I occasionally check this forum and only Now found this thread. I follow regularly on YouTube. Still working on My Big E. With only a few hours a week it takes awhile, plus all the mistakes requiring redoing the parts. This has prompted me to return to building circuit boards. I tried the new method of toner transfer but couldn't get that to wok at all. With what's available now I went back to using the photoresist method, especially since software now allows a person to design the circuit and the layout function has the capability of auto-routing. It eliminates mistakes in the design and layout. It used to be, years ago, you had to lay out the patterns on a transparent sheet and hope no mistakes and then take it to a lithographer to make a negative so you could expose the photoresist. Now I can just do it all in software, print it out on transparency and its ready to go. Not long ago I found what seems to be the original circuits for the TMP Enterprise. What makes me wonder about the authenticity is there were a number of errors on the schematic. Mostly pin numbers. The circuit used some components that were Very difficult to find and I had to order a batch of some from China. The hardest to find was the LM3909 Strobe chip. I have all the parts for that board now. The board layout I have now has wiring connections scattered all over the board. This will make it a mess wiring. I am considering using cable connection on the edges of the board. They way it is designed it will be much more difficult for only a two-sided board, 4X6. Doing all this has delayed the building of the Big E.