AST RESEARCH, INC.                TECHNICAL BULLETIN #0892            2-16-94


                                      
                                      
                            POWER EXEC CRC ERRORS


PROBLEM:       During serial port communications at speeds greater than 9600
               baud, CRC errors occur every twenty seconds.

CAUSE:         The SL architecture required that the power management design
               implement a "heart-beat" whereby interrupts are disabled for
               about 600us every twenty seconds.  This allows the Power
               Management (PM) to communicate with the Keyboard Controller
               (KBC).  When communications programs operate at higher baud
               rates, they can drop data during this 600us period.  Some
               programs, such as Laplink 5, have incorporated automatic
               retries in case of an error.  Others, such as Procomm for
               Windows, do not, as yet, have this.

SYSTEMS
AFFECTED:      Power Exec

SOLUTION:      There is no resolution at this time.  Future products will not
               have this "heart-beat" problem.