
			UltraStor Corporation

		     Application Note (18008-002)
			       REV 2


Subject:	Installing the 3rd Floppy Drive for use under DOS.
Date:		11/21/89
----------------------------------------------------------------------

This document describes how to install the 3rd Floppy Drive on the UltraStor
Ultra-12F disk controller using the straight connection method on the floppy
cable.

This method can be used only if the drive that will be installed as the 3rd
drive has drive select jumpers DS1, DS2, DS3, DS4. Drives that are jumpered
permanently to DS2 by the manufacturer cannot be installed using this method.
The cable needed for this installation is shown below.

	--	                     --              --              --
	||---------------------------||--------------||--------------||
	||---------------------------||--------------||--------------||
	||---------------------------||--------------||-----------\/-||
	||---------------------------||--------------||-----------/\-||
	||---------------------------||--------------||--------------||  pin 1
	--                           --	             --              --

	U12F Controller		    3rd floppy	    B drive	   A drive


1.  Jumper the 3rd floppy drive to DS4.

2.  Jumper JP11 Pin 1-2 on the Ultra-12F controller.

3.  Mount the drive in an available drive bay in the computer per the
    manufacturer's instructions.

4.  Make sure that the power supply in your computer has enough power to
    support the 3rd floppy drive and connect the power cable to the 3rd drive.
    You may need a Y-cable if you have more than 4 drives (hard disk and
    floppy combined) in your system since most power supplies come with only 4
    drive power cables.

5.  Connect the 34-conductor ribbon cable to the 3rd floppy making sure that
    pin 1 of the cable aligns with pin 1 of the connector on the drive.

6.  Power up the computer and boot up the operating system. Copy DRIVER.SYS
    that comes with DOS 3.2 and above, and the 3rd floppy BIOS file
    (EXFDRV.SYS) onto your usual boot drive.



7.  Modify CONFIG.SYS by adding 2 lines shown below. 

    DEVICE=EXFDRV.SYS /1:xx
                         |
                         xx = 1  for 360KB drive
                              2  for 1.2MB drive
                              3  for 720KB drive
                              4  for 1.44MB drive

    DEVICE=DRIVER.SYS /D:2/T:aa/S:bb/H:2/F:cc
                             |    |        |
                             |    |        cc = 0 for 360KB
                             |    |             1 for 1.2MB
                             |    |             2 for 720KB
                             |    |             7 for 1.44MB
                             |    |
                             |    bb = 9 for 360KB and 720KB
                             |         15 for 1.2MB
                             |         18 for 1.44MB
                             |
                             aa = 40 for 360 KB drive
                                  80 for 1.2MB,720KB,1.44MB drives

    Refer to the DOS manual for detailed explanation on the usage of
    DRIVER.SYS.

8.  Boot up the computer again. The computer will go through the normal boot
    procedure with 2 additional sign-on messages of the 3rd floppy BIOS and
    DRIVER.SYS as follows:

    EXFDRV Vx.xx (c)Copyright ........
    Loaded External Disk Driver for Drive ??

    (where ?? is the next available drive letter assigned by DOS)

9.  The 3rd floppy is now ready to be used.

