The 18up5 board has been tested, and is working as expected. PIPBUG is running at 4800 board, which is a pleasant increase over the original 110.
The PIPBUG socket was tested by building a second board with both sets of pins.
Fun fact: my original 2650 board (back in 1978) was connected via 20mA current loop to a Model 15 teletype running at 45.45 baud. I used a special monitor ROM called BAUDBUG that was compatible with PIPBUG, but used Baudot instead of ASCII.
I have several boards left over from the original order of ten. Please email me at firstname.lastname@example.org if you would like to purchase one. Cost is $12 plus shipping. I can add a 2716 with PIPBUG 300/4800 for an extra $5 each, and I have a small number of the 1MHz crystal oscillators for another $5 each. I’ll throw in a generic USB to serial converter with every board purchased.
Full instructions on building the board, including the circuit and parts lists, can be downloaded here