YOUNG MICRO SYSTEMS, INC. 486 EISA/VESA Processor 80486SX/80486DX/80486DX2/Pentium Overdrive Processor Speed 20/25/33/40/50/50(internal)/66(internal)/MHz Chip Set VIA Max. Onboard DRAM64MB Cache 64/128/256/512/1024KB BIOS AMI Dimensions 330mm x 218mm I/O Options 32-bit VESA local bus slots (3) NPU Options None [Image] CONNECTIONS Purpose Location Purpose Location Reset switch CN1 Turbo LED CN4 Power LED & keylock CN2 Turbo switch CN5 Speaker CN3 32 bit VESA local SL1, SL2, SL3 bus slots USER CONFIGURABLE SETTINGS Function Jumper Position » Factory configured - do not alter J1 pins 1 & 2 closed » Fastgate A20 enabled J2 pins 1 & 2 closed Fastgate A20 disabled J2 pins 2 & 3 closed » One or more ISA busmastering J10 pins 1 & 2 devices on ISA bus closed ISA busmastering system free J10 pins 2 & 3 closed » Normal BIOS type operation JP20 pins 1 & 2 closed Flash EPROM type BIOS enabled JP20 pins 2 & 3 closed » Graphic accelerator cards without JP21 pins 1 & 2 Weitek P9x00 closed Graphic accelerator card with JP21 pins 2 & 3 Weitek P9x00 closed DRAM CONFIGURATION Size Bank 0 Bank 1 Bank 2 Bank 3 1MB (1) 256K x NONE NONE NONE 36 2MB (1) 512K x NONE NONE NONE 36 2MB (1) 256K x (1) 256K x NONE NONE 36 36 4MB (1) 1M x 36 NONE NONE NONE 4MB (1) 512K x NONE (1) 512K x NONE 36 36 8MB (1) 2M x 36 NONE NONE NONE 8MB (1) 1M x 36 (1) 1M x 36 NONE NONE 16MB (1) 4M x 36 NONE NONE NONE 16MB (1) 2M x 36 NONE (1) 2M x 36 NONE 32MB (1) 8M x 36 NONE NONE NONE 32MB (1) 4M x 36 NONE (1) 4M x 36 NONE 64MB (1) 8M x 36 NONE (1) 8M x 36 NONE 64MB (1) 4M x 36 (1) 4M x 36 (1) 4M x 36 (1) 4M x 36 CACHE CONFIGURATION (WRITE-THROUGH CACHE) Size Bank 0 Bank 1 WTTAG WBTAG 64KB (4) 8K x 8 (4) 8K x 8 NONE (1) 8K x 8 128KB (4) 32K x 8 NONE NONE (1) 32K x 8 256KB (4) 32K x 8 (4) 32K x 8 NONE (1) 32K x 8 512KB (4) 128K x NONE NONE (1) 32K x 8 8 1M (4) 128K x (4) 128K x NONE (1) 128K x 8 8 8 CACHE CONFIGURATION (WRITE-BACK CACHE) Size Bank 0 Bank 1 WTTAG WBTAG 64KB (4) 8K x 8 (4) 8K x 8 (1) 8K x 8 (1) 8K x 8 128KB (4) 32K x 8 NONE (1) 32K x 8 (1) 32K x 8 256KB (4) 32K x 8 (4) 32K x 8 (1) 32K x 8 (1) 32K x 8 512KB (4) 128K x NONE (1) 32K x 8 (1) 32K x 8 8 1M (4) 128K x (4) 128K x (1) 128K x (1) 128K x 8 8 8 8 CACHE JUMPER CONFIGURATION Size JS1 JS2 JS3 JS4 JS5 JS6 64KB 1 & 2 1 & 2 1 & 2 1 & 2 1 & 2 1 & 2 128KB 2 & 3 2 & 3 1 & 2 1 & 2 1 & 2 1 & 2 256KB 2 & 3 2 & 3 2 & 3 1 & 2 1 & 2 1 & 2 512KB 2 & 3 2 & 3 2 & 3 2 & 3 2 & 3 1 & 2 1MB 2 & 3 2 & 3 2 & 3 2 & 3 2 & 3 2 & 3 Note:Pins designated should be in the closed position. CPU TYPE CONFIGURATION CPU Type Speed JC1 JC2 JC3 JK1 JK2 80486SX 20MHz 2 & 3 2 & 3 Open 1 & 2 1 & 2 80486SX 25MHz 2 & 3 2 & 3 Open 1 & 2 1 & 2 80486SX 33MHz 2 & 3 2 & 3 Open 1 & 2 1 & 2 80487SX 25MHz 1 & 2 1 & 2 2 & 3 1 & 2 1 & 2 80486DX 25MHz 1 & 2 1 & 2 1 & 2 1 & 2 1 & 2 80486DX 33MHz 1 & 2 1 & 2 1 & 2 1 & 2 1 & 2 80486DX 40MHz 1 & 2 1 & 2 1 & 2 1 & 2 1 & 2 80486DX 50MHz 1 & 2 1 & 2 1 & 2 2 & 3 2 & 3 80486DX2 50iMHz 1 & 2 1 & 2 1 & 2 1 & 2 1 & 2 80486DX2 66iMHz 1 & 2 1 & 2 2 & 3 1 & 2 1 & 2 Note:Pins designated should be in the closed position. CPU TYPE CONFIGURATION (CON’T) CPU Type Speed JV1 JV2 JK3A1 JK3B1 80486SX 20MHz 2 & 3 1 & 2 Closed Closed 80486SX 25MHz 2 & 3 1 & 2 Open Closed 80486SX 33MHz 2 & 3 1 & 2 Closed Open 80487SX 25MHz 2 & 3 1 & 2 Open Closed 80486DX 25MHz 2 & 3 1 & 2 Open Closed 80486DX 33MHz 2 & 3 2 & 3 Closed Open 80486DX 40MHz 2 & 3 2 & 3 Open Open 80486DX 50MHz 2 & 3 1 & 2 Open Closed 80486DX2 50iMHz 2 & 3 1 & 2 Open Open 80486DX2 66iMHz 2 & 3 1 & 2 Closed Closed Note:Pins designated should be in the closed position.