Date   : Tue, 23 Mar 2010 21:48:43 +0100
From   : anders.carlsson@... (Anders Carlsson)
Subject: Re-using floppies

David Alan Gilbert wrote:

> That's the 2nd time I've seen reference to 100 tpi discs - can
> you give some more information?

Well, not really. I have come across a bunch of 100 tpi floppy disks
and could probably look up some Commodore (PET) hardcore users who
can elaborate on the difference. But the manuals actually say 100 tpi,
perhaps the 96 tpi ones were not really established at that time.

It is correct that all Commodore drives are "intelligent" devices, in
that they have one or two 6502's, a few 6522's, some 6532, RAM and ROM.
For most tasks you can issue a higher level command and the drive will
take care of the rest. It means the computer doesn't need a floppy drive
controller, it only needs some I/O port.

Actually a bunch of non-Commodore computers and even Emu (?) synthesizers
are known to have been interfaced with 1541 type drives because of their
built-in intelligence.

> I'd love to know what else used 100tpi ?

Hm.. perhaps TRS-80, Vector Graphic, Victor/Sirius etc?

Best regards

-- 
Anders Carlsson