    AST RESEARCH, INC.         TECHNICAL BULLETIN #0790                  12-01-92

                      BRAVO 4/33 LC AND IRWIN TAPE BACKUP UNIT

    PROBLEM:       Bravo 4/33 LC fails to recognize an Irwin A250EP Parallel Port
                   Tape Backup Unit.  The EZ-Tape software that is provided with
                   the unit is unable to detect the tape drive connected to the
                   parallel port.  This generates the error message "No tape
                   drive found."

    CAUSE:         The EZ-Tape software has several delay loops that are executed
                   too quickly on the Bravo 4/33 LC.

    AFFECTED
    SYSTEMS:       All Bravo 4/33 LC systems.

    SOLUTION:      By patching the software and increasing the delay loops, the
                   EZ-Tape software can run properly on the Bravo 4/33 systems.
                   These delays can be added by manipulating an environment
                   string as follows:

                               SET PPCFDC=O:12,I:18

                   This string represents the environment for the Parallel Port
                   Controller Floppy Disk Controller (PPCFDC) to have an Output
                   delay factor of 12 (O:12) and an Input delay factor of 18
                   (I:18).  These values were found to provide the best results
                   for the software to function properly.  This environment
                   string can be typed at a DOS prompt before executing the EZ-
                   Tape software or by adding this line to the AUTOEXEC.BAT file.

                   This string will not decrease the functionality of the
                   software or system.  The delay factors are only providing the
                   normal delay that would be done on systems that the software
                   was originally designed for.