UNIDENTIFIED
============

   486SX/DX/DX2-MAINBOARD

   Processor             80486SX/80486DX/80486DX2                 
   Processor Speed       20/25/33/50(internal)/50/66(internal)MHz 
   Chip Set              UNI                                      
   Video Chip Set        None                                     
   Maximum Onboard       32MB                                     
   Memory                
   Maximum Video Memory  None                                     
   Cache                 64/128/256KB                             
   BIOS                  AMI                                      
   Dimensions            260mm x 220mm                            
   I/O Options           32-bit VESA local bus slots (3)          
   NPU Options           None                                     

<gopher://bitreich.org/I/th99/m/U-Z/33723-1.png>
   

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   | Purpose       | Location | Purpose              | Location |
   |---------------+----------+----------------------+----------|
   | Turbo switch  |    H1    | Reset switch         |    H5    |
   |---------------+----------+----------------------+----------|
   | Turbo LED     |    H2    | External battery     |    J1    |
   |---------------+----------+----------------------+----------|
   | Power LED &   |    H3    | 32-bit VESA local    |  SL1 -   |
   | keylock       |          | bus slots            |   SL3    |
   |---------------+----------+----------------------+----------|
   | Speaker       |    H4    |                      |          |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 USER CONFIGURABLE SETTINGS                 |
   |------------------------------------------------------------|
   |               Function                | Label |  Position  |
   |---------------------------------------+-------+------------|
   |>> | Turbo enabled                     |  H1   |   Closed   |
   |---+-----------------------------------+-------+------------|
   |   | Turbo enabled through keyboard    |  H1   |    Open    |
   |   | (CTRL, ALT, +)                    |       |            |
   |---+-----------------------------------+-------+------------|
   |   | Turbo disabled through keyboard   |  H1   |    Open    |
   |   | (CTRL, ALT, -)                    |       |            |
   |---+-----------------------------------+-------+------------|
   |>> | CMOS memory normal operation      |  J1   | Pins 2 & 3 |
   |   |                                   |       |   closed   |
   |---+-----------------------------------+-------+------------|
   |   | CMOS memory clear                 |  J1   | Pins 3 & 4 |
   |   |                                   |       |   closed   |
   |---+-----------------------------------+-------+------------|
   |   | Battery type select external      |  J1   |   Closed   |
   |---+-----------------------------------+-------+------------|
   |>> | Monitor type select color         |  J3   |   Closed   |
   |---+-----------------------------------+-------+------------|
   |   | Monitor type select monochrome    |  J3   |    Open    |
   |---+-----------------------------------+-------+------------|
   |>> | VL-BUS clock normal operation     | JP43  | Pins 2 & 3 |
   |   |                                   |       |   closed   |
   |---+-----------------------------------+-------+------------|
   |   | VL-BUS clock adjusted             | JP43  | 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) 256K x 9    |     (4) 1M x 9     |
   |------------------+--------------------+--------------------|
   |       8MB        |     (4) 1M x 9     |     (4) 1M x 9     |
   |------------------+--------------------+--------------------|
   |       16MB       |     (4) 4M x 9     |        None        |
   |------------------+--------------------+--------------------|
   |       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     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                    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  |  JP6   |  JP7   |  JP8   |           JP9           |
   |-------+--------+--------+--------+-------------------------|
   | 64KB  |  Open  | Closed |  Open  |    Pins 1 & 2 closed    |
   |-------+--------+--------+--------+-------------------------|
   | 128KB |  Open  | Closed | Closed |    Pins 1 & 2, 3 & 4    |
   |       |        |        |        |         closed          |
   |-------+--------+--------+--------+-------------------------|
   | 256KB | Closed | Closed | Closed |    Pins 1 & 2, 4 & 5    |
   |       |        |        |        |         closed          |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                    CPU SPEED SELECTION                     |
   |------------------------------------------------------------|
   |     Speed     |     JP29     |     JP30     |     JP31     |
   |---------------+--------------+--------------+--------------|
   |     20MHz     |     Open     |    Closed    |     Open     |
   |---------------+--------------+--------------+--------------|
   |     25MHz     |    Closed    |     Open     |    Closed    |
   |---------------+--------------+--------------+--------------|
   |     33MHz     |    Closed    |    Closed    |     Open     |
   |---------------+--------------+--------------+--------------|
   |    50iMHz     |    Closed    |     Open     |    Closed    |
   |---------------+--------------+--------------+--------------|
   |     50MHz     |     Open     |    Closed    |     Open     |
   |---------------+--------------+--------------+--------------|
   |    66iMHz     |    Closed    |    Closed    |     Open     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                     CPU TYPE SELECTION                     |
   |------------------------------------------------------------|
   |           Type           |               JP4               |
   |--------------------------+---------------------------------|
   |         80486SX          |        Pins 5 & 6 closed        |
   |--------------------------+---------------------------------|
   |         80486DX          | Pins 1 & 2, 4 & 5, 6 & 7 closed |
   |--------------------------+---------------------------------|
   |         80486DX2         | Pins 1 & 2, 4 & 5, 6 & 7 closed |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                VL BUS WAIT STATE SELECTION                 |
   |------------------------------------------------------------|
   |             Setting             |           JP20           |
   |---------------------------------+--------------------------|
   |        |           0            |           Open           |
   |--------+------------------------+--------------------------|
   |>>      |           1            |          Closed          |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                   VL BUS SPEED SELECTION                   |
   |------------------------------------------------------------|
   |              Speed              |           JP19           |
   |---------------------------------+--------------------------|
   |    |          <= 33MHz          |           Open           |
   |----+----------------------------+--------------------------|
   |>>  |          >33 MHz           |          Closed          |
   +------------------------------------------------------------+