J-BOND COMPUTER SYSTEMS CORPORATION
===================================

   486 VL450C-1

   Processor  80486SX/80486DX/80486DX2                              
   Processor  20/25/33/40(internal)/50(internal)/50/66(internal)MHz 
   Speed      
   Chip Set   SIS                                                   
   Max.       32MB                                                  
   Onboard    
   DRAM       
   Cache      64/128/256KB                                          
   BIOS       AMI                                                   
   Dimensions 230mm x 218mm                                         
   I/O        32-bit VESA local bus slots (2)                       
   Options    
   NPU        None                                                  
   Options    

<gopher://bitreich.org/I/th99/m/I-L/32017-1.png>
   

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   | Purpose           | Location | Purpose          | Location |
   |-------------------+----------+------------------+----------|
   | External battery  |    J1    | Turbo LED        |    J5    |
   |-------------------+----------+------------------+----------|
   | Power LED &       |    J2    | Reset switch     |    J6    |
   | keylock           |          |                  |          |
   |-------------------+----------+------------------+----------|
   | Speaker           |    J3    | 32-bit VESA      |  SL1 &   |
   |                   |          | Local bus slots  |   SL2    |
   |-------------------+----------+------------------+----------|
   | Turbo switch      |    J4    |                  |          |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 USER CONFIGURABLE SETTINGS                 |
   |------------------------------------------------------------|
   |              Function               | Jumper  |  Position  |
   |-------------------------------------+---------+------------|
   |>> | Factory configured - do not     |   J7    |    Open    |
   |   | alter                           |         |            |
   |---+---------------------------------+---------+------------|
   |>> | A20 type select fast gate       |   JP2   | pins 1 & 2 |
   |   |                                 |         |   closed   |
   |---+---------------------------------+---------+------------|
   |   | A20 type select keyboard        |   JP2   | pins 2 & 3 |
   |   | controller gate                 |         |   closed   |
   |---+---------------------------------+---------+------------|
   |>> | CMOS memory normal operation    |   JP3   |    Open    |
   |---+---------------------------------+---------+------------|
   |   | CMOS memory clear               |   JP3   | pins 2 & 3 |
   |   |                                 |         |   closed   |
   |---+---------------------------------+---------+------------|
   |>> | VESA local bus normal operation |  JP27   | pins 1 & 2 |
   |   |                                 |         |   closed   |
   |---+---------------------------------+---------+------------|
   |   | VESA local bus compatibility    |  JP27   | pins 2 & 3 |
   |   | problems (See note below)       |         |   closed   |
   |---+---------------------------------+---------+------------|
   |>> | PQFP CPU enabled                |  JSX6   |    Open    |
   |---+---------------------------------+---------+------------|
   |   | PQFP CPU disabled               |  JSX6   |   Closed   |
   |------------------------------------------------------------|
   | Note: If compatibility problems arise with nonstandard     |
   | VESA local bus peripherals, jumper pins 2 & 3.             |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                     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        |
   |------------------+--------------------+--------------------|
   |       8MB        |     (4) 1M x 9     |     (4) 1M x 9     |
   |------------------+--------------------+--------------------|
   |       16MB       |     (4) 4M x 9     |        NONE        |
   |------------------+--------------------+--------------------|
   |       20MB       |     (4) 1M x 9     |     (4) 4M 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 or (1) 32K  |
   |       |             |             |          x 8           |
   |-------+-------------+-------------+------------------------|
   | 128KB | (4) 32K x 8 |    NONE     | (1) 8K x 8 or (1) 32K  |
   |       |             |             |          x 8           |
   |-------+-------------+-------------+------------------------|
   | 256KB | (4) 32K x 8 | (4) 32K x 8 |      (1) 32K x 8       |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 CACHE JUMPER CONFIGURATION                 |
   |------------------------------------------------------------|
   |  Size   |   JP4    |        JP5        |   JP6   |   JP7   |
   |---------+----------+-------------------+---------+---------|
   |  64KB   |   Open   |       Open        |  Open   |  Open   |
   |---------+----------+-------------------+---------+---------|
   |  128KB  |  Closed  | pins 1 & 2 closed |  Open   | Closed  |
   |---------+----------+-------------------+---------+---------|
   |  256KB  |  Closed  | pins 2 & 3 closed | Closed  | Closed  |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                   CPU TYPE CONFIGURATION                   |
   |------------------------------------------------------------|
   |    Type     |  JSX1   |  JSX2   |  JSX3  |  JSX4  |  JSX5  |
   |-------------+---------+---------+--------+--------+--------|
   |   80486SX   |  Open   |  Open   |  Open  | Closed |  Open  |
   |-------------+---------+---------+--------+--------+--------|
   |   80487SX   |  Open   | Closed  | Closed |  Open  | Closed |
   |-------------+---------+---------+--------+--------+--------|
   | 80486DX/DX2 | Closed  |  Open   | Closed |  Open  | Closed |
   |-------------+---------+---------+--------+--------+--------|
   |  Overdrive  |  Open   | Closed  | Closed |  Open  | Closed |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                  CPU SPEED CONFIGURATION                   |
   |------------------------------------------------------------|
   |     Speed     |     JP20     |     JP21     |     JP22     |
   |---------------+--------------+--------------+--------------|
   |     20MHz     |     Open     |     Open     |     Open     |
   |---------------+--------------+--------------+--------------|
   |     25MHz     |    Closed    |     Open     |     Open     |
   |---------------+--------------+--------------+--------------|
   |     33MHz     |    Closed    |    Closed    |    Closed    |
   |---------------+--------------+--------------+--------------|
   |     40MHz     |    Closed    |    Closed    |     Open     |
   |---------------+--------------+--------------+--------------|
   |    50iMHz     |    Closed    |     Open     |     Open     |
   |---------------+--------------+--------------+--------------|
   |     50MHz     |     Open     |     Open     |    Closed    |
   |---------------+--------------+--------------+--------------|
   |    66iMHz     |    Closed    |    Closed    |    Closed    |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |          VESA WAIT STATE/BUS SPEED CONFIGURATION           |
   |------------------------------------------------------------|
   | CPU speed |  Wait states  |  JP8   |  JP9  | JP10  | JP11  |
   |-----------+---------------+--------+-------+-------+-------|
   |  < 33MHz  | 0 wait states |  Open  | Open  | Open  | Open  |
   |-----------+---------------+--------+-------+-------+-------|
   |  > 33MHz  | 1 wait state  | Short  | Short | Short | Short |
   +------------------------------------------------------------+