Path: utzoo!mnetor!uunet!husc6!rutgers!clyde!cbosgd!mandrill!neoucom!wtm
From: wtm@neoucom.UUCP (Bill Mayhew)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Formatting 720Kb 3.5" disks on XT clone
Message-ID: <991@neoucom.UUCP>
Date: 7 Feb 88 02:47:25 GMT
References: <3814@umn-cs.cs.umn.edu> <3824@cbterra.ATT.COM>
Organization: Northeastern Ohio Universities College of Medicine
Lines: 40
Summary: How to make a 1.44 meg floppy work on an AT  (here's how).


Recently, I had to get a 1.44 meg Sony 3.5 inch drive to work on
an AST AT look-alike machine.

Dang frustrating, as has been noted on this net.

1.  Use [MS]DOS 3.3.  ver. 3.2 might work, but I used 3.3

2.  Install the drive as floppy unit 1 (B:).  I assume that you
    are going to retain the original 1.2 meg drive as A:

3.  The AST's Phoenix BIOS has a built-in CMOS RAM setup program
    that is accessed through CTRL-RSHIFT-ALT (or something simialr;
    I don't recall off hand).

4.  Edit your CONFIG.SYS file to set up parameters for your drive.
    Unfortunately, there isn't any real nice pretty way to get the
    drive to user-transparently switch back 'n forth between 720K
    and 1.44 meg.  What you need to do is set the DRIVPARM for 720K
    and then use the DRIVER.SYS device driver to handle the 1.44
    meg operation.  What happens is that DRIVER.SYS will map the
    1.44 meg operation into the first available letter after your
    fixed disk:

    This is from memory, so consult your DOS manual to double
    check.
    <<contents of config.sys>>

    DRIVPARM=/D1 /T80 /H2 /S9 /U1
    DEVICE=DRIVER.SYS /D1 /T80 /H2 /S18 /U1
					 ^
					 |
		     this is the parameter I don't remember
		     you need to indicate to use the drive
		     media change line.


The above worked for me, your mileage may vary.

--Bill