    AST RESEARCH, INC.           TECHNICAL BULLETIN # 1314           9-25-95

                       MANHATTAN X5090 AND CONNER CFP2105S DRIVES

    PROBLEM:    When attempting to duplex Conner CFP2105S drives under NetWare,
                the user may observe one or more of the following error messages
                when trying to mirror or remirror the drives:
                    * (SDMSNET4) CAM Error: CMD_TIMEOUT (8D010000)
                    * Device #2 Conner :CFP2105S 2.14GB:2B4B (8D010000)
                      deactivated by driver due to device failure
                    * Volume SYS still operational despite drive deactivation
                    * Aborted remirror of partition #1
                    * The mirrored partitions on this system are not all
                      synchronized

    SOLUTION:   Disable "Tag Command Queuing" on the NCR controller by adding
                the "qtags=disable" startup switch to the NCRSDMSx load line.
                In the case of NetWare 4.X, the user would enter the following
                command, while retaining any other switches the user might
                already be using, in the STARTUP.NCF file:

                      LOAD NCRSDMS4 qtags=disable

                Informal benchmarking has revealed there is no performance
                difference between running with "Tag Command Queuing" either
                enabled or disabled.

    SYSTEMS
    AFFECTED:   Part Number   Description
                501503-XXX    AST Manhattan P5090