ISA/EISA, INC. 486B Processor 80486SX/80487SX/80486DX Processor Speed 20/33MHz Chip Set OPTI Max. Onboard DRAM 32MB SRAM Cache 64/256KB BIOS AMI Dimensions 330mm x 218mm I/O Options None NPU Options 4167 [Image] CONNECTIONS Purpose Location Purpose Location Power LED & keylock J1 Turbo switch JP2 Speaker J3 Turbo LED JP21 External battery J4 Cooling fan switch JP25 Reset switch JP1 Cooling fan power USP8 USER CONFIGURABLE SETTINGS Function Jumper Position » Factory configured - do not alter JP10 unknown » CPU speed select switchable at JP12 pins 1 & 2 keyboard closed CPU speed select switchable at JP12 pins 2 & 3 turbo switch closed » Factory configured - do not alter JP26 open » Video BIOS shadow before JP27 pins 1 & 2 initialization closed Video BIOS shadow after JP27 pins 2 & 3 initialization closed CPU JUMPER CONFIGURATION CPU JP22 JP23 JP24 80486DX (33MHz) pins 1 & 2 pins 1 & 2 pins 1 & 2 and 3 & closed closed 4 closed 80487SX (20MHz) pins 3 & 4 pins 2 & 3 pins 1 & 2 and 3 & closed closed 4 closed 80486SX (20MHz) pins 2 & 3 pins 2 & 3 pins 2 & 3 closed closed closed 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 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) 4M x 9 (4) 256K x 9 20MB (4) 1M x 9 (4) 4M x 9 20MB (4) 4M x 9 (4) 1M x 9 32MB (4) 4M x 9 (4) 4M x 9 SRAM JUMPER CONFIGURATION Size JP6 JP7 JP8 JP9 JP20 64KB pins 1 & pins 1 & pins 1 & pins 1 & pins 1 & 2 2 2 2 2 256KB pins 2 & pins 2 & pins 2 & pins 2 & pins 1 & 3 3 3 3 2 Disabled N/A N/A N/A N/A pins 2 & 3 Note:Pins designated should be in the closed position. SRAM CONFIGURATION Size Cache SRAM TAG 64KB (8) 8K x 8 (1) 8K x 8 256KB (8) 32K x 8 (1) 32K x 8 I/O BUS SPEED JUMPER CONFIGURATION Bus JP3 JP4 JP5 JP13 JP14 JP15 Speed CPU/8 open open open open open closed CPU/6 open open open open closed open CPU/5 open open open closed open open CPU/4 open open closed open open open CPU/3 open closed open open open open CPU/2 closed open open open open open