Problems with 8/A Programmer's Panel - test-drb@ccmp.vtda.org

9 Sep 2015

...
 Not sure what you mean by membrane keypad. My front
panels certainly
have real buttons, which makes a clicking noise and feeling when I press
them. But maybe I'm confused and there is some membrane behind the keys
or something?

Johnny 
That's my mistake. I've never actually seen or touched a DKC8-AA panel, just 
pictures of them in the manual :)
Hoping to acquire one since I am trying to do other things with the 8/A than 
keep debugging its hardware! (such as getting Dumprest working for RL02).

...
 The 74f parts may be too fast. Try adding damping
resistors (10 to 30 ohms) 
in series with the outputs to slow things down or just switch to 74ls

Joe 
Thanks for the tip. That is what I was implying, not sure I said so 
explicitly :)
But adding twelve resistors which may or may not fix the problem, and 
hacking up my board is not an attractive thought... but neither is changing 
three 20-pin unsocketed DIPs without proper desoldering equipment. Guess I 
should have used sockets in a prototype!
Besides, the board really does need redoing with proper power and ground 
plane management.

-Charles