TANDY/RADIO SHACK
4025 LX (250-5125), 4033 LX
Processor |
80386 |
Processor Speed |
25MHz |
Chip Set |
Unidentified |
Video Chip Set |
None |
Maximum Onboard Memory |
16MB (on external memory cards) |
Maximum Video Memory |
None |
Cache |
32KB |
BIOS |
Unidentified |
Dimensions |
355mm x 304mm |
I/O Options |
External memory cards (2) CPU slot, floppy drive interface, IDE interface, parallel port, PS/2 mouse port, serial port |
NPU Options |
80387/3167 |
CONNECTIONS | |||
Purpose |
Location |
Purpose |
Location |
PS/2 mouse port |
CN1 |
External battery |
CN6 |
Serial port |
CN2 |
Speaker |
CN7 |
Parallel port |
CN3 |
External memory cards |
SL1 & SL2 |
IDE interface |
CN4 |
CPU slot |
SL3 |
Floppy drive interface |
CN5 |
USER CONFIGURABLE SETTINGS | |||
Function |
Label |
Position | |
» |
Monitor type select through software |
J1 |
Pins 2 & 3 closed |
Monitor type select color |
J1 |
Pins 1 & 2 closed | |
Monitor type select monochrome |
J1 |
Open | |
» |
IDE IOCHRDY enabled |
J4 |
Closed |
IDE IOCHRDY disabled |
J4 |
Open | |
» |
IDE DIAG normal operation |
J5 |
Open |
IDE DIAG diagnostic mode |
J5 |
Closed | |
» |
I/O recovery mode enabled |
J6 |
Closed |
I/O recovery mode disabled |
J6 |
Open | |
» |
Factory configured - do not alter |
J7 |
Closed |
» |
Factory configured - do not alter |
J8 |
Closed |
» |
Factory configured - do not alter |
J9 |
Closed |
DRAM CONFIGURATION | ||||
Size |
Bank 0 |
Bank 1 |
Bank 2 |
Bank 3 |
1MB |
(4) 256K x 9 |
None |
None |
None |
2MB |
(4) 256K x 9 |
(4) 256K x 9 |
None |
None |
4MB |
(4) 1M x 9 |
None |
None |
None |
8MB |
(4) 1M x 9 |
(4) 1M x 9 |
None |
None |
4MB |
(4) 256K x 9 |
(4) 256K x 9 |
(4) 256K x 9 |
(4) 256K x 9 |
10MB |
(4) 1M x 9 |
(4) 1M x 9 |
(4) 256K x 9 |
(4) 256K x 9 |
16MB |
(4) 1M x 9 |
(4) 1M x 9 |
(4) 1M x 9 |
(4) 1M x 9 |
Note: Banks 0 & 1 are located on the first memory card and banks 2 & 3 are located on the second memory card. |
CACHE CONFIGURATION |
Note: The location of the 32KB cache is unidentified. |
BIOS SELECTION | |||
Setting |
J2 |
J3 | |
27128 |
Open |
Open | |
» |
27256 |
Closed |
Closed |
27512 |
Open |
Closed |
MISCELLANEOUS TECHNICAL NOTE |
Jumpers are labeled for information and location purposes only. The purpose of SL4 is unidentified. |