Path: utzoo!attcan!uunet!husc6!rutgers!gatech!gitpyr!is813cs
From: is813cs@pyr.gatech.EDU (Cris Simpson)
Newsgroups: comp.sys.ibm.pc
Subject: Re: How to notch 720kb to be 1.44mb
Message-ID: <6214@pyr.gatech.EDU>
Date: 8 Aug 88 22:57:36 GMT
References: <5930011@hpcupt1.HP.COM>
Reply-To: is813cs@pyr.UUCP (Cris Simpson)
Organization: Georgia Institute of Technology
Lines: 70

In article <5930011@hpcupt1.HP.COM> williamo@hpcupt1.HP.COM (William O'Saughnessy) writes:
>
>How to notch 3.5 720kb diskettes to be used as 1.44mb diskettes.
>
>Now for the technique.  Buy a pair of Radio Shack red handled wire
>cutters.( There's nothing magic about them.  They just worked fine
>for me.)  Use them to cut a 11/32" by 13/32" piece off the density-
>hole corner.  Do not attempt to notch the side of the floppy.
>You will just put a lot more strain on the diskette and the result
>will not be nearly as neat.  See diagram below.
>
>			 3.5 inch diskette:
>		   I                                  I
>Write Protect      I                               i---<------- Cut here.
>    Hole ------>   I o                             I  I  13/32"  
>		   I                               I  I
>		   --------------------------------I--I--------
>                                                   I  I
>						   /  \
>						   11/32"
>                                                  /\
>						  Cut
>						  here.
>
>The above is down right dangerous to your 1.44 mb drive, but if you
>like to gamble and save a little money, this is how.  Who knows
>maybe someday there will be a booth at computer swaps where they
>will use a laser to put a hole in the diskette for 50 cents per disk.





One of the biggest dangers of this is the possibility (probability)
of little pieces of plastic floating around on the mag surface, spinning
around and getting stuck  in the head. Oops!  Here's my solution.

Look into the maw of the 1.44 drive. See the pin on the right? Remember it.
Now, open computer and disconnect 1.44 drive. Slide it out. Remove 
shield to get at drive PC board. Remember that pin? Look at the back side
of it. There should be a microswitch. When the pin is pushed in, the switch
closes, going to ground.  Using a very sharp Xacto knife, cut the trace 
that goes to ground. Don't scrape it off, just separate it. Now any disk 
will appear to be 1.44. Reverse above steps to put back together.

Why did why cut and not scrape? Easy to fix w/ a touch of solder.
Can I read 720s? Yes.

Can I write 720s? I can't. But I am going to go back and short
the trace I cut with a spst switch. It will allow me to choose what I
want.

What if I screw up? sorry.

Will this void my warranty? Probably, if you were to show that unsoldered 
cut to someone working on it.   :-)

Send me mail if you have any questions.

cris





-- 
||...despair! Despair I can handle, it's the hope...    J.Cleese,Clockwise ||
Cris Simpson
                  is813cs@pyr.gatech.edu               GA Tech      Atlanta,GA
...!{akgua,allegra,amd,hplabs,ihnp4,seismo,ut-ngp}!gatech!gitpyr!is813cs