4 Mar
2014
4 Mar
'14
2:26 p.m.
On Tue, Mar 4, 2014 at 3:05 PM, Marc Howard <cramcram at gmail.com> wrote:
I just don't want to see someone doing a good deed
get burned. Another
suggestion is that as long as he's doing this it should probably be a 4
layer board. Doesn't increase the price that much and does wonders for
signal integrity.
Why would four layers be a concern, though? All of the boards in my PDP-8/E
and /M boards are two-layer, with manually routed traces and no ground
plane.
It would make sense to add an auto-loader, in my opinion. I have a board
that works well, made by Tennecomp. It can be configured to work with an
external push-button or the SW switch. The original design calls for a
1702A, which I think would be just a bit too difficult for most people to
reprogram these days. My second board has been white-wired to accept a
2716. I'm thinking for ease of use, a socketed EEPROM might be good, but
another neat idea might be an in-circuit serial reprogrammable device.
If folks are interested, I'll see about reverse engineering the board. I
count 34 ICs on the board, along with three transistors, five diodes, and
various resistors and capacitors. Probably could be really reduced with a
PAL Or just put it all on a microcontroller.
Kyle