Tuesday, October 25, 2016

RC2016/10 -- Wiring Complete

October is winding-down, and with it the Retrochallenge RC2016/10 event. As we round the last turn and start the sprint to the finish, how are things going? Well, not too bad -- the birth of my new COSMAC ELF is coming along well... ;-)

Wiring Wrap-Up

As predicted, learning the skill of wire wrapping was not without its hardships. I think I have achieved basic competency at this lost art, but I am still far from comfortable with the technique. Just as I settle into the groove of things, usually I will hit a run of a dozen premature wire breaks in a row or something equally frustrating to the builder. Nevertheless, the directions provided in the VCF ELF kit and a little patience and diligence have allowed me to complete the basic wiring for the new machine.

Just before wiring the toggle switches...

Pre-Flight Check-Up

With the wiring completed, it is tempting to charge ahead to power-up! However, prudence demands some basic testing be done, lest one enjoys the smell of "magic smoke". Using the audible continuity checker on a multimeter, I ensured that the pins at each end of every node were connected. Testing between the outside pins of a node is a shortcut to prevent walking pin-to-pin testing for continuity at ever point along the way. This shortcut should be fine...hopefully... In my hubris, I have neglected to do any sort of extensive checking for short-circuits -- wish me luck?


At this point, there is little left to do but to stuff the parts into the sockets on the board and apply power. Considering the risk of shedding tears at that point, I may delay a day or two just to ensure that I have had a chance to remember anything I might have forgotten! I need to line-up some simple ELF programs to use for testing as well. But really, at some point we must proceed...

There is only so much time left in this competition and little excuse not to proceed at least until power-up. Whether that turns out well or not, I suspect that I will see this project through one way or another. If you are reading this, then I imagine that you want to see this ELF in action...well, stay tuned!


  1. Great news, John! I wish you luck! :)

  2. turn it on. turn it on. Turn it on!

  3. turn it on. turn it on. Turn it on!