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# TANDY/RADIO SHACK
EGA/CGA GRAPHICS BOARD (250-3048A)
Card Type Video card
Video Processor 6845
Maximum Onboard Memory 256KB DRAM
Data Bus 8-bit ISA
Video Types Supported EGA
Highest Resolution Supported 720 x 350
IMG IMG 1
+------------------------------------------------------------+
| CONNECTIONS |
|------------------------------------------------------------|
| Function | Label |
|-------------------------------+----------------------------|
| 9-pin video out | CN1 |
+------------------------------------------------------------+
+------------------------------------------------------------+
| USER CONFIGURABLE SETTINGS |
|------------------------------------------------------------|
| Setting | Label | Position |
|----------------------------------------+-------+-----------|
| » | EGA mode base I/O address set to | P3/A | Pins 1 & |
| | 3D0h | | 2 closed |
|---+------------------------------------+-------+-----------|
| | EGA mode base I/O address set to | P3/A | Pins 2 & |
| | 2D0h | | 3 closed |
|---+------------------------------------+-------+-----------|
| » | Card is installed in normal slot | P3/C | Pins 2 & |
| | | | 3 closed |
|---+------------------------------------+-------+-----------|
| | Card is installed in XT slot 8 | P3/C | Pins 1 & |
| | | | 2 closed |
|---+------------------------------------+-------+-----------|
| » | Factory configured - do not alter | SW1/7 | Off |
|---+------------------------------------+-------+-----------|
| » | Factory configured - do not alter | SW1/8 | Off |
+------------------------------------------------------------+
+------------------------------------------------------------+
| MONITOR TYPE SELECTION |
|------------------------------------------------------------|
| Primary | Secondary | P1 |SW1/1|SW1/2|SW1/3|SW1/4|
| monitor | monitor | | | | | |
|-----------+---------------+--------+-----+-----+-----+-----|
|Lo-res CGA | Monochrome |Pins 2 &| On | Off | Off | On |
| | | 3 | | | | |
|-----------+---------------+--------+-----+-----+-----+-----|
|Hi-res CGA | Monochrome |Pins 2 &| Off | Off | Off | On |
| | | 3 | | | | |
|-----------+---------------+--------+-----+-----+-----+-----|
|Lo-res EGA | Monochrome |Pins 1 &| On | On | On | Off |
| | | 2 | | | | |
|-----------+---------------+--------+-----+-----+-----+-----|
|Hi-res EGA | Monochrome |Pins 1 &| Off | On | On | Off |
| | | 2 | | | | |
|-----------+---------------+--------+-----+-----+-----+-----|
|Monochrome | Lo-res CGA |Pins 2 &| On | Off | On | Off |
| | | 3 | | | | |
|-----------+---------------+--------+-----+-----+-----+-----|
|Monochrome | Hi-res CGA |Pins 2 &| Off | Off | On | Off |
| | | 3 | | | | |
|------------------------------------------------------------|
| Note:Pins designated are in the closed position. |
+------------------------------------------------------------+
+------------------------------------------------------------+
| VIDEO MODE SELECTION |
|------------------------------------------------------------|
| Setting | SW1/5 | SW1/6 |
|--------------------+-------------------+-------------------|
| Monochrome | Off | On |
|--------------------+-------------------+-------------------|
| CGA | On | Off |
|--------------------+-------------------+-------------------|
| EGA | On | On |
+------------------------------------------------------------+
+------------------------------------------------------------+
| AUTOMODE CONFIGURATION |
|------------------------------------------------------------|
| Setting | P3/B | P3/D |
|------------------+--------------------+--------------------|
| » | Enabled | Pins 2 & 3 closed | Pins 1 & 2 closed |
|---+--------------+--------------------+--------------------|
| | Disabled | Pins 1 & 2 closed | Pins 2 & 3 closed |
+------------------------------------------------------------+