TSIA :) I was skimming through the 11/34 manuals, and some confusion about the termination of that system made me re-read through the M9312 manual. Something doesn't seem right and points to me not understanding something. I seek enlightenment from the list. As I've understood things, you have to terminate both ends of the unibus. Let's say you're dealing with an 11/34 with no expansion backplanes (ie. just a DD11-PK). According to the 11/34 manual you put the M9302 terminator in slot 9AB. That makes sense, it's the unibus out. All the other AB slots are MUD (except slot 1AB, and we'll get to THAT in a moment). So about that other end of the bus now! The manual states you need a M9301 bootstrap/terminator just after the processor (typically, it may be further down if you have the FP and/or Cache options). That also makes sense to me, gotta terminate that "near" bus end. I had a M9302, but I didn't have a M9301. I wondered if I could use a M9312 in place of the M9301. So... I skimmed the M9312 bootstrap/terminator manual, and sure enough, it definitely talks about being able to use the M9312 instead of a M9301 in a processor that "has bus termination built into the cpu such as the 11/04 & 11/34". It even says that you must set the jumpers on the M9312 to remove it's termination capability, because in these specific processors the cpu provides bus termination. Ok, great. I can use my M9312 in place of the M9301 long as I jumper it as described. But... now wait a second! This gives rise to my first question. If the cpu is providing termination, and if you are going to use a M9312 on the near side you have to "jumper off" the M9312's termination ability... then WHY is a M9301 called a "bootstrap TERMINATOR". It must NOT be a terminator, just a bootstrap rom card. Right? It seems to me that if the cpu is providing the termination on the near end, that it is always doing so. Not JUST when you pull out the 9301 and put in the 9312. What gives there? That gives rise to my second question. IF the cpu is providing unibus termination on the one side... why can't you jumper the M9312 to provide bus termination and just put it in slot 9AB? You would get the other end (unibus out) terminated AND get your boot roms as well. This way the M9312 would replace both the 9301 AND the 9302. A few people I mentioned this to said you can't do that. But given the above... it seems logical. What's the scoop here? Clarification is much appreciated! Jay West