DELL COMPUTER CORPORATION
=========================

   SYSTEMS 4XX/L(V), 4XX/MX(V) OPTIPLEX

   Processor    80486SX/80486DX/80486DX2                          
   Processor    25/33/50(internal)/66(internal)MHz                
   Speed        
   Chip Set     Headland                                          
   Max. Onboard 64MB                                              
   DRAM         
   Cache        128KB (on external cache card)                    
   BIOS         Unidentified                                      
   Dimensions   330mm x 218mm                                     
   I/O Options  32-bit external cache card, 32-bit VESA local bus 
                slot, floppy drive interface, IDE interface,      
                parallel port, PS/2 mouse port, serial ports (2), 
                VGA feature connector, VGA port                   
   NPU Options  None                                              

<gopher://bitreich.org/I/th99/m/C-D/32012-1.png>
   

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   | Purpose          | Location | Purpose           | Location |
   |------------------+----------+-------------------+----------|
   | PS/2 mouse port  |   CN1    | Floppy drive      |   CN8    |
   |                  |          | interface         |          |
   |------------------+----------+-------------------+----------|
   | Serial port 1    |   CN2    | IDE interface     |   CN9    |
   |------------------+----------+-------------------+----------|
   | Serial port 2    |   CN3    | External battery  |    J3    |
   |------------------+----------+-------------------+----------|
   | Parallel port    |   CN4    | Control panel     |    J4    |
   |                  |          | connector         |          |
   |------------------+----------+-------------------+----------|
   | VGA port         |   CN5    | IDE interface LED |    J5    |
   |------------------+----------+-------------------+----------|
   | Video memory     |   CN6    | Riser Card        |   SL1    |
   | upgrade module   |          |                   |          |
   |------------------+----------+-------------------+----------|
   | VGA feature      |   CN7    | 32-bit VESA Local |   SL2    |
   | connector        |          | bus/cache slot    |          |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 USER CONFIGURABLE SETTINGS                 |
   |------------------------------------------------------------|
   |              Function               | Jumper  |  Position  |
   |-------------------------------------+---------+------------|
   |>> | VESA riser card disabled        | J1 & J2 |   Closed   |
   |---+---------------------------------+---------+------------|
   |   | VESA riser card enabled         | J1 & J2 |    Open    |
   |---+---------------------------------+---------+------------|
   |>> | IDE IRQ enabled                 |   J6    | pins 2 & 3 |
   |   |                                 |         |   closed   |
   |---+---------------------------------+---------+------------|
   |   | IDE IRQ disabled                |   J6    | pins 1 & 2 |
   |   |                                 |         |   closed   |
   |---+---------------------------------+---------+------------|
   |>> | Factory configured - do not     |   J7    |    Open    |
   |   | alter                           |         |            |
   |---+---------------------------------+---------+------------|
   |>> | PS/2 mouse (IRQ12) enabled      |   J8    |   Closed   |
   |---+---------------------------------+---------+------------|
   |   | PS/2 mouse (IRQ12) disabled     |   J8    |    Open    |
   |---+---------------------------------+---------+------------|
   |>> | Factory configured - do not     |   J9    |    Open    |
   |   | alter                           |         |            |
   |---+---------------------------------+---------+------------|
   |>> | Factory configured - do not     |   J10   |    Open    |
   |   | alter                           |         |            |
   |---+---------------------------------+---------+------------|
   |>> | Flash BIOS write protect        |   J11   |   Closed   |
   |   | disabled                        |         |            |
   |---+---------------------------------+---------+------------|
   |   | Flash BIOS write protect        |   J11   |    Open    |
   |   | enabled                         |         |            |
   |---+---------------------------------+---------+------------|
   |>> | CPU type select PGA             |   J12   |   Closed   |
   |---+---------------------------------+---------+------------|
   |   | CPU type select PQFP            |   J12   |    Open    |
   |---+---------------------------------+---------+------------|
   |>> | CMOS memory normal operation    |   J13   |   Closed   |
   |---+---------------------------------+---------+------------|
   |   | CMOS memory clear               |   J13   |    Open    |
   |---+---------------------------------+---------+------------|
   |>> | I/O controller address select   |   J14   |   Closed   |
   |   | 26Eh-26Fh                       |         |            |
   |---+---------------------------------+---------+------------|
   |   | I/O controller address select   |   J14   |    Open    |
   |   | 398h-399h                       |         |            |
   |---+---------------------------------+---------+------------|
   |>> | Factory configured - do not     |   J15   |    Open    |
   |   | alter                           |         |            |
