Path: utzoo!utgpu!attcan!uunet!husc6!bloom-beacon!mit-eddie!ll-xn!ames!amdahl!pacbell!att!whuts!homxb!homxc!rps
From: rps@homxc.UUCP (R.SHARPLES)
Newsgroups: comp.sys.ibm.pc
Subject: Re: How to notch 720kb to be 1.44mb
Summary: Another approach
Message-ID: <2976@homxc.UUCP>
Date: 8 Aug 88 12:53:51 GMT
References: <5930011@hpcupt1.HP.COM>
Organization: AT&T Bell Laboratories, Holmdel
Lines: 49

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.
> 
> If you are tired of paying $4.70 per diskette for 1.44mb diskettes 
> when you can get 720kb disks for $1.30, you might try this technique
> for notching 720kb to make them 1.44mb.  This techique is dangerous,
> in that it could wipe out your 1.44mb drive.  I tore apart a defective
> disk and saw that there is a protective ridge that forms a 90%
> seal between where you notch the disk and the actual media.
> 
> 	    USER   BEWARE !! !! !! 
> 
> 	    YOU ARE RISKING YOUR 1.44mb DRIVE   !!  !! !!
> 
> Now for the technique.
...
>

The above technique was to essentially cut off the upper left hand corner
of the disk.  This, however, is not necessary.  You can achieve the same
results by drilling a hole in the upper left corner of the disk.  Specifically,
holding the disk with the shutter at the bottom (towards you) and the hub down,
you should drill a 3/16" hole at precisely 3/16" in from the left edge and 
11/32" down from the top.  There is an interior wall that surrounds the 
circular media that separates it from the corners so no plastic shavings 
will get into the media.  Be careful that no shavings are left over to drop
into your drive.

I have tried this and it works.  HOWEVER, REMEMBER THAT 720K DISKS ARE NOT
MADE TO OPERATE AT 1.44 MEG RELIABLY, AND YOU WILL PROBABLY LOSE DATA
TO SECTOR READ ERRORS.  I wouldn't back up my harddisk to these things.  I have
done this to one of these disks and have copied a whole bunch of data to it.
Every day I am going to run Norton's DISKTEST on it to see if errors develop.
The disk I am using is a Storage Master Brand.  I'll let the net know what
happens.

OBVIOUSLY THERE ARE NO WARRENTIES ABOUT THIS PROCEEDURE!!!!!  YOU ARE ON YOUR
OWN.  IF YOU DESTROY YOU FLOPPY DISKS, DRIVE, HARDDISK, COMPUTER OR ANY THING
ELSE, I DON'T CARE.  I AM NOT RESPONSIBLE.

Russ Sharples
homxc!rps

NOTE:

The above in NO WAY reflects the opinions of AT&T.
These opinions are my own and the results of un-scientific and 
highly irregular analysis methods.