AST-3G                                              AST Part Number 202091-001

The AST-3G is a video graphics adapter for use with the IBM PC/XT, IBM PC/AT
and 100% compatible machines.  The 3G is an EGA (Enhanced Graphics Adapter)
board.  Through hardware reconfiguration, the 3G can also act as a standard
color graphics adapter or as a monochrome display adapter.  The 3G does not
support Hercules monochrome graphics.  Standard video memory installed on the
3G is 64K, upgradable to 256K.  There is an optional parallel port available
for this board.

The 3G Adapter is compatible with the IBM EGA feature connector.  The feature
adapter allows for video input/output through the RCA video jacks at the rear
of the 3G.  These video jacks are not enabled unless the feature adapter is
attached.


SWITCH SETTINGS

    If AST-3G is the primary video adapter...

        Switch SW1

            Block Settings      3G Mode       2'nd Adapter     Monitor
             1   2   3   4     at Powerup         Mode          Type
            --- --- --- ---   ------------   --------------  ------------
            OFF  ON  ON OFF     EGA 80x25       MDA 80x25     EGA
             ON  ON  ON OFF     CGA 80x25       MDA 80x25     EGA or CGA
             ON OFF OFF  ON     CGA 40x25       MDA 80x25     EGA or CGA
            OFF OFF  ON OFF     MDA 80x25       CGA 80x25     MONOCHROME
             ON OFF  ON OFF     MDA 80x25       CGA 40x25     MONOCHROME

    If AST-3G is the secondary video adapter...

        Switch SW1

            Block Settings                       Primary       Monitor
             1   2   3   4       3G Mode      Adapter Mode   Type (on 3G)
            --- --- --- ---   ------------   --------------  ------------
            OFF OFF  ON  ON     EGA 80x25       MDA 80x25     EGA
             ON OFF  ON  ON     CGA 80x25       MDA 80x25     EGA or CGA
             ON  ON  ON  ON     CGA 40x25       MDA 80x25     EGA or CGA
            OFF  ON OFF  ON     MDA 80x25       CGA 80x25     MONOCHROME
             ON  ON OFF  ON     MDA 80x25       CGA 40x25     MONOCHROME


JUMPER SETTINGS

    E1/E2 Location - Base I/O Address
        Leave E2 position connected for 3xx

    E5 Location - Video Memory
        Connect for 256K; Open for 64K

    E7/E8 Location - Parallel IRQ
        Connect E7 for IRQ7 (LPT1:); Connect E8 for IRQ5 (LPT2:)

    E9/E10 Location - Monitor Type
        Connect E9 for CGA or Mono; Connect E10 for EGA

    LPT1 Location
        Connect to enable parallel option as LPT1: (378h)

    LPT2 Location
        Connect to enable parallel option as LPT2: (278h)







SWITCH AND JUMPER LOCATIONS

    ͻ
         **                                                         
        E1/E2                                                    +-Ķ
                                                             SW1 |  
                                                                 +- 
                     LPT1 *                    *              *     
                                              E5              *     
                         * LPT2                             E9/E10  
                                                                    
                                                   **               
                                                  E7/E8            Ķ
    ͻ            ͼ 
                                                  ͼ      
                                                                      
