UNIDENTIFIED STC-SIS486C-DX/SX Processor 80486SX/80487SX/80486DX Processor Speed 20/25/33/50MHz Chip Set SIS Max. onboard DRAM 32MB Cache 32/64/128/256KB BIOS AMI Dimensions 218mm x 218mm I/O Options None NPU Options None [Image] CONNECTIONS Purpose Location Purpose Location External battery J1 Turbo LED J6 Power LED & keylock J3 Turbo switch J7 Speaker J4 Reset switch J8 Unknown J5 USER CONFIGURABLE SETTINGS Function Jumper Position » CMOS memory normal operation J1 pins 2 & 3 (internal battery) closed CMOS memory normal operation J1 pins 1 & 4 (external battery) closed CMOS memory clear J1 Open » Monitor type select color J2 Closed Monitor type select monochrome J2 Open » CPU speed select iOSC/1 J9 pins 1 & 2 closed CPU speed select iOSC/2 J9 pins 2 & 3 closed » Turbo switch enabled J10 Closed Turbo switch disabled J10 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 8MB (4) 1M x 9 (4) 1M x 9 16MB (4) 4M x 9 NONE 20MB (4) 1M x 9 (4) 4M x 9 32MB (4) 4M x 9 (4) 4M x 9 CACHE CONFIGURATION Size Bank 0 (U26 Bank 1 (U22 - Tag Dirty Bit - 29) U25) 32KB (4) 8K x 8 NONE 8K x 8 16K x 4 64KB (4) 8K x 8 (4) 8K x 8 8K x 8 16K x 4 128KB (4) 32K x 8 NONE 32K x 8 16K x 4 256KB (4) 32K x 8 (4) 32K x 8 32K x 8 16K x 4 CACHE JUMPER CONFIGURATION Size J11 J12 J13 J14 J15 J16 J17 J18 J19 32KB 1 & Open 1 & 1 & 1 & 1 & 1 & 1 & 1 & 2 2 2 2 2 2 2 2 64KB 2 & Open 1 & 2 & 1 & 1 & 2 & 1 & 1 & 2 3 2 3 2 2 3 2 128KB 1 & 1 & 2 2 & 2 & 2 & 1 & 2 & 2 & 1 & 2 2 3 3 3 2 3 3 256KB 2 & 2 & 3 2 & 2 & 2 & 2 & 2 & 2 & 2 & 3 3 3 3 3 3 3 3 Note:Pins designated should be in the closed position. CPU TYPE CONFIGURATION Type J20 J21 J22 80486SX Closed pins 1 & 2 pins 1 & 2 closed closed 80487SX Closed pins 1 & 2 pins 2 & 3 closed closed 80486DX Open pins 2 & 3 Open closed