UNIDENTIFIED
TURBO MAIN BOARD (426A)
|
Processor |
8088 |
|
Processor Speed |
4.77/8MHz |
|
Chip Set |
Unidentified |
|
Video Chip Set |
None |
|
Maximum Onboard Memory |
640KB |
|
Maximum Video Memory |
None |
|
Cache |
None |
|
BIOS |
Unidentified |
|
Dimensions |
330mm x 218mm |
|
I/O Options |
None |
|
NPU Options |
8087 |
|
CONNECTIONS | |||
|
Purpose |
Location |
Purpose |
Location |
|
Turbo switch (to turbo switch button) |
JP5 |
Power LED |
JP9 pins 3 & 4 |
|
Turbo LED |
JP9 pins 1 & 2 |
Speaker |
P4 |
|
USER CONFIGURABLE SETTINGS | |||
|
Function |
Label |
Position | |
|
|
Factory configured - do not alter |
JP1 |
Unidentified |
|
Turbo enabled |
JP6 |
Closed | |
|
Turbo disabled |
JP6 |
Open | |
|
Turbo enabled (CTRL, ALT, +) |
JP7 |
Closed | |
|
Turbo disabled (CTRL, ALT, -) |
JP7 |
Open | |
|
Keyboard lock disabled |
JP8 |
Closed | |
|
Keyboard lock enabled |
JP8 |
Open | |
|
|
Factory configured - do not alter |
SW1/1 |
Off |
|
NPU not installed |
SW1/2 |
On | |
|
NPU installed |
SW1/2 |
Off | |
|
Note: JP6 is for turbo selectable through hardware. JP7 is for turbo selectable through software. Both jumpers cannot be closed at the same time. | |||
|
DRAM CONFIGURATION | ||||
|
Size |
Bank 0 |
Bank 1 |
Bank 2 |
Bank 3 |
|
256KB (A) |
(9) 4164 |
(9) 4164 |
(9) 4164 |
(9) 4164 |
|
256KB (B) |
(9) 41256 |
None |
None |
None |
|
512KB |
(9) 41256 |
(9) 41256 |
None |
None |
|
640KB |
(9) 41256 |
(9) 41256 |
(9) 4164 |
(9) 4164 |
|
Note: The location of banks 0, 1, 2, & 3 are unidentified. | ||||
|
DRAM JUMPER CONFIGURATION | ||
|
Size |
JP3 |
JP4 |
|
256KB (A) |
Pins 1 & 3, 5 & 7 closed |
Pins 2 & 4 closed |
|
256KB (B) |
Pins 2 & 4, 6 & 8 closed |
Pins 1 & 3 closed |
|
512KB |
Pins 2 & 4, 6 & 8 closed |
Pins 1 & 3 closed |
|
640KB |
Pins 2 & 4, 6 & 8 closed |
Pins 1 & 3 closed |
|
DRAM SWITCH CONFIGURATION | ||
|
Size |
SW1/3 |
SW1/4 |
|
128KB |
Off |
On |
|
192KB |
On |
Off |
|
256KB |
Off |
Off |
|
FLOPPY DRIVE SELECTION | ||
|
Drives installed |
SW1/7 |
SW1/8 |
|
1 |
On |
On |
|
2 |
Off |
On |
|
3 |
On |
Off |
|
4 |
Off |
Off |
|
MONITOR SELECTION | ||
|
Type |
SW1/5 |
SW1/6 |
|
None |
On |
On |
|
Color (40 x 20) |
Off |
On |
|
Color (80 x 25) |
On |
Off |
|
Monochrome |
Off |
Off |