The PDP 8/s is now completely running. It ran for over 10 hours (today and yesterday) with no bugs - not flaky! yes. The high speed reader is *finally* aligned and working well. The 8/s is running all kinds of MAINDEC programs today before the real "binary loader" is run. BTW: The PDP 8/S CPU has 1001 transistors in it (999 if you don't include the two transistors on the core stack) A few things amaze me about this machine. First, the signals are so *clean* on the scope - No noise or rounded/poor waveforms I am use to seeing on TTL units (slower switching rate obviously). Second is the PC0 paper tape drive. DEC managed to get 300 cps through this unit by merely strobing the data off the optical sensors DIRECTLY onto the negibus (no flip flops!)... A real fun treat to align as the punched holes have to appear directly over the sensors half way through the feed. Weirdest thing I have ever seen. The D/A converter is working well and the A/D unit has also been tested. I am hooking up an ASR 33 to it tomorrow so I can start running some *serious* programs on it. Core memory and power supplies have been tuned. I am going to put up a website for it by the end of the week with pictures of this unit. Hopefully a telnet/camera link to it by the end of the month. In total it had: One bad connection on the W108 board (near core - caused from heat) One bad connection on SY R133 board - 2 hours to find that problem - serial everything.. ugghh..(again, near core - heat) One bad transistor on a 302 triple flip flop (my fault, I was actually tired enough to try a spare module...not the way to fix this machine) Alignment on the reader was out by a hair to cause poor data. about 10 hours reading/ 10 hours working hand on. I would like to thank the folks in this group who gave me advice about their experiences with transistor computers which saved me many hours of work and helped to make sure this unit would not be buggy. ----- I am trimming my collection to focus on the real pieces I want to collect. I have a CTS11-J backplane and cards for anyone here who wants to trade anything for it or just plainly really needs it. I also have an H213 core stack if anyone would like to trade some broken/not broken R XXX series flip chips for it. I am going back into storage over the next couple of weeks and should have quite a bit of stuff to find good homes both here and on Ebay. john