11/45 RTC

Tony wrote... Nope, standard 110v singlephase outlet. I think something is up with my test cable. I'm going to double check it tomorrow. I do know that I set a function generator on 50hz and connected my freq counter to it. It registered right on 50hz. I moved the freq counter to the /45 and got about 189hz on CD1. That just seems wrong. I connected my scope to the function generator set at the same 50 hz and the scope picked it up sharp at 50hz (scope does measurement). I moved it to the /45 and got odd readings, around 189hz. Here's something else... on the function generator, the 50hz clock was square and very clean. It also had a stable display. When looking at the trace on the /45, the rise and fall of the square were noticeablely sloped, not square. Also, it's like it was triggering right... because the square image seemed to alternate between two traces 90 degrees out of phase (1/2 step back). Made it hard to measure the period. I do not have DL11-W prints alas. Maybe I should start from the beginning and re-explain the problem as I percieve it. The machine boots xxdp+ v1.0 and 2.5 just fine. However, when I try to boot RT11, the lights flicker and the disk flickers for about 10 seconds, and then the system just halts. Because of the fact the system can read and write full disk packs using VTserver, I kinda doubt there is a major read/write problem with the drive. I am GUESSING that what is happening is that xxdp does not use interrupts for anything, nor does vtserver. My GUESS is that RT11 does, and that there is something wrong with interrupts on my machine. I am GUESSING that at some point in the boot process of RT11 it tries to use interrupts and thus my machine just dies there. I centered on the LTC as a possible route to investigate for two reasons - one, I was under the impression that the LTC signal had to be present for interrupts to work, and if it wasn't, I'd get this behaviour, and two - because when I run the diagnostic program for the DL11-W, it specifically complains about the LTC part of the DL11-W with "Bit 7 never sets". Sooooo long story short, I wanted to make sure the LTC and interrupts were working, then try rebooting RT11 and see if that was the issue. Bear in mind I have three DL11-W cards. I guess it's possible, but I find it hard to believe they are all bad (although they do fail the diagnostic in different ways). I've also tried several different RL11 controllers, and I've triple checked the NPG jumpers and grant cards. Maybