russian PDP-11 like K1801BM2 CPU Startup reading w/o address?

Exactly why I used a variable resistor there. I don't see how this makes it a poor design. Ah. It's a poor design under certain assumptions about its intended (anticipated, whatever) use. Yes, it is. Fortunately, the kind of use you appear to be assuming was not the kind of use I put it to. Indeed, it would almost be fair to say I didn't put it to _any_ use per se; it was not done because I needed an oscillator for some other use, but rather was done as an experiment, to see if I understood RC phase-shift oscillators well enough to toss one together and have it work. As such, it did a good job in its intended use: because of it, I (think I) have a significantly better handle on the benefits and problems of such things than I did before I built and played with it. (I doubtless could have even better knowledge if I'd muddled about with it and its kin more. If I seemed likely to need such knowledge, I would; what I did has, for now at least, satisfied the desire that led me to do it.) On the one hand, that feels right. On the other, I'm considering an AGC circuit that doesn't use a bulb, but instead uses a FET as a variable resistor, and trying to figure out where it's got anything nonlinear in it (assuming the amplifier is running class A). Doesn't sound familiar to me, for what that may be worth. /~\ The ASCII Mouse \ / Ribbon Campaign X Against HTML mouse at rodents-montreal.org / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B