    AST RESEARCH, INC.         TECHNICAL BULLETIN #0855               08-11-93

                              POWER EXEC AND AT&T MODEM

    PROBLEM:       The AT&T PCMCIA 14.4 Data / 9600 Fax V.32 Modem does not wake
                   up the Power Exec from suspend mode upon a Modem Ring.

    CAUSE:         When the AT&T Paradyne Modem is used, the signal STSCHG/RI
                   (Pin 6 or 61 of the Intel 82365SL PCIC chip) is not being
                   activated by the AT&T Card, in response to the "RING" of an
                   incoming call.  This signal remains inactive during a "RING"
                   whether or not the system is in Suspend Mode.

                   The AT&T Paradyne 3700 PCMCIA Interface specification revision
                   1.4a states: Bit 6 (SigChg) of the CCSR (Card Configuration
                   and Status Register) if set to "1", activates the STSCHG
                   signal (Pin 63 of the card).  If reset to "0", STSCHG is kept
                   inactive.  This bit can be enabled or disabled by the Host PC.

                   With the Power Exec, it was determined that after loading the
                   CCU and SSU utilities, the Card Configuration and Status
                   register (CCSR) has Bit 6 reset to "0".  According to the AT&T
                   specifications, this will disable the STSCHG line.  This
                   prevents any "Rings" from being passed on to the PCIC chip via
                   the STSCHG/RI line.

    SYSTEMS
    AFFECTED:      AST Power Exec Notebook family using AT&T Modems.

    SOLUTION:      There are three criteria that must be met to enable the AT&T
                   modem to wake the Power Exec up from suspend mode:

                   1) Use AST CCU&SSU Utilities version 1.05 or higher.  This
                      file is available on the AST BBS under the file name of
                      PECCU.EXE.

                   2) Use the Microsoft DOS 6.0 utility called POWER.EXE  The
                      following line, DEVICE=C:\DOS\POWER.EXE, must be added to
                      the CONFIG.SYS file to enable this utility.  This is
                      described in further detail on page 256 of AST's "Microsoft
                      Windows and MS-DOS 6 User's Guide", under the heading of
                      "Conserving Power on Your Laptop Computer".  (Customers
                      must upgrade to MS-DOS 6 to obtain this file.)

                   3) Upgrade the AT&T Modem to Firmware version 1.30 or higher
                      which supports the "Idle or Minimum Power Mode".  The
                      current version is 1.45.  This firmware will not ship from
                      AST until September 1993.  Customers experiencing this
                      problem can dial the AT&T BBS (813 532-5254) and download a
                      copy (KIT145.EXE) of the firmware.