                    *********************************************
                    *                                           *
                    *    ASPI4OS2.SYS                           *
                    *    OS/2 SCSI Manager for the AHA-1x4x     *
                    *    Functional Overview                    *
                    *    Tom Shea   3/27/89                     *
                    *    OS/2 Version 1.1                       *
                    *                                           *
                    *********************************************
            
            Introduction:
            
            ASPI4OS2.SYS is an installable device driver providing 
            a generic multitasking interface to the AHA-154x line of
            host adapters.  Any SCSI device driver can ATTACH to this 
            SCSI Manager to pass requests to the SCSI bus through the 
            Adaptec SCSI programming interface.  For more 
            information on the interface between the SCSI drivers and 
            the SCSI manager refer to the Adaptec OS/2 SCSI Programming 
            Interface Specification.  

            In order to support booting and ROM BIOS supported SCSI drives,
            the SCSI manager will often be included in the DISK01
            base driver provided in an OEM release of OS/2.  The
            installable version is necessary when there is no base SCSI
            support.  If there is base support for SCSI, loading the
            installable version will result in the de-installation of
            the base version and the re-routing of all SCSI requests to
            the Installable SCSI manager.  As long as the base version
            is sufficient to get the system booted, updates and 
            improvements to the SCSI manager can be incorporated into an 
            installable version without affecting the OEM's OS/2 release.
            
            Implementation:

            To load the SCSI manager, the following line should appear
            in the config.sys BEFORE any SCSI device drivers:

                DEVICE = [path] ASPI4OS2.SYS [Options]

            PATH refers to the location in the filesytem of the SCSIMGR.SYS
            file.

            OPTIONS refers to a combination of command line options.
            The possibilities are listed below:
        
                /D - Display informational messages during initialization.
		This flag is useful when there is some sort of problem 
		getting the driver to load as expected.

		/L - Support SCSI LUNs other than zero.  This flag informs
		the SCSI manager that LUNs other than zero should be
		supported.                  
                
                
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