TEXT View Source
# 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 2MB
Video
Memory
Cache 64/128/256/512KB
BIOS Unidentified
Dimensions Unidentified
I/O Floppy drive interface, IDE interface, parallel port,
Options PS/2 mouse port, serial ports (2), VGA port
NPU None
Options
IMG IMG 1
+------------------------------------------------------------+
| CONNECTIONS |
|------------------------------------------------------------|
| Purpose | Location | Purpose | Location |
|-------------------+----------+------------------+----------|
| IDE interface | J2 | Auxiliary | J14 |
| | | keyboard | |
| | | 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 | J26 |
| | | power | |
|-------------------+----------+------------------+----------|
| 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 | None | None |
| | | 36 | | |
|-------+-------------+------------+------------+------------|
| 16MB | (1) 4M x 36 | None | None | None |
|-------+-------------+------------+------------+------------|
| 16MB | (1) 2M x 36 | (1) 2M x | None | None |
| | | 36 | | |
|-------+-------------+------------+------------+------------|
| 16MB | (1) 1M x 36 | (1) 1M x | (1) 1M x | (1) 1M x |
| | | 36 | 36 | 36 |
|-------+-------------+------------+------------+------------|
| 24MB | (1) 2M x 36 | (1) 2M x | (1) 1M x | (1) 1M x |
| | | 36 | 36 | 36 |
|-------+-------------+------------+------------+------------|
| 32MB | (1) 8M x 36 | None | None | None |
|-------+-------------+------------+------------+------------|
| 32MB | (1) 4M x 36 | (1) 4M x | None | None |
| | | 36 | | |
|-------+-------------+------------+------------+------------|
| 32MB | (1) 2M x 36 | (1) 2M x | (1) 2M x | (1) 2M x |
| | | 36 | 36 | 36 |
|-------+-------------+------------+------------+------------|
| 40MB | (1) 4M x 36 | (1) 4M x | (1) 1M x | (1) 1M x |
| | | 36 | 36 | 36 |
|-------+-------------+------------+------------+------------|
| 48MB | (1) 4M x 36 | (1) 4M x | (1) 2M x | (1) 2M x |
| | | 36 | 36 | 36 |
|-------+-------------+------------+------------+------------|
| 64MB | (1) 8M x 36 | (1) 8M x | None | None |
| | | 36 | | |
|-------+-------------+------------+------------+------------|
| 64MB | (1) 4M x 36 | (1) 4M x | (1) 4M x | (1) 4M x |
| | | 36 | 36 | 36 |
|-------+-------------+------------+------------+------------|
| 72MB | (1) 8M x 36 | (1) 8M x | (1) 1M x | (1) 1M x |
| | | 36 | 36 | 36 |
|-------+-------------+------------+------------+------------|
| 80MB | (1) 8M x 36 | (1) 8M x | (1) 2M x | (1) 2M x |
| | | 36 | 36 | 36 |
|-------+-------------+------------+------------+------------|
| 96MB | (1) 8M x 36 | (1) 8M x | (1) 4M x | (1) 4M x |
| | | 36 | 36 | 36 |
|-------+-------------+------------+------------+------------|
| 128MB | (1) 16M x | (1) 16M x | None | None |
| | 36 | 36 | | |
|-------+-------------+------------+------------+------------|
| 128MB | (1) 8M x 36 | (1) 8M x | (1) 8M x | (1) 8M x |
| | | 36 | 36 | 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 & 6 |
| | closed | 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 |
+------------------------------------------------------------+