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Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ukma!xanth!ames!haven!umbc3!wolf.umbc.edu!alex
From: alex@wolf.umbc.edu (Alex Crain)
Newsgroups: unix-pc.general,comp.sys.att
Subject: Re: 3.5" floppy disk revisited on the UNIX pc ...
Keywords: 3.5" floppy, 720K, more space, backups
Message-ID: <1990@umbc3.UMBC.EDU>
Date: 4 May 89 21:09:59 GMT
References: <695@icus.islp.ny.us> <115@pbhacker.UUCP>
Sender: newspost@umbc3.UMBC.EDU
Reply-To: alex@wolf.umbc.edu.UUCP (Alex Crain)
Organization: University of Maryland Baltimore Co.
Lines: 27

In article <115@pbhacker.UUCP> tlh@pbhacker.UUCP (PUT YOUR NAME HERE) writes:

>Instead of using a mechanical switch, why not change the system's device
>drivers to make use of the 4th LED as a switch.  You would still only be able
>to access one drive at a time, but you could do it remotely and not have to
>manually flip a switch.  Here's how it might be done.. if the 5 1/4 drive
>device file is accessed, the disk device driver would turn "off" the fourth
>LED and (with some minor main-board modifications) this would cause a physical
>connection to be made with the 5 1/4 drive.  If the 3.5 device file is accessed,
>the exact opposite would occur.  comments?

	How come nobody thought of this before? This is a *GREAT*
idea! Somebody would have to write a quickie driver for the two
disks that would use a semaphore to handle bus arbitration on the
cable during floppy I/O, and you would probably want to prohibit
making either disk a mountable file system (managing that level
of bus activity would be pretty fierce), but it would certainly
be nice.




		
					:alex
Alex Crain
Systems Programmer			alex@umbc3.umbc.edu
Univ Md Baltimore County		umbc3.umbc.edu!nerwin!alex