williamo@hpcupt1.HP.COM (William O'Saughnessy) (08/05/88)
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. 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 media guard I I
I I slide I I
I -------------------- I
I I
I I
I I
I I
I O I
I I
I I
I I
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.
As always no warranties are implied or given for any of the above
information. Oh, another note, you may want to test this on your
brand of diskettes. Some may have a tendency to forget after a
few days when recorded at the higher density.
Feel free to repost this info on any other bulletin board.
rps@homxc.UUCP (R.SHARPLES) (08/08/88)
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.
is813cs@pyr.gatech.EDU (Cris Simpson) (08/09/88)
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
pm@harry.CES.CWRU.Edu (Prabhaker Mateti) (08/11/88)
I have successfully used several 720k diskettes as 1.44Mb ones. However,
format will show several k worth of bad sectors.
To make the hole, use a hot soldering iron and carefully shave off
the excess melt from both sides of the diskette. This is far easier,
if a little smellier, than drilling.
prabhaker mateti, case western reserve university, cleveland, oh 44106
{decvax,cbosgd,sun}!mandrill!pm pm@alpha.ces.cwru.edu (216) 368-2816