A lot has happened over the last four weeks or so. When I put the TU60 back on the TA8E, it didn't work there either. After a bunch of weeks of troubleshooting (and finally buying some card extenders from Douglas Electronics) the TA8E / TU60 is back to working condition. The IOT decoder 7442 on the TA8E was broken and two 8640s in the TU60 were bad. It turns out that 380 and 8640 have the same pinout, so I used 380s. So tonight, for the first time in a long time, I booted CAPS-8 from the original bootable cassette that I built by hand almost four years ago now.
While waiting for my card extenders to come, I fixed up an MI8E diode bootstrap loader. I have no idea what the original diode configuration was for, but I changed the diodes to the RX01 bootstrap. Now the SW switch on my 8E does something! Of course, the MI8E was broken too, but the problem was a 2N3009 that drives the Pulse LA H line. I actually had the replacement. So, now it's the end of an era - I no longer have to fat finger a bootstrap on the 8/E. I can use the rom bootstrap loader to load the RX01 bootstrap, then run OS/8 and use the boot command there to load whatever strap I want (which at the moment is only the cassette.)
Now I need to clean up a bit, and put the TU60 back on the TA11 11/04 and try that again. At least now I know that the TU60 is good!
Lou