I-BUS ORCA (REV. B) Processor CX486/AM486/80486SX/SL80486/80486DX/80486DX4/P24D/P24T Processor 25/33/40/50(internal)/50/66(internal)100(internal)MHz Speed Chip Set OPTI Video Chip Cirrus Logic Set Maximum 128MB Onboard Memory Maximum Video 2MB Memory Cache 64/128/256/512KB BIOS Unidentified Dimensions Unidentified I/O Options Floppy drive interface, IDE interface, parallel port, PS/2 mouse port, serial ports (2), VGA port NPU Options None [Image] CONNECTIONS Purpose Location Purpose Location IDE interface J2 Auxiliary keyboard J14 connector Floppy drive J3 PS/2 mouse port J21 interface Parallel port J4 Reset switch J22 Serial port 1 J5 Speaker J25 Serial port 2 J6 Chassis fan power J26 IDE interface LED J9 VGA port J33 USER CONFIGURABLE SETTINGS Function Label Position IDE IRQ14 enabled J1 Closed IDE IRQ14 disabled J1 Open IDE read prefetch enabled J8 Pins 1 & 2 closed IDE read prefetch disabled J8 Pins 2 & 3 closed IDE type select primary J11 Pins 1 & 3 closed IDE type select secondary J11 Pins 3 & 5 closed IDE interface enabled J11 Pins 2 & 4 closed IDE interface disabled J11 Pins 4 & 6 closed » Factory configured - do not J12 Open alter Floppy drive select 1.44MB J13 Pins 1 & 2 closed Floppy drive select 2.88MB J13 Pins 3 & 4, 5 & 6 closed » CMOS memory normal operation J17 Pins 2 & 3 closed CMOS memory clear J17 Pins 1 & 2 closed PS/2 mouse IRQ12 enabled J18 Closed PS/2 mouse IRQ12 disabled J18 Open Password enabled J19 Closed Password disabled J19 Open Video IRQ9 enabled J31 Closed Video IRQ9 disabled J31 Open » Factory configured - do not J38 Unidentified alter DRAM CONFIGURATION Size Bank 0 Bank 1 Bank 2 Bank 3 4MB (1) 1M x 36 None None None 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 (1) 2M x 36 None None 16MB (1) 1M x 36 (1) 1M x 36 (1) 1M x 36 (1) 1M x 36 24MB (1) 2M x 36 (1) 2M x 36 (1) 1M x 36 (1) 1M x 36 32MB (1) 8M x 36 None None None 32MB (1) 4M x 36 (1) 4M x 36 None None 32MB (1) 2M x 36 (1) 2M x 36 (1) 2M x 36 (1) 2M x 36 40MB (1) 4M x 36 (1) 4M x 36 (1) 1M x 36 (1) 1M x 36 48MB (1) 4M x 36 (1) 4M x 36 (1) 2M x 36 (1) 2M x 36 64MB (1) 8M x 36 (1) 8M x 36 None None 64MB (1) 4M x 36 (1) 4M x 36 (1) 4M x 36 (1) 4M x 36 72MB (1) 8M x 36 (1) 8M x 36 (1) 1M x 36 (1) 1M x 36 80MB (1) 8M x 36 (1) 8M x 36 (1) 2M x 36 (1) 2M x 36 96MB (1) 8M x 36 (1) 8M x 36 (1) 4M x 36 (1) 4M x 36 128MB (1) 16M x (1) 16M x None None 36 36 128MB (1) 8M x 36 (1) 8M x 36 (1) 8M x 36 (1) 8M x 36 CACHE CONFIGURATION Note: Board accepts 64KB/128KB/256KB/512KB cache. The location of banks 0 & 1 is unidentified. CACHE JUMPER CONFIGURATION Size J15 64KB Open 128KB Pins 5 & 6 closed 256KB Pins 3 & 4, 5 & 6 closed 512KB Pins 1 & 2, 3 & 4, 5 & 6 closed CACHE BANK CONFIGURATION Setting J16 Single bank Pins 1 & 2 closed Dual banks Pins 2 & 3 closed VIDEO MEMORY CONFIGURATION Note: Board accepts up to 2MB of video memory. The location and chip sizes are unidentified. CPU SPEED SELECTION Speed J7 J28 25MHz Pins 1 & 3, 2 & 4 Pins 5 & 6 closed closed 33MHz Pins 1 & 3, 4 & 6 Pins 1 & 2, 5 & 6 closed closed 40MHz Pins 2 & 4, 3 & 5 Pins 3 & 4, 5 & 6 closed closed 50iMHz Pins 1 & 3, 2 & 4 Pins 5 & 6 closed closed 50MHz Pins 3 & 5, 4 & 6 Pins 1 & 2, 3 & 4, 5 & closed 6 closed 66iMHz Pins 1 & 3, 4 & 6 Pins 1 & 2, 5 & 6 closed closed 100iMHz Pins 1 & 3, 4 & 6 Pins 1 & 2, 5 & 6 closed closed CPU TYPE SELECTION Type J29 J37 Cyrix Pins 2 & 3 closed Pins 1 & 2, 3 & 4 closed AMD Pins 1 & 2 closed Open Intel Pins 1 & 2 closed Open CPU TYPE SELECTION Type J36 Intel SX Pins 2 & 3 closed Intel DX Pins 1 & 2, 3 & 4 closed CPU TYPE SELECTION Type J24 SL80486 Pins 1 & 2, 3 & 4 closed P24T burst Pins 5 & 6 closed P24T WB Pins 7 & 8 closed P24T WT Open CPU TYPE SELECTION Type J34 Cyrix Pins 4 & 6 closed SL80486 Pins 2 & 4 closed P24D WB Pins 3 & 5 closed P24D WT Pins 1 & 3 closed CPU TYPE SELECTION Type J35 All CPU types Pins 1 & 3 closed P24T only Pins 3 & 5 closed Bit 0 to stop clock Pins 2 & 4 closed Bit 1 to stop clock Pins 4 & 6 closed CPU MULTIPLIER SELECTION Multiplier J23 Cyrix CPU Pins 3 & 4 closed 2x Pins 3 & 5 closed 2.5x Pins 1 & 3 closed 3x Open CPU FREQUENCY SELECTION Speed J27 8MHz Pins 1 & 2 closed 16MHz (DX4) Pins 2 & 3 closed DMA CHANNEL SELECTION Channel J32 1 Pins 3 & 4, 5 & 6 closed 3 Pins 1 & 2, 7 & 8 closed IDE MODE SELECTION Speed J10 180ns Pins 1 & 3, 2 & 4 closed 240ns Pins 3 & 5, 2 & 4 closed 383ns Pins 1 & 3, 4 & 6 closed 480ns Pins 3 & 5, 4 & 6 closed ON BOARD VIDEO SELECTION Setting J30 J39 Enabled Pins 2 & 3 closed Closed Disabled Pins 1 & 2 closed Open