CHAINTECH COMPUTER COMPANY, LTD. 420SXB/425SXB/433SCB/450SCB Processor 80486SX/80487SX/80486DX/ODP486SX/80486DX2 Processor Speed 16/20/25/33/50(internal)/50/66(internal)MHz Chip Set SIS Max. Onboard DRAM32MB Cache 64/128/256KB BIOS AMI Dimensions 330mm x 218mm I/O Options None NPU Options 4167 [Image] CONNECTIONS Purpose Location Purpose Location External battery J1 Speaker J4 Turbo LED J2 Power LED & keylock J5 Turbo switch J3 Reset switch J6 USER CONFIGURABLE SETTINGS Function Jumper Position » Turbo enabled J3 Closed Turbo disabled J3 Open » Monitor type select monochrome J7 Open Monitor type select color J7 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 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 Bank 1 TAG 64KB (4) 8K x 8 (4) 8K x 8 (1) 8K x 8 128KB (4) 32K x 8 NONE (1) 8K x 8 256KB (4) 32K x 8 (4) 32K x 8 (1) 32K x 8 CACHE JUMPER CONFIGURATION Size RN12 RN15 RN16 RN17 RN18 RN19 64KB Installed Installed Not Not Not Not installed installed installed installed 128KB Not Not Not Installed Installed Not installed installed installed installed 256KB Not Not Installed Not Not Installed installed installed installed installed CPU TYPE CONFIGURATION Type JP7 80486SX pins 2 & 3 closed ODP486SX pins 2 & 3 closed 80487SX pins 2 & 3 closed 80486DX pins 1 & 2 closed 80486DX2 pins 1 & 2 closed CPU SPEED CONFIGURATION Speed JP1 16MHz pins 2 & 3 closed 20MHz pins 2 & 3 closed > 25MHz pins 1 & 2 closed MISCELLANEOUS TECHNICAL NOTE Note:If a Weitek coprocessor is desired, the optional daughter board must be installed in CPU socket.