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    AST RESEARCH, INC.              TECHNICAL BULLETIN # 0990             9-29-94

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                         PREMIUM EXEC PRODUCT VARIATIONS INFORMATION

                       Exec 386SX/20                   Exec 386SX/25       Exec
                                                                          SX/25C
    HARDWARE
    Top Level
    P/N         500795     500843      500843       500850    500867      500884
    Enclosure   Original   Seamless    Seamless     Original  Seamless    Seamless

    (1)Video
    Type        Rev B      Rev B       Rev C        Rev C      Rev C      Color
    Motherboard
    P/N         202390-001 n/a         202390-004  202390-003  202390-003 202478-002

                202390-002 202390-002                          202390-004

    (2)Processor
    Board       Actel      MIKI        MIKI        MIKI       MIKI       MIKI
    Processor
    Board P/N   202392-002 202410-002  202410-002  202410-003 202410-003 202410-010
    System BIOS 1.06-1.09  1.12-1.17   1.12-1.17   1.12-1.17  1.12-1.17  2.00-2.02
    Keyboard
    BIOS        1.03&1.04  Inc. in     Inc. in     Inc. in    Inc. in    Inc. in
                           ASIC Chip   ASIC Chip   ASIC Chip  ASIC Chip  ASIC Chip
    BMC BIOS    1.04-1.06  1.04-1.06   1.04-1.06   1.04-1.06  1.04-1.06  1.06

    1MB SIMM
    (80ns)      Yes        Yes         Yes         n/a        n/a        n/a
    1MB SIMM
    (70ns)      n/a        n/a         n/a         Yes        Yes        Yes
    4MB SIMM
    (80ns)      Yes        Yes         Yes         n/a        n/a        n/a
    4MB SIMM
    (70ns)      n/a        n/a         n/a         Yes        Yes        Yes
    Laplink
    Serial
    Cable       Yes        (3)Yes/No   No          No         No         Yes

    DOS Version 3.3        3.3 & 5.0   5.0         5.0        5.0        5.0

    SOFTWARE
    System
    Utilities
    P/N         910401-031 910401-033  910401-034  910458-031 910458-031 910458-032
    Traveling
    S/W
    Utilities   Yes (3)    Yes/No      No          No         No         No

    User's
    Manual      Yes        Yes         Yes         Yes        Yes        Yes
    DOC-
    UMENT-
    ATION
    Pocket
    Reference   Yes        Yes         Yes         Yes        Yes        Yes
    DOS Manual  Yes        (3)Yes/No   No          No         No         No
    Laplink
    Manual      Yes        (3)Yes/No   No          No         No         No
    Battery
    Watch ManualYes        (3)Yes/No   No          No         No         No

    Notes:
    (1) Rev C Video identifies the enhanced video chipset and, unlike Rev B
        Video, supports "hardware        expand".
    (2) Actel identifies the original board and has two removable chips; Keyboard
        and System BIOS, and is no longer shipped with new systems.  MIKI
        identifies the ASIC version of this board and has only one removable chip,
        the System BIOS.
    (3) Yes/No indicates that this item was originally shipped and then later
        removed.  Yes indicates this item is currently being shipped.

    SYSTEMS
    AFFECTED:         AST
                  PART NUMBER          DESCRIPTION

                  500795-XXX      PREMIUM EXEC 386SX/20
                  500843-XXX      PREMIUM EXEC 386SX/20
                  500850-XXX      PREMIUM EXEC 386SX/25
                  500867-XXX`     PREMIUM EXEC 386SX/25
                  500884-XXX      PREMIUM EXEC 386SX/25 COLOR