(TXT) View Source
       
       # TANDY/RADIO SHACK
       
          MEMORY EXPANSION BOARD (250-4030)
       
          Card Type              Memory                                  
          Maximum Onboard Memory 2MB DRAM                                
          Data Bus               16-bit ISA                              
       
 (IMG) IMG 1
          
       
          +------------------------------------------------------------+
          |                 USER CONFIGURABLE SETTINGS                 |
          |------------------------------------------------------------|
          |                Setting                 | Label | Position  |
          |----------------------------------------+-------+-----------|
          | » | Factory configured - do not alter  | S1/1  |    Off    |
          |---+------------------------------------+-------+-----------|
          | » | Factory configured - do not alter  | S1/7  |    N/A    |
          |---+------------------------------------+-------+-----------|
          | » | Memory in Bank 1 enabled           | S1/8  |    Off    |
          |---+------------------------------------+-------+-----------|
          |   | Memory in Bank 1 disabled          | S1/8  |    On     |
          |------------------------------------------------------------|
          |      Note:Bank 1 should be disabled only if the board      |
          |      number is set to 1.                                   |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                     DRAM CONFIGURATION                     |
          |------------------------------------------------------------|
          |  Size  |    Bank 0    |   Bank 1   |  Bank 2   |  Bank 3   |
          |--------+--------------+------------+-----------+-----------|
          | 512KB  | (18) 256K x  |    None    |   None    |   None    |
          |        |      1       |            |           |           |
          |--------+--------------+------------+-----------+-----------|
          |  1MB   | (18) 256K x  | (18) 256K  |   None    |   None    |
          |        |      1       |    x 1     |           |           |
          |--------+--------------+------------+-----------+-----------|
          | 1.5MB  | (18) 256K x  | (18) 256K  | (18) 256K |   None    |
          |        |      1       |    x 1     |    x 1    |           |
          |--------+--------------+------------+-----------+-----------|
          |  2MB   | (18) 256K x  | (18) 256K  | (18) 256K | (18) 256K |
          |        |      1       |    x 1     |    x 1    |    x 1    |
          |------------------------------------------------------------|
          |      Note:The exact location of each bank is unidentified. |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                   DRAM JUMPER SELECTION                    |
          |------------------------------------------------------------|
          |         Size          |       S1/5       |      S1/6       |
          |-----------------------+------------------+-----------------|
          |   |       512KB       |        On        |       On        |
          |---+-------------------+------------------+-----------------|
          | » |        1MB        |       Off        |       On        |
          |---+-------------------+------------------+-----------------|
          |   |       1.5MB       |        On        |       Off       |
          |---+-------------------+------------------+-----------------|
          |   |        2MB        |       Off        |       Off       |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                   BOARD NUMBER SELECTION                   |
          |------------------------------------------------------------|
          |   Number    |  Address   |   S1/2    |   S1/3   |   S1/4   |
          |-------------+------------+-----------+----------+----------|
          | »  |   1    |  100000h   |    On     |    On    |    On    |
          |----+--------+------------+-----------+----------+----------|
          |    |   2    |  300000h   |    Off    |    On    |    On    |
          |----+--------+------------+-----------+----------+----------|
          |    |   3    |  500000h   |    On     |   Off    |    On    |
          |----+--------+------------+-----------+----------+----------|
          |    |   4    |  700000h   |    Off    |   Off    |    On    |
          |----+--------+------------+-----------+----------+----------|
          |    |   5    |  900000h   |    On     |    On    |   Off    |
          |----+--------+------------+-----------+----------+----------|
          |    |   6    |  B00000h   |    Off    |    On    |   Off    |
          |----+--------+------------+-----------+----------+----------|
          |    |   7    |  D00000h   |    On     |   Off    |   Off    |
          +------------------------------------------------------------+