J-MARK COMPUTER CORPORATION
===========================

   JET-486

   Processor             80486SX/80487SX/80486DX/80486DX2         
   Processor Speed       20/25/33/50(internal)/50/66(internal)MHz 
   Chip Set              OPTI                                     
   Max. Onboard DRAM     32MB                                     
   Cache                 64/128/256KB                             
   BIOS                  AMI/Award                                
   Dimensions            220mm x 220mm                            
   I/O Options           None                                     
   NPU Options           None                                     

<gopher://bitreich.org/I/th99/m/I-L/31081-1.png>
   

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   | Purpose             | Location | Purpose        | Location |
   |---------------------+----------+----------------+----------|
   | External battery    |    J1    | Turbo LED      |   JP11   |
   |---------------------+----------+----------------+----------|
   | Speaker             |   J17    | Reset switch   |   SW1    |
   |---------------------+----------+----------------+----------|
   | Power LED & keylock |   J18    | Turbo switch   |   SW2    |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 USER CONFIGURABLE SETTINGS                 |
   |------------------------------------------------------------|
   |              Function              | Jumper |   Position   |
   |------------------------------------+--------+--------------|
   |>> | CMOS memory normal operation   |  JP1   |  pins 2 & 3  |
   |   |                                |        |    closed    |
   |---+--------------------------------+--------+--------------|
   |   | CMOS memory clear              |  JP1   |  pins 1 & 2  |
   |   |                                |        |    closed    |
   |---+--------------------------------+--------+--------------|
   |>> | Monitor type select color      |  JP2   |    Closed    |
   |---+--------------------------------+--------+--------------|
   |   | Monitor type select monochrome |  JP2   |     Open     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                     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     |    Bank 1     |      TAG      |
   |------------+---------------+---------------+---------------|
   |    64KB    |  (4) 8K x 8   |  (4) 8K x 8   |  (1) 8K x 8   |
   |------------+---------------+---------------+---------------|
   |   128KB    |  (4) 32K x 8  |     NONE      |  (1) 8K x 8   |
   |------------+---------------+---------------+---------------|
   |   256KB    |  (4) 32K x 8  |  (4) 32K x 8  |  (1) 32K x 8  |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 CACHE JUMPER CONFIGURATION                 |
   |------------------------------------------------------------|
   |  Size   |        JP3        |   JP4    |   JP6   |   JP7   |
   |---------+-------------------+----------+---------+---------|
   |  64KB   | pins 2 & 3 closed |   Open   |  Open   |  Open   |
   |---------+-------------------+----------+---------+---------|
   |  128KB  | pins 1 & 2 closed |  Closed  | Closed  |  Open   |
   |---------+-------------------+----------+---------+---------|
   |  256KB  | pins 2 & 3 closed |  Closed  | Closed  | Closed  |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                   CPU TYPE CONFIGURATION                   |
   |------------------------------------------------------------|
   |   Type    |        JP8        |  JP9   |       JP10        |
   |-----------+-------------------+--------+-------------------|
   |  80486SX  | pins 2 & 3 closed |  Open  |       Open        |
   |-----------+-------------------+--------+-------------------|
   |  80487SX  | pins 1 & 2 closed | Closed | pins 1 & 2 closed |
   |-----------+-------------------+--------+-------------------|
   |  80486DX  | pins 1 & 2 closed | Closed | pins 2 & 3 closed |
   |-----------+-------------------+--------+-------------------|
   | 80486DX2  | pins 1 & 2 closed | Closed | pins 2 & 3 closed |
   +------------------------------------------------------------+