Re: Question

[spec@vax2.concordia.ca (Mitchell Spector)]

In article tim@buffnet.net (Tim) writes...

>I hope this question doesn't make me sound *too* dumb, but here goes:
>
>I no longer have any 800k 3.5" floppies for my IIgs.  The only ones I can
>still find in this area are the 1.4 megabyte disks with the notch on both
>corners of the disk.

    Those will work exactly like standard 800K double density disks--you
can format/read/write and even boot from them with no problem. Rumour has
it double density 3.5 floppies are merely 1.44 MB disks that did not meet
high quality testing standards (this would explain why some 800K disks
have an imprint where the HD detection notch is normally found).

    The only catch is, what happens in the long term? Many believe that
the data will degrade after a short period of time, although from my
own personal experience I found that not to be a problem (I have a few
high density that were formatted to 800K over 5 years ago, yet the data
on them has remained fully intact). I'm still a little cautious about
it though, I use real double density disks for permanent storage and
save any 1.44 MB disks for my SuperDrive.

>If I cover up the second notch on the left-hand side, will I have an 800k
>disk that I can use in my IIgs?

    This is only necessary if you plan on inserting the disk into a
high density drive (e.g. a Macintosh or Apple II with SuperDrive).
An 800K drive will just see it as a regular floppy disk--notch or
no notch. Incidentally, I'm just stating facts here, not making a
recommendation that people out there use HD disks in a DD drive
(so please don't flame me, like last time this came up. ;-)

>The reason I ask is because I remember back when I used to use the 5.25"
>floppies, I used to take a razor-blade and make a second notch on the
>other side of the disk.  After doing so, I could write on the back side of
>the disk.  When I covered up the notch, of course, it was write-protected
>again.  I was wondering if this works with my 3.5" floppies similarly.

    Well you can certainly poke a hole through the upper left corner of
a double density 3.5 disk, tricking a high density drive into thinking
it is a 1.44 MB disk (in fact people used to do this when disks were
still expensive). However I really wouldn't recommend doing it, this
is far more risky than doing the opposite (using HD 3.5 as DD 3.5).

    Speaking of 5.25 disks, under no circumstances will a high density
5.25" diskette work in a double density drive. If you attempt to even
format one, the drive will just grind and report errors throughout the
entire process. The magnetic coating is very different.

Mitchell Spector
spec@vax2.concordia.ca