(TXT) View Source
       
       # MYLEX CORPORATION
       
          MSI/MDI486 System Board
       
          Processor        80486SX/80487SX/80486DX                       
          Processor Speed  20/25/33MHz                                   
          Chip Set         OPTI                                          
          Max. Onboard     32MB                                          
          DRAM             
          Cache            64/256KB                                      
          BIOS             Mylex                                         
          Dimensions       330mm x 218mm                                 
          I/O Options      Floppy drive interface, IDE interface,        
                           parallel port, serial ports (2)               
          NPU Options      4167                                          
       
 (IMG) IMG 1
          
       
          +------------------------------------------------------------+
          |                        CONNECTIONS                         |
          |------------------------------------------------------------|
          | Purpose             | Location | Purpose        | Location |
          |---------------------+----------+----------------+----------|
          | External battery    |   BAT    | Turbo LED      |   JP3    |
          |---------------------+----------+----------------+----------|
          | Serial port 2       |   COM2   | Reset switch   |   JP4    |
          |---------------------+----------+----------------+----------|
          | Serial port 1       |   COM1   | Speaker        |   JP5    |
          |---------------------+----------+----------------+----------|
          | Floppy drive        |   FDD    | IDE interface  |   JP6    |
          | interface           |          | LED            |          |
          |---------------------+----------+----------------+----------|
          | IDE interface       |   IDE    | Parallel port  |   LPT    |
          |---------------------+----------+----------------+----------|
          | Power LED & keylock |   JP2    |                |          |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                 USER CONFIGURABLE SETTINGS                 |
          |------------------------------------------------------------|
          |               Function               | Jumper |  Position  |
          |--------------------------------------+--------+------------|
          | » | Monitor type select color        |  JP1   |   Closed   |
          |---+----------------------------------+--------+------------|
          |   | Monitor type select monochrome   |  JP1   |    Open    |
          |---+----------------------------------+--------+------------|
          | » | Parallel port select LPT1        |  JP19  | pins 2 & 3 |
          |   | interrupt IRQ7                   |        |   closed   |
          |---+----------------------------------+--------+------------|
          |   | Parallel port select LPT2        |  JP19  | pins 1 & 2 |
          |   | interrupt IRQ5                   |        |   closed   |
          |---+----------------------------------+--------+------------|
          | » | On-board interface ports enabled |  JP20  | pins 1 & 2 |
          |   |                                  |        |   closed   |
          |---+----------------------------------+--------+------------|
          |   | On-board interface ports         |  JP20  | pins 2 & 3 |
          |   | disabled                         |        |   closed   |
          |---+----------------------------------+--------+------------|
          | » | Battery type select internal     |  JP21  | pins 2 & 3 |
          |   |                                  |        |   closed   |
          |---+----------------------------------+--------+------------|
          |   | Battery type select external     |  JP21  |    Open    |
          |---+----------------------------------+--------+------------|
          |   | CMOS memory clear                |  JP21  | pins 1 & 2 |
          |   |                                  |        |   closed   |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                     DRAM CONFIGURATION                     |
          |------------------------------------------------------------|
          |       Size       |       Bank 0       |       Bank 1       |
          |------------------+--------------------+--------------------|
          |       1MB        |    (4) 256K x 9    |        NONE        |
          |------------------+--------------------+--------------------|
          |       2MB        |    (4) 256K x 9    |    (4) 256K x 9    |
          |------------------+--------------------+--------------------|
          |       4MB        |     (4) 1M x 9     |        NONE        |
          |------------------+--------------------+--------------------|
          |       5MB        |     (4) 1M x 9     |    (4) 256K x 9    |
          |------------------+--------------------+--------------------|
          |       8MB        |     (4) 1M x 9     |     (4) 1M x 9     |
          |------------------+--------------------+--------------------|
          |       16MB       |     (4) 4M x 9     |        NONE        |
          |------------------+--------------------+--------------------|
          |       17MB       |     (4) 4M x 9     |    (4) 256K x 9    |
          |------------------+--------------------+--------------------|
          |       20MB       |     (4) 4M x 9     |     (4) 1M x 9     |
          |------------------+--------------------+--------------------|
          |       32MB       |     (4) 4M x 9     |     (4) 4M x 9     |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                    CACHE CONFIGURATION                     |
          |------------------------------------------------------------|
          |    Size    |    Bank 0     |   TAG (U19)   |   TAG (U20)   |
          |------------+---------------+---------------+---------------|
          |    64KB    |  (8) 8K x 8   |  (1) 8K x 8   |  (1) 64K x 1  |
          |------------+---------------+---------------+---------------|
          |   256KB    |  (8) 32K x 8  |  (1) 32K x 8  |  (1) 64K x 1  |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                 CACHE JUMPER CONFIGURATION                 |
          |------------------------------------------------------------|
          |   Size    |    JP7     |    JP11    |   JP12   |   JP13    |
          |-----------+------------+------------+----------+-----------|
          |   64KB    |    Open    |    Open    |   Open   |   Open    |
          |-----------+------------+------------+----------+-----------|
          |   256KB   |   Closed   |   Closed   |   Open   |  Closed   |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                   CPU TYPE CONFIGURATION                   |
          |------------------------------------------------------------|
          |   Type   |        JP8        |        JP9        |  JP10   |
          |----------+-------------------+-------------------+---------|
          | 80486SX  |       Open        | pins 2 & 3 closed |  Open   |
          |----------+-------------------+-------------------+---------|
          | 80487SX  | pins 2 & 3 closed | pins 1 & 2 closed | Closed  |
          |----------+-------------------+-------------------+---------|
          | 80486DX  | pins 1 & 2 closed | pins 1 & 2 closed | Closed  |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                  CPU SPEED CONFIGURATION                   |
          |------------------------------------------------------------|
          | Speed |    JP14     |    JP15    |    JP16    |    JP17    |
          |-------+-------------+------------+------------+------------|
          | 20MHz | pins 2 & 3  | pins 1 & 2 | pins 2 & 3 | pins 1 & 2 |
          |       |   closed    |   closed   |   closed   |   closed   |
          |-------+-------------+------------+------------+------------|
          | 25MHz | pins 2 & 3  | pins 2 & 3 | pins 1 & 2 | pins 2 & 3 |
          |       |   closed    |   closed   |   closed   |   closed   |
          |-------+-------------+------------+------------+------------|
          | 33MHz | pins 2 & 3  | pins 1 & 2 | pins 1 & 2 | pins 2 & 3 |
          |       |   closed    |   closed   |   closed   |   closed   |
          +------------------------------------------------------------+