AST-3G Plus II                                      AST Part Number 202161-001

The AST-3G Plus II is a video graphics adapter for use with the IBM PC/XT, IBM
PC/AT and 100% compatible machines.  The 3G Plus II is an EGA (Enhanced
Graphics Adapter) board.  Through hardware reconfiguration, the 3G Plus II can
also act as a standard color graphics adapter or as a monochrome display
adapter.  The 3G Plus II can also emulate Hercules monochrome graphics.
Standard video memory installed on the 3G Plus II is 256K.

The 3G Plus II 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 Plus II.  These video jacks are not enabled unless the
feature adapter is attached.


SWITCH SETTINGS

    If AST-3G Plus II is the primary video adapter

          SW1 Switch
        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 Plus II is the secondary video adapter

          SW1 Switch
        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

    SW1-5 - Emulation Switch

        By turning on the emulation option (SW1-5), the 3G Plus II will
        emulate CGA graphics on an EGA monitor.  This is useful for cases when
        your software does not support Enhanced Graphics.  If you have a
        monochrome monitor, turning SW1-5 on will allow the 3G Plus II to
        emulate Hercules graphics.  The emulation mode can be used with the 3G
        Plus II in the primary or secondary position.

    SW1-6 - Auto Configuration

        Turning SW1-6 to the "on" position enables the auto configuration
        mode.  This allows the 3G Plus II to detect the type of monitor it is
        attached to and configure itself.  If SW1-6 is enabled, the first four
        switches on bank one are ignored.


JUMPER SETTINGS

    E1 - I/O Address
        Connect pins 1 & 2 for address 3xx.






SWITCH AND JUMPER LOCATIONS

    ͻ
                                SW1   
                                  6+-Ķ
         *E1                       |  
         *                        1+- 
                                      
                                      
                                      
                                      
                                      
                                     Ķ
    ͻ            ͼ 
                    ͼ      
                                        