   |---+---------------------------------+---------+------------|
   |>> | On board VGA enabled            |   J16   |   Closed   |
   |---+---------------------------------+---------+------------|
   |   | On board VGA disabled           |   J16   |    Open    |
   |---+---------------------------------+---------+------------|
   |>> | Factory configured - do not     |   J17   |    Open    |
   |   | alter                           |         |            |
   |---+---------------------------------+---------+------------|
   |>> | Factory configured - do not     |   J18   |    Open    |
   |   | alter                           |         |            |
   |---+---------------------------------+---------+------------|
   |>> | Factory configured - do not     |   J20   |    Open    |
   |   | alter                           |         |            |
   |---+---------------------------------+---------+------------|
   |>> | Factory configured - do not     |   J22   |    Open    |
   |   | alter                           |         |            |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                     DRAM CONFIGURATION                     |
   |------------------------------------------------------------|
   | Size |   Bank 0    |   Bank 1    |   Bank 2   |   Bank 3   |
   |------+-------------+-------------+------------+------------|
   | 4MB  | (1) 1M x 36 |    NONE     |    NONE    |    NONE    |
   |------+-------------+-------------+------------+------------|
   | 8MB  | (1) 1M x 36 | (1) 1M x 36 |    NONE    |    NONE    |
   |------+-------------+-------------+------------+------------|
   | 12MB | (1) 1M x 36 | (1) 1M x 36 |  (1) 1M x  |    NONE    |
   |      |             |             |     36     |            |
   |------+-------------+-------------+------------+------------|
   | 16MB | (1) 1M x 36 | (1) 1M x 36 |  (1) 1M x  |  (1) 1M x  |
   |      |             |             |     36     |     36     |
   |------+-------------+-------------+------------+------------|
   | 16MB | (1) 4M x 36 |    NONE     |    NONE    |    NONE    |
   |------+-------------+-------------+------------+------------|
   | 20MB | (1) 4M x 36 | (1) 1M x 36 |    NONE    |    NONE    |
   |------+-------------+-------------+------------+------------|
   | 24MB | (1) 4M x 36 | (1) 1M x 36 |  (1) 1M x  |    NONE    |
   |      |             |             |     36     |            |
   |------+-------------+-------------+------------+------------|
   | 28MB | (1) 4M x 36 | (1) 1M x 36 |  (1) 1M x  |  (1) 1M x  |
   |      |             |             |     36     |     36     |
   |------+-------------+-------------+------------+------------|
   | 32MB | (1) 4M x 36 | (1) 4M x 36 |    NONE    |    NONE    |
   |------+-------------+-------------+------------+------------|
   | 36MB | (1) 4M x 36 | (1) 4M x 36 |  (1) 1M x  |    NONE    |
   |      |             |             |     36     |            |
   |------+-------------+-------------+------------+------------|
   | 40MB | (1) 4M x 36 | (1) 4M x 36 |  (1) 1M x  |  (1) 1M x  |
   |      |             |             |     36     |     36     |
   |------+-------------+-------------+------------+------------|
   | 48MB | (1) 4M x 36 | (1) 4M x 36 |  (1) 4M x  |    NONE    |
   |      |             |             |     36     |            |
   |------+-------------+-------------+------------+------------|
   | 52MB | (1) 4M x 36 | (1) 4M x 36 |  (1) 4M x  |  (1) 1M x  |
   |      |             |             |     36     |     36     |
   |------+-------------+-------------+------------+------------|
   | 64MB | (1) 4M x 36 | (1) 4M x 36 |  (1) 4M x  |  (1) 4M x  |
   |      |             |             |     36     |     36     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                VESA CPU SPEED CONFIGURATION                |
   |------------------------------------------------------------|
   |       Speed        |        J19        |        J21        |
   |--------------------+-------------------+-------------------|
   |       25MHz        |       Open        |      Closed       |
   |--------------------+-------------------+-------------------|
   |       33MHz        |      Closed       |       Open        |
   |--------------------+-------------------+-------------------|
   |       50iMHz       |       Open        |      Closed       |
   |--------------------+-------------------+-------------------|
   |       66iMHz       |      Closed       |       Open        |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 VIDEO MEMORY CONFIGURATION                 |
   |------------------------------------------------------------|
   |  Size   |    Bank 0     |   Bank 1    |        CN6         |
   |---------+---------------+-------------+--------------------|
   |  512KB  | (4) 128K x 8  |    NONE     |        NONE        |
   |---------+---------------+-------------+--------------------|
   |   1MB   | (4) 128K x 8  | (4) 128K x  |        NONE        |
   |         |               |      8      |                    |
   |---------+---------------+-------------+--------------------|
   |   2MB   | (4) 128K x 8  | (4) 128K x  |   Memory module    |
   |         |               |      8      |                    |
   |------------------------------------------------------------|
   |      Note: Bank 0 is factory installed and is not          |
   |      configurable. To enable 2MB video memory, install     |
   |      memory module over Bank 1 in CN6 connectors.          |
   +------------------------------------------------------------+