Re: Did Commodore cheat with the quad density floppies?

From: Francesco Messineo <francesco.messineo_at_gmail.com>
Date: Wed, 9 Jan 2019 12:08:59 +0100
Message-ID: <CAESs-_ydhwzu6yx-FPxFEu1c0s7rZO4E5LuL1C-_v58tiwbqew@mail.gmail.com>
On Wed, Jan 9, 2019 at 12:02 PM <silverdr@wfmh.org.pl> wrote:
>
>
> > On 2019-01-09, at 11:43, Francesco Messineo <francesco.messineo@gmail.com> wrote:
> >
> >> At least IEC still allows more than two devices ;-)
> >>
> >> But no, the IEC on the C64 is another example of CR(ippled) hardware, plus VIA-bug workaround ridden implementation. Its big brother GPIB, while predating both, wasn't bad though.
> >
> > Yes it was slow, but I couldn't think about a better compromise,
> > really.
>
> The major issue was actually the speed - not really of the bus but of the 1541 implementation with 6522 software workarounds making the bus look worse than it really was. Common thing was to add at least the parallel connection to 1541, bringing it somewhat closer to the original GPIB. And yes - it still allowed more than two devices and obviously not only the floppy drives.

Yes, that was due to a bug in the 6522 chip. And sure, one of the
first things that I purchased when I could,  was the speeddos mod,
even if I needed to go back to plain IEC speed whenever I wanted to
plug the super-fast 300 bps user port modem :)

Frank
Received on 2019-01-09 13:00:32

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