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Re: 800k disks possible at all?
In article: <4o422f$4fi@newsbf02.news.aol.com> eadeans@aol.com (EADEANS)
writes:
>
> >>Actually, I think they did it by varing the speed at which the data
> is written to the disk, depending on how far out the head is from
> the centre of the disk.
> <<
>
> This makes good sense. Apple used a similar scheme to cram over 800K on
> the 5 1/4 floppies for the original Lisa Office System computers (in
> 1983).
Weren't those "Twiggy" drives 400K? They had two notches on the disk as the
read/write heads were not above/below each other. The Lisa2 (or whatever
it was called) had 400k 3.5" disks (single sided) which were soon replaced
by the 800k double sided ones.
> Does anyone know of a way to read or create disk images from old 5 1/4
> ProDOS disks on a PC? I want to convert my old //c Appleworks stuff over &
> use it on Clarisworks. I'm also going to try an Apple IIe on Mac emulator
> under Executor (on OS/2 virtual DOS) just for fun!
Yes, but you need an original Apple II of some sort, be it a whole machine
(II,II+,//e with Super Serial Card) or a IIc or IIc+. Then get a bit of
software called ADT (for the PC) or MacADT. Check out the
comp.emulators.apple2 FAQ for more info.
> Ed.
> TeamOS2 & ClubOpenDOC
>
>
--
John.
john@klatch.demon.co.uk
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