I-BUS
ORCA (REV. B)
|
Processor |
CX486/AM486/80486SX/SL80486/80486DX/80486DX4/P24D/P24T |
|
Processor Speed |
25/33/40/50(internal)/50/66(internal)100(internal)MHz |
|
Chip Set |
OPTI |
|
Video Chip Set |
Cirrus Logic |
|
Maximum Onboard Memory |
128MB |
|
Maximum Video Memory |
2MB |
|
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 |
|
CONNECTIONS | |||
|
Purpose |
Location |
Purpose |
Location |
|
IDE interface |
J2 |
Auxiliary keyboard connector |
J14 |
|
Floppy drive interface |
J3 |
PS/2 mouse port |
J21 |
|
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 alter |
J12 |
Open |
|
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 alter |
J38 |
Unidentified |
|
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 36 |
(1) 16M x 36 |
None |
None |
|
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 closed |
Pins 5 & 6 closed |
|
33MHz |
Pins 1 & 3, 4 & 6 closed |
Pins 1 & 2, 5 & 6 closed |
|
40MHz |
Pins 2 & 4, 3 & 5 closed |
Pins 3 & 4, 5 & 6 closed |
|
50iMHz |
Pins 1 & 3, 2 & 4 closed |
Pins 5 & 6 closed |
|
50MHz |
Pins 3 & 5, 4 & 6 closed |
Pins 1 & 2, 3 & 4, 5 & 6 closed |
|
66iMHz |
Pins 1 & 3, 4 & 6 closed |
Pins 1 & 2, 5 & 6 closed |
|
100iMHz |
Pins 1 & 3, 4 & 6 closed |
Pins 1 & 2, 5 & 6 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 |