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From: del@pilchuck.UUCP (Erik "Hugable" Lindberg)
Newsgroups: net.micro,net.micro.pc
Subject: Re: AT floppy drive in XT ???
Message-ID: <360@pilchuck.UUCP>
Date: Fri, 20-Jun-86 17:56:58 EDT
Article-I.D.: pilchuck.360
Posted: Fri Jun 20 17:56:58 1986
Date-Received: Mon, 23-Jun-86 03:27:56 EDT
References: <167@daisy.UUCP>
Distribution: net
Organization: Data I/O Corp., Redmond, WA
Lines: 21
Xref: linus net.micro:13506 net.micro.pc:8399
Summary: Won't work in the XT, sorry.

In article <167@daisy.UUCP>, misha@daisy.UUCP (Mike Umansky) writes:
> Has anybody out there tried connecting a high capacity (1.2MB) AT floppy
> drive to an XT?  I have one and would like to be able to read AT floppies
> and also have a larger capacity temporary backup medium.  Can the standard
> floppy controller communicate with the AT floppy drive without burning it
> or itself out?  If the hardware is compatible, then, I guess, all that I
> will need is to write a driver based on the AT's BIOS, is that true?

Sorry, but this won't work. The AT controller actually selects different
data rate for the 1.2MB floppy, and the XT controller does not have this
capability. Furthermore, the signal interface is different (what do you
mean 5 1/4" standard?) Note this also means that you can't even take a
XT floppy drive and put it in an AT without a special adapter. Going the
other way (AT -> XT) *might* be possible for the 360k low density drive, 
but definitely not the 1.2MB.

Another odd offshoot of this problem is that 3 1/2" drives can not be
plugged into the AT controller either, like they could on the XT. This is
strange, since DOS 3.2 now supposedly supports 3.5" drives...

Erik Lindberg   aka  del