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From: rick@crowbar.aux.apple.com (Rick Auricchio)
Newsgroups: comp.unix.aux
Subject: Re: A/UX 2.0.1 use of 800K drives
Message-ID: <13390@goofy.Apple.COM>
Date: 7 May 91 21:48:04 GMT
References: <1991May5.011113.462@skbat.csc.ti.com>
Sender: usenet@Apple.COM
Lines: 31

dittman@skbat.csc.ti.com (Eric Dittman) writes:

>My Mac IIfx has two floppies.  d0 (the one one the right) is an FDHD drive,
>and d1 is an 800K drive.  A/UX 2.0 and 2.0.1 both say d1 is a 400K drive and
>is therefore unusable.  Why is this?

    Two bugs are at work here, but they're ONLY ON THE IIfx.

	1) On a Mac IIfx, the driver incorrectly identifies the drive as
	   a 400K drive, and claims it's unusable since 400K drive hardware
	   isn't supported on the Mac II series systems.

	   If you insert a blank floppy, however, you CAN format it, but
	   only as a 400K single-sided floppy.  Thus the drive is still
	   usable as a 400K drive, to a certain extent.
	
	2) A second bug allows you to correctly read and write 800K floppies,
	   provided they've already got data on them (i.e. you don't have to
	   format them).  This "loophole" shouldn't exist, but rest assured
	   the I/O is getting done correctly anyway.

    
    Conclusion: You can still read/write existing 800K floppies even though
    the driver says you can't.  The future fix will be to properly report
    the drive as 800K and format floppies appropriately.
--
--
Rick Auricchio	 rick@apple.COM 	 Mooney N894AR    	 (408) 974-4227
Apple Computer Inc, A/UX Engineering,10300 Bubb Rd, MS 50-UX Cupertino CA 95014
		Work is for people who don't know how to fly.
My opinion is my own. My employer? They use a windsock and a fire extinguisher.