COMPUTREND SYSTEMS, INC.
========================

   CONTAQ SINGLE CHIP 486 (MS-4123 Ver. 1.1)

   Processor         80486SX/80487SX/80486DX/ODP486SX/80486DX2    
   Processor Speed   20/25/33/50(internal)/50/66(internal)        
   Chip Set          CONTAQ                                       
   Max. Onboard DRAM 32MB                                         
   SRAM Cache        64/128/256KB                                 
   BIOS              AMI                                          
   Dimensions        250mm x 220mm                                
   I/O Options       32-bit VESA card slots (2), auxiliary        
                     keyboard connector                           
   NPU Options       None                                         

<gopher://bitreich.org/I/th99/m/C-D/31248-1.png>
   

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   | Purpose           | Location | Purpose          | Location |
   |-------------------+----------+------------------+----------|
   | Auxiliary         |    J2    | Turbo switch     | J5/15 -  |
   | keyboard          |          |                  |    17    |
   |-------------------+----------+------------------+----------|
   | Power LED &       | J5/1 - 5 | Turbo LED        |  J5/12   |
   | keylock           |          |                  |   &13    |
   |-------------------+----------+------------------+----------|
   | Speaker           |  J5/7 -  | External battery |    J4    |
   |                   |    10    |                  |          |
   |-------------------+----------+------------------+----------|
   | Reset switch      | J5/19 &  | 32-bit VESA card | S1 & S2  |
   |                   |    20    |                  |          |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 USER CONFIGURABLE SETTINGS                 |
   |------------------------------------------------------------|
   |              Function              | Jumper |   Position   |
   |------------------------------------+--------+--------------|
   |>> | Monitor type select monochrome |  JP1   |     Open     |
   |---+--------------------------------+--------+--------------|
   |   | Monitor type select color      |  JP1   |    Closed    |
   |---+--------------------------------+--------+--------------|
   |   | CPU speed select 20/25MHz      |  JP3   |  pins 2 & 3  |
   |   |                                |        |    closed    |
   |   |                                |  JP13  |              |
   |   |                                |        |     open     |
   |---+--------------------------------+--------+--------------|
   |   | CPU speed select 33MHz         |  JP3   |  pins 1 & 2  |
   |   |                                |        |    closed    |
   |   |                                |  JP13  |              |
   |   |                                |        |     open     |
   |---+--------------------------------+--------+--------------|
   |   | CPU speed select > 33MHz       |  JP3   |  pins 1 & 2  |
   |   |                                |        |    closed    |
   |   |                                |  JP13  |              |
   |   |                                |        |    closed    |
   |---+--------------------------------+--------+--------------|
   |>> | Battery select internal        |   J4   |  pins 2 & 3  |
   |   |                                |        |    closed    |
   |---+--------------------------------+--------+--------------|
   |   | Battery select external        |   J4   |    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) 256K x 9    |     (4) 1M x 9     |
   |------------------+--------------------+--------------------|
   |       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) 256K x 9    |     (4) 4M x 9     |
   |------------------+--------------------+--------------------|
   |       17MB       |     (4) 4M x 9     |    (4) 256K x 9    |
   |------------------+--------------------+--------------------|
   |       20MB       |     (4) 1M x 9     |     (4) 4M x 9     |
   |------------------+--------------------+--------------------|
   |       20MB       |     (4) 4M x 9     |     (4) 1M x 9     |
   |------------------+--------------------+--------------------|
   |       32MB       |     (4) 4M x 9     |     (4) 4M x 9     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                  CPU JUMPER CONFIGURATION                  |
   |------------------------------------------------------------|
   |          CPU           |                JP6                |
   |------------------------+-----------------------------------|
   |        80486DX2        | pins 1 & 2, 4 & 5, 8 & 9, 11 & 12 |
   |------------------------+-----------------------------------|
   |        ODP486SX        | pins 1 & 2, 4 & 5, 7 & 8, 10 & 11 |
   |------------------------+-----------------------------------|
   |        80486DX         | pins 1 & 2, 4 & 5, 8 & 9, 11 & 12 |
   |------------------------+-----------------------------------|
   |        80487SX         | pins 1 & 2, 4 & 5, 7 & 8, 10 & 11 |
   |------------------------+-----------------------------------|
   |        80486SX         | pins 2 & 5, 3 & 6, 8 & 11, 9 & 12 |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                     SRAM CONFIGURATION                     |
   |------------------------------------------------------------|
   | Size  |  Cache   | Location |  TAG   |         JP2         |
   |       |   SRAM   |          |        |                     |
   |-------+----------+----------+--------+---------------------|
   | 64KB  | (8) 8K x | Banks 0  | (1) 8K | pins 1 & 2, 4 & 5,  |
   |       |    8     |   & 1    |  x 8   | 7 & 8, and 10 & 11  |
   |-------+----------+----------+--------+---------------------|
   | 128KB | (4) 32K  |  Bank 0  | (1) 8K | pins 1 & 2, 4 & 5,  |
   |       |   x 8    |          |  x 8   | 8 & 9, and 11 & 12  |
   |-------+----------+----------+--------+---------------------|
   | 256KB | (8) 32K  | Banks 0  |  (1)   | pins 2 & 3, 5 & 6,  |
   |       |   x 8    |   & 1    | 32K x  | 8 & 9, and 11 & 12  |
   |       |          |          |   8    |                     |
   +------------------------------------------------------------+