AMERICAN MEGATRENDS, INC.
=========================

   ENTERPRISE-IV EISA VLB

   Processor    80486SX/80487SX/80486DX/ODP486SX/80486DX2/Pentium 
                Overdrive                                         
   Processor    25/33/50(internal)/50/66(internal)MHz             
   Speed        
   Chip Set     AMI                                               
   Max. Onboard 256MB                                             
   DRAM         
   Cache        256KB                                             
   BIOS         AMI                                               
   Dimensions   330mm x 218mm                                     
   I/O Options  32-bit VESA local bus slots (2), floppy drive     
                interface,                                        
                                                                  
                IDE interface, parallel port, serial ports (2)    
   NPU Options  None                                              

<gopher://bitreich.org/I/th99/m/A-B/31701-1.png>
   

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   | Purpose            | Location | Purpose         | Location |
   |--------------------+----------+-----------------+----------|
   | Serial port 1      |    J2    | Power LED &     |   J34    |
   |                    |          | keylock         |          |
   |--------------------+----------+-----------------+----------|
   | Serial port 2      |    J3    | Turbo switch    |   J39    |
   |--------------------+----------+-----------------+----------|
   | Parallel port      |    J4    | Speaker         |   J40    |
   |--------------------+----------+-----------------+----------|
   | IDE interface LED  |    J5    | Reset switch    |   J41    |
   |--------------------+----------+-----------------+----------|
   | Floppy drive       |    J6    | Turbo LED       |   J42    |
   | interface          |          |                 |          |
   |--------------------+----------+-----------------+----------|
   | IDE interface      |    J9    | 32-bit VESA     |    S1    |
   |                    |          | Local bus slot  |          |
   |--------------------+----------+-----------------+----------|
   | PS/2 mouse         |   J11    | 32-bit VESA     |    S2    |
   |                    |          | Local bus slot  |          |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 USER CONFIGURABLE SETTINGS                 |
   |------------------------------------------------------------|
   |           Function            | Jumper/Switch |  Position  |
   |-------------------------------+---------------+------------|
   |>> | Factory configured - do   |      J10      |    N/A     |
   |   | not alter                 |               |            |
   |---+---------------------------+---------------+------------|
   |>> | Factory configured - do   |      J21      |    N/A     |
   |   | not alter                 |               |            |
   |---+---------------------------+---------------+------------|
   |>> | CPU low priority          |      J31      | pins 1 & 2 |
   |   |                           |               |   closed   |
   |---+---------------------------+---------------+------------|
   |   | CPU high priority         |      J31      | pins 2 & 3 |
   |   |                           |               |   closed   |
   |---+---------------------------+---------------+------------|
   |>> | Factory configured - do   |      J38      |    N/A     |
   |   | not alter                 |               |            |
   |---+---------------------------+---------------+------------|
   |>> | Factory configured - do   | SW1/switch 1  |    Off     |
   |   | not alter                 |               |            |
   |---+---------------------------+---------------+------------|
   |>> | Monitor type select       | SW1/switch 2  |    Off     |
   |   | monochrome                |               |            |
   |---+---------------------------+---------------+------------|
   |   | Monitor type select color | SW1/switch 2  |     On     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                     DRAM CONFIGURATION                     |
   |------------------------------------------------------------|
   | Size  |    Bank 0     |   Bank 1   |  Bank 2   |  Bank 3   |
   |-------+---------------+------------+-----------+-----------|
   |  1MB  | (1) 256K x 36 |    None    |   None    |   None    |
   |-------+---------------+------------+-----------+-----------|
   |  2MB  | (1) 256K x 36 | (1) 256K x |   None    |   None    |
   |       |               |     36     |           |           |
   |-------+---------------+------------+-----------+-----------|
   |  4MB  |  (1) 1M x 36  |    None    |   None    |   None    |
   |-------+---------------+------------+-----------+-----------|
   |  6MB  | (1) 256K x 36 | (1) 256K x | (1) 1M x  |   None    |
   |       |               |     36     |    36     |           |
   |-------+---------------+------------+-----------+-----------|
   |  8MB  |  (1) 1M x 36  |  (1) 1M x  |   None    |   None    |
   |       |               |     36     |           |           |
   |-------+---------------+------------+-----------+-----------|
   | 10MB  | (1) 256K x 36 | (1) 256K x | (1) 1M x  | (1) 1M x  |
   |       |               |     36     |    36     |    36     |
   |-------+---------------+------------+-----------+-----------|
   | 12MB  |  (1) 1M x 36  |  (1) 1M x  | (1) 1M x  |   None    |
   |       |               |     36     |    36     |           |
   |-------+---------------+------------+-----------+-----------|
   | 16MB  |  (1) 1M x 36  |  (1) 1M x  | (1) 1M x  | (1) 1M x  |
   |       |               |     36     |    36     |    36     |
   |-------+---------------+------------+-----------+-----------|
   | 16MB  |  (1) 4M x 36  |    None    |   None    |   None    |
   |-------+---------------+------------+-----------+-----------|
   | 18MB  | (1) 256K x 36 | (1) 256K x | (1) 4M x  |   None    |
   |       |               |     36     |    36     |           |
   |-------+---------------+------------+-----------+-----------|
   | 20MB  |  (1) 1M x 36  |  (1) 4M x  |   None    |   None    |
   |       |               |     36     |           |           |
   |-------+---------------+------------+-----------+-----------|
   | 24MB  |  (1) 1M x 36  |  (1) 1M x  | (1) 4M x  |   None    |
   |       |               |     36     |    36     |           |
   |-------+---------------+------------+-----------+-----------|
   | 32MB  |  (1) 4M x 36  |  (1) 4M x  |   None    |   None    |
   |       |               |     36     |           |           |
   |-------+---------------+------------+-----------+-----------|
   | 36MB  |  (1) 1M x 36  |  (1) 4M x  | (1) 4M x  |   None    |
   |       |               |     36     |    36     |           |
   |-------+---------------+------------+-----------+-----------|
   | 40MB  |  (1) 1M x 36  |  (1) 1M x  | (1) 4M x  | (1) 4M x  |
   |       |               |     36     |    36     |    36     |
   |-------+---------------+------------+-----------+-----------|
   | 48MB  |  (1) 4M x 36  |  (1) 4M x  | (1) 4M x  |   None    |
   |       |               |     36     |    36     |           |
   |-------+---------------+------------+-----------+-----------|
   | 64MB  |  (1) 4M x 36  |  (1) 4M x  | (1) 4M x  | (1) 4M x  |
   |       |               |     36     |    36     |    36     |
   |-------+---------------+------------+-----------+-----------|
   | 64MB  | (1) 16M x 36  |    None    |   None    |   None    |
   |-------+---------------+------------+-----------+-----------|
   | 128MB | (1) 16M x 36  | (1) 16M x  |   None    |   None    |
   |       |               |     36     |           |           |
   |-------+---------------+------------+-----------+-----------|
   | 192MB | (1) 16M x 36  | (1) 16M x  | (1) 16M x |   None    |
   |       |               |     36     |    36     |           |
   |-------+---------------+------------+-----------+-----------|
   | 256MB | (1) 16M x 36  | (1) 16M x  | (1) 16M x | (1) 16M x |
   |       |               |     36     |    36     |    36     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                  CPU SPEED CONFIGURATION                   |
   |------------------------------------------------------------|
   |     Speed     |     J12      |     J13      |     J14      |
   |---------------+--------------+--------------+--------------|
   |     25MHz     |     Open     |     Open     |     Open     |
   |---------------+--------------+--------------+--------------|
   |     33MHz     |     Open     |    Closed    |     Open     |
   |---------------+--------------+--------------+--------------|
   |    50i MHz    |     Open     |     Open     |     Open     |
   |---------------+--------------+--------------+--------------|
   |     50MHz     |    Closed    |     Open     |    Closed    |
   |---------------+--------------+--------------+--------------|
   |    66i MHz    |     Open     |    Closed    |     Open     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                   CPU TYPE CONFIGURATION                   |
   |------------------------------------------------------------|
   |    PGA CPU    |    PQFP CPU     |  J15   |  J16   |  J43   |
   |---------------+-----------------+--------+--------+--------|
   |     None      | 80486SX,80486DX |  N/A   |  N/A   |  Open  |
   |---------------+-----------------+--------+--------+--------|
   |   ODP486SX,   | 80486SX,80486DX |  1&2,  | pins 2 | Closed |
   |   80487SX,    |                 |  3&4   |  & 3   |        |
   |   ODP586SX    |                 |        |        |        |
   |---------------+-----------------+--------+--------+--------|
   |   ODP486SX,   |      None       |  1&2,  | pins 2 |  N/A   |
   |   80487SX,    |                 |  3&4   |  & 3   |        |
   |   ODP586SX    |                 |        |        |        |
   |---------------+-----------------+--------+--------+--------|
   |   80486DX,    |      None       |  1&2,  | pins 1 |  N/A   |
   |   80486DX2    |                 |  3&4   |  & 2   |        |
   |---------------+-----------------+--------+--------+--------|
   |   80486DX,    | 80486SX,80486DX |  1&2,  | pins 1 | Closed |
   |   80486DX2    |                 |  3&4   |  & 2   |        |
   |---------------+-----------------+--------+--------+--------|
   |    80486SX    |      None       | pins 2 |  N/A   |  N/A   |
   |               |                 |  & 3   |        |        |
   |---------------+-----------------+--------+--------+--------|
   |    80486SX    | 80486SX,80486DX | pins 2 |  N/A   | Closed |
   |               |                 |  & 3   |        |        |
   |------------------------------------------------------------|
   | Note:Pins designated should be in the closed position.     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |              SERIAL PORT INTERRUPT SELECTION               |
   |------------------------------------------------------------|
   |   Port 1   | Port 2 (J3) |      J22       |      J23       |
   |    (J2)    |             |                |                |
   |------------+-------------+----------------+----------------|
   |>>  | IRQ4  |    IRQ3     |   pins 2 & 3   |   pins 1 & 2   |
   |    |       |             |     closed     |     closed     |
   |----+-------+-------------+----------------+----------------|
   |    | IRQ3  |    IRQ4     |   pins 1 & 2   |   pins 2 & 3   |
   |    |       |             |     closed     |     closed     |
   +------------------------------------------------------------+