[Coco] Glenside IDE + Multi-Pak + HDB-DOS

Mark J. Blair nf6x at nf6x.net
Sun Sep 11 21:28:18 EDT 2016

> On Sep 11, 2016, at 18:07, David Ladd <davidwladd at gmail.com> wrote:
> Robert,
> I also thought if you plugged a real floppy controller into the Glenside
> IDE board you also had to make sure you patched the floppy controllers
> logic to only respond to the $FF4x range and ignore the $FF5x?

Maybe that's the reason for the Glenside IDE supporting a $FF7x base? I think that the floppy controllers just uses the SCS signal for controller chip address decoding, so it would be necessary to splice in extra logic to decode into a smaller window.

So I gather that:

1) The Glenside IDE $FF5x base address is for MPI compatibility.

2) The Glenside IDE $FF7x base address is for non-MPI, FDC-on-Y-cable compatibility.

3) With neither an MPI nor an FDC, the base address doesn't really matter.

4) There may be a separate timing issue in HDB-DOS + Glenside-IDE + MPI.

It looks like using SCS in my new widget doesn't decrease IO count enough to let me use a smaller CPLD. So alternately, maybe I should have a provision to disable the EEPROM in case anybody wants to use it with an FDC on a Y cable? Or maybe I'm over-thinking things?

Mark J. Blair, NF6X <nf6x at nf6x.net>

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