11 Sep
2012
11 Sep
'12
10:45 a.m.
that jig was later to become known as a nibble notcher. I still got mine.
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On Tue, Sep 11, 2012 8:27 AM PDT Fred Cisin wrote:
On Mon, 10 Sep 2012, Jose carlos Valle wrote:
I am curator of Museu do Computador, Brazil ,
Jose Carlos Valle
Thera are 2 kinds of floppies an 360 kb and another in High density 1.2 Mb.
But, with a tool, I cut a small hole at left floppy and I double the
floppy. goes to 720 at total
I have that tool in my Museu.
Are you talking about a jig to modify a single sided diskette, so that you
can flip it over and use the other side as a single sided diskette?
(called a "flippy" disk)
Are you just punching an additional write-protect notch (suitable
for Apple, Commodore, Atari) or are you punching an additional set of
index hole access holes?
The first such jig that I'm aware of was sold by Don? French.
(sheet metal with tabs to hold the disk against)
The second one was the Berkeley Microcomputer Flip-Jig.
(plexiglass pocket jig)
--
Grumpy Ol' Fred cisin at xenosoft.com 
11 Sep
11 Sep
11:04 a.m.
On Tue, 11 Sep 2012, Chris Tofu wrote:
that jig was later to become known as a nibble
notcher. I still got mine.
"nibble notcher" only did the write protect notch, therefore only suitable
for machines that did not use the index sensor, such as Apple ][,
Commodore, Atari.
The two that I mentioned also marked the jacket for punching a set of
index sensor access holes (for use with TRS80, 5150 160K,180K, etc.)
The Berkeley Microcomputer Flip-Jig was also available for 8" diskettes,
which had a different index hole position for SS V DS
NB: For Apple 5.25" disks, I specify ][, to avoid confusion with Lisa.
In addition, later on, there were punches for punching a density hole in
720K 3.5" to be able to turn a good 720K diskette into a marginal 1.4M,
although SOME machines, including some PS/2 models (NOT SONY PS2!), did
not use the sensor and would happily format 720K diskettes to 1.4M and
confuse other machines.
--
Grumpy Ol' Fred cisin at xenosoft.com
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