25 Jun
2015
25 Jun
'15
4:10 p.m.
On Thu, Jun 25, 2015 at 10:22 AM, Vincent Slyngstad <
v.slyngstad at frontier.com> wrote:
Please correct me if I'm talking complete
bulls**t. This is all
The easy way to do this is to make one board with a small CPLD connected to
all the pins and program it to match the logic of the card you are
emulating. That way you can have a couple of hundred boards made up for
you at a reasonable cost that are all the same but ends up with different
functionality. Just stick a label on the handle to tell what the card was
programmed as.
I don't think you would have heat issues unless you actually tried to use
the original circuits.
The Straight 8 logic uses pulses for some things instead of levels making
it not really compatible with more modern logic. At least not a direct
replacement. The later models would be better targets. An I for example
might be the best choice.
You can't shrink the size of the Front Panel because the switch spacing is
already just a little narrow for people with large fingers. It would be
better to make it a little oversize in fact. I don't have large hands and
it would still be better for me if the spacing was slightly wider.
--
Doug Ingraham
PDP-8 SN 1175
new to me.
The only other concern I've had during my thought experiments
along this line related again to the current/power involved. The
device is likely to become difficult to cool if you achieve a 4X
volume reduction.
Oh, and I guess the nightmare of soldering many thousands of
surface mount discretes and transistors to manufacture such a
thing.