lördag 24 mars 2018 skrev Douglas Taylor via cctalk <cctalk@classiccmp.org>:
> I was trying to put together a minimal PDP-11/03 using a quad width M7264 > CPU and got nothing, no ODT prompt. I'm not sure the board is working. > > Searching the internet I came across this page which described a M7264 CPU > board with a 'bad' MICROM > > http://www.datormuseum.se/computers/digital-equipment-corporation/qbus > > Quoting the page; "Using a logic analyser showed that the MICROM without > label is not behaving well." I guess I wrote that a couple of years ago. If I remember correctly the way I did research into this was to attach a 40 pin DIP clip connected to my logic snalyzer on on the various MICROM chips and there were no activity at all when the board got out of RESET. Then I removed one chip at a time to see if there were any difference. This particular chip made a difference. After removing it there were busactivity. I have not yet got around trying with -3.9V Bias chips to see if that make the board run better. If your board is the later E etch then it has 3.9V bias and you could directly use chips from a KD11-HA board. > > Anyone know how a logic analyser would be used to determine this? Other > hints to debug this board? > > Doug /Mattis
