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    AST RESEARCH, INC.          TECHNICAL BULLETIN # 0987               9-26-94

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             BRAVO LC 4/100T AND ADVANCED OPERATING SYSTEM INSTALLATION ON
                                     QUANTUM DRIVES

    PROBLEM:        The Bravo LC 4/100T system hangs during advanced operating
                    system installation, including SCO UNIX 3.2.4.2, if drive type
                    AUTO is selected on Quantum LPS AT540MB drives in the CMOS
                    SETUP.  The system hangs when Advanced Operating Systems try
                    to initialize the drive partition.

    CAUSE:          When AST's system BIOS attempts to AUTOSENSE drives that are
                    larger than 1024 cylinders, a problem occurs.  The advanced
                    operating system can not access the drive because the physical
                    hard disk controller does not offer a drive configuration of
                    less than 1024 cylinders.

    SYSTEMS
    AFFECTED:           AST
                    PART NUMBER       DESCRIPTION

                    501381-007      BRAVO LC 4-100T

    SOLUTION:       On Quantum LPS 540AT drives (firmware TB54A01A revision 04-c),
                    select USER DEFINED drive type with 16=heads, 59=sectors, and
                    1024=cylinders. With these settings the system does not hang
                    and SCO UNIX proceeds with the installation normally.

                    NOTE: This information also applies to other operating system
                    and software such as Novell version 3.12, Windows NT version
                    3.1, and OS/2 version 2.1.