OS/2 v2.1 DRIVERS
=================

This driver includes the following features:

1. Double word 32-bit PIO transfers with support for fast SCSI (10MByte/second)

2. Extended BIOS translation is supported for disk capacity larger than
   1Gigabyte.

3. Full support for all command line options.

INSTALLATION

1. Make a copy of OS/2 Diskette 1.  Delete the file IBMSCSI.ADD from this
   copy.

2. Copy the AHA152X.ADD file from the Driver diskette (OS2 subdirectory) to
   the root directory on the copy of OS/2 Diskette 1.
   (The root directory is the first directory on the diskette.)

3. Begin OS/2 installation by inserting the Installation Diskette into drive A
   and restarting the system.  When prompted to insert Diskette 1, insert the
   copy that you modified.

Exceptional Case for Toshiba-3401 CD-ROM

If you are installing OS/2 from Toshiba-3401 CD-ROM, these extra steps are
needed:

*  Proceed with installation from step 3 above.  During hard disk preparation,
   select FAT file system.

*  After the first phase of installation is complete, system will restart.
   Boot the system with DOS diskette in drive A:.  Do not let the system boot
   from hard disk.

*  Go to C:\ and make the following changes to CONFIG.SYS file in root
   directory using DOS EDIT program.

   Change  BASEDEV=AHA152X.ADD
   to      BASEDEV=AHA152X.ADD  /!SN

*  Restart the system.  Let the system boot from hard disk and proceed with
   normal installation.

COMMAND LINE USAGE

There are new command line switches to support the new features on the driver
AHA152X.ADD.

Universal Parameters

/SN - Allow synchronous negotiation (DEFAULT).
/!SN - Prevent synchronous negotiation.


Special Unit Parameters

/BOFF:t  allows the bus-off time to be set to a value between 1 and 15
         microseconds. The default value for OS/2 2.x is 4 microseconds and
         this should be used for most systems.

/BON:t   allows the bus-on time to be set to a value between 1 and 15
         microseconds.  The default value for OS/2 2.x is 7 microseconds and
         this value  should be used for most systems.

/D       Allow targets to disconnect from the SCSI bus (DEFAULT).

/!D      Prevent targets from disconnecting from the SCSI bus.

/H:x     Specifies the controller SCSI ID. A number from 0-7 replaces x.
         The default ID is 7. If you specify an invalid number, the default is
         used.

/PIO     Use programmed I/O to transfer data to/from the SCSI bus.

/Y       Enable parity checking on the SCSI bus (DEFAULT).

/!Y      Disable parity checking on the SCSI bus.