13 Aug
2006
13 Aug
'06
10:24 p.m.
On Sun, 13 Aug 2006, vrs wrote:
I'm guestimating that once these miniaturized Rxxx and Sxxx modules are
designed, manufacturing them in the quantities required for even a single
Straight-8 would be very cheap. Now about the backplane: Is it possible
to make it with a PCB, or is wire-wrap absolutely required?
I'd guess something like 1/4 scale would be
acheivable. If you make it
too small, you'll have trouble with the user interface (as you mentioned
about the 1/12th scale IMSAI).
I agree with the quarter scale. Beyond that and one would need tweezers
or hemostats to handle the flipchips.
One could
always start small and build something simpler from the same
technology - a simple clock or something - sort of a test-drive to see
what the scope of a full processor would entail.
I'd start out by building replacements for the Rxxx and Sxxx modules, all
scaled down. (Once a few of those work, you could start in on a backplane
for them.) For testing, you just need a standard size module with
a female 9x2 right
angle connector on it, and insert the miniature card being tested. Replace
an original module in some old gear with the result, to see if you've got
things right. You could also use the technology to resurrect old gear with
missing modules :-).
That's only a little better than half-scale, though. One quarter scale
would need finer pitched connectors, which would probably be way more
expensive.
It would cost more, but I don't think it would be by very much. How about
having three rows of .1" connectors?
Another goofy idea I had (for inexpensive
interconnect) was to try to
squeeze the SMT modules down into the footprint of, say, an 18 or 20 pin
DIP. It wouldn't look much like a replica anymore, though.
Nah. From a casual browse of my catalogs, it'll cost you around 75 cents
per card/backplane connection. Doing the DIP thing would probably end up
being more than that.
--
David Griffith
dgriffi at cs.csubak.edu
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