TEXT View Source
# TANDY/RADIO SHACK
4025 LX (250-5125), 4033 LX
Processor 80386
Processor Speed 25MHz
Chip Set Unidentified
Video Chip Set None
Maximum Onboard 16MB (on external memory cards)
Memory
Maximum Video None
Memory
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
IMG IMG 1
+------------------------------------------------------------+
| CONNECTIONS |
|------------------------------------------------------------|
| Purpose | Location | Purpose | Location |
|-------------------+----------+------------------+----------|
| PS/2 mouse port | CN1 | External battery | CN6 |
|-------------------+----------+------------------+----------|
| Serial port | CN2 | Speaker | CN7 |
|-------------------+----------+------------------+----------|
| Parallel port | CN3 | External memory | SL1 & |
| | | cards | SL2 |
|-------------------+----------+------------------+----------|
| IDE interface | CN4 | CPU slot | SL3 |
|-------------------+----------+------------------+----------|
| Floppy drive | CN5 | | |
| interface | | | |
+------------------------------------------------------------+
+------------------------------------------------------------+
| USER CONFIGURABLE SETTINGS |
|------------------------------------------------------------|
| Function | Label | Position |
|---------------------------------------+-------+------------|
| » | Monitor type select through | J1 | Pins 2 & 3 |
| | software | | 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 | None | None |
| | | x 9 | | |
|---------+--------------+-----------+-----------+-----------|
| 4MB | (4) 1M x 9 | None | None | None |
|---------+--------------+-----------+-----------+-----------|
| 8MB | (4) 1M x 9 | (4) 1M x | None | None |
| | | 9 | | |
|---------+--------------+-----------+-----------+-----------|
| 4MB | (4) 256K x 9 | (4) 256K | (4) 256K | (4) 256K |
| | | x 9 | x 9 | x 9 |
|---------+--------------+-----------+-----------+-----------|
| 10MB | (4) 1M x 9 | (4) 1M x | (4) 256K | (4) 256K |
| | | 9 | x 9 | x 9 |
|---------+--------------+-----------+-----------+-----------|
| 16MB | (4) 1M x 9 | (4) 1M x | (4) 1M x | (4) 1M x |
| | | 9 | 9 | 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. |
+------------------------------------------------------------+