    AST RESEARCH, INC.         TECHNICAL BULLETIN #0885               01-17-94

                  MEMORY ERRORS WHILE USING TEXAS INSTRUMENT SIMMS

    PROBLEM:       When running the AST Advanced Diagnostics program,
                   intermittent memory failures occur while executing the
                   "Walking Zeroes and Ones" test of the memory diagnostics
                   module.

                   Also, while running under IBM OS/2 2.1, loading an application
                   in a "WIN OS/2" window causes a "General Protection Fault",
                   which hangs the system.

    CAUSE:         Defective SIMM modules from Texas Instruments. The problem has
                   been identified as a design defect within the Revision C die
                   of TI's TMS44400 DRAM chip.  The SIMM has a TI part number
                   TM124MBK36R-7.  The AST part number is 104000-191

    AFFECTED
    SYSTEMS:       Any system with Texas Instrument SIMMS identified as Revision
                   C installed. The revision number can be identified by
                   observing the part number on any of the memory IC's on the
                   SIMM module.  The third line of the part number consists of
                   three letters, e.g. "TCP". The middle letter of the sequence
                   is the revision of the individual IC.  In this example the
                   revision is C, which indicates a defective SIMM.

    SOLUTION:      Replace the defective revisions of the SIMMS with a known good
                   revision - either revision B or a revision above C.