[Coco] Multipak redesign/replacement

[Andrew]

While I can't help with the design or such, I would be willing to help 
test any resulting system, if needed.

That said, what I would like to see for a new MPI would be something 
more akin to the few "backplane" systems that were available back in the 
day in the pages of the Rainbow and elsewhere (alas, I was a kid, and 
such a backplane was out of the question to my parents). I would, 
though, change things up slightly.

Instead of orienting the paks vertically, as in a standard MPI, I would 
rather that they were oriented on their sides; think of the current MPI, 
with the paks vertical, then rotate the packs 90 degrees clockwise, edge 
connector toward the cartridge slot.

There would have to be some kind of vertical interface plane for the 
slot connectors; probably all the needed electronics could be fit on a 
2-sided board (heck, maybe on one side using SMT components). There 
would have to be some kind of extra mechanical support or such for the 
vertical board, but I think it would be doable. An alternative 
arrangement might be to have the same orientation, but the edge 
connectors facing toward the rear of the CoCo (label sides of the paks 
to the front).

The nice thing about such an arrangement would be that you wouldn't have 
tall packs sticking up so far (like the original RS-232 pak - or the 
older floppy drive controllers); in fact, since all paks are the same 
width, that's the maximum height they would be above the level of the 
CoCo. If a cable connection is doable with such an arrangement, all the 
better.

Finally - a potential thing to do might be to put a microcontroller (or 
something) on each end to buffer the I/O lines and translate the signals 
to high-speed serial (maybe USB?) - so that a thinner (and longer) cable 
between the CoCo and new MPI could be used (though I realize that such a 
solution likely has major pitfalls of its own).

-- 
Andrew L. Ayers
Glendale, Arizona
http://www.phoenixgarage.org/