Premium/286 System Board                            AST Part Number 202143-003
                                                                    202143-004

This is the motherboard for the AST Premium/286 Computer.  The Premium/286
operates at 10MHz with zero wait state memory and two wait states on the BUS.
There are seven BUS slots on this board: One 8-bit and six 16-bit, with two of
the 16-bit slots having fASTslot extensions.  One of the fASTslots is reserved
for system memory (on the fASTram board).  The additional fASTslot can be used
for more zero wait state memory or for the FastBoard/386 upgrade option (AST
Part Number 500494-001).

The Premium/286 System Board has several standard features, including:

    - RS-232 Serial port configurable as COM1: or COM2:
    - Parallel port configurable as LPT1:, LPT2:, or LPT3: *
    - Support for Intel 80287 Coprocessor (8MHz)
    - Integrated floppy controller

    * LPT3: is supported at Hex Address 278h only if LPT1: is present
      at 3BCh and LPT2: is at 378h.  If 3BCh is not present, DOS will
      recognize 378h as LPT1: and 278h as LPT2:.


JUMPER SETTINGS

    E22 thru E29 - I/O PORT ADDRESSING

                              JUMPERS
        PORT   IRQ   HEX     INSTALLED
        ----   ---   ---     ---------
        COM1    4    3F8     E23 & E28 (DEFAULT)
        COM2    3    2F8     E22 & E29

        LPT1    7    378     E24 & E26 (DEFAULT)
        LPT2    5    278     E25 & E27
        LPT1    7    3BC     E24 & E25 (OPTIONAL LPT1: SETTING)

        NOTE: To disable motherboard serial communications, remove jumpers at
              positions E22, E23, E28, and E29.  To disable motherboard
              parallel communications, remove positions E24, E25, E26, and E27.

    E33 - ON-BOARD FLOPPY CONTROLLER
        INSTALLED - Disabled
        REMOVED   - Enabled  (Default)

    E1/E15/E16 - 80287 SPEED
        8MHz - E15 INSTALLED; E1 & E16 REMOVED
        5MHz - E1 & E16 INSTALLED; E15 REMOVED

    FACTORY TEST
        The following jumper positions should remain installed:

        E5,   E6,   E11,  E14,  E17,  E20, E21,
        E30*, E31*, E34*, E36*, E38*, E40*

    The following jumper positions should remain open (removed).

        E2,  E3,  E4,  E7,   E8,   E9,   E10, E12,
        E13, E18, E19, E32*, E35*, E37*, E39*

        * - May not be present on later revision boards






CONNECTORS

    J19 - Floppy Connector - A: & B:
    J20 - Third Floppy Connector
    J21 - Power Supply
    J22 - Battery
    J23 - Control Panel (LEDs, Keyboard Lock, Reset Button)
    J24 - Speaker


JUMPER AND CONNECTOR LOCATIONS

    ͻ
                                               
      E1 *   E2-E14                  
             *****                   
             ******                  
             E19-21    
               ***     
                                     
     ** E15-16                                          *          
               ** <-------E17-18                        *<---E22-  
     J23 ****    ***                                    *    E29   
                 J24                  * *               *          
                                     J* *J           *             
                                     1* *2  * E33   J*             
                                     9* *0          2*             
                                      * *           1*  *          
                                                     *  *<---J22   
                                                                   
    ͼ
