECTION Setting JP4 0 Pins 1 & 2 closed 1 Pins 2 & 3 closed VL BUS SPEED SELECTION Speed JP3 <= 33MHz Pins 1 & 2 closed >33 MHz Pins 2 & 3 closed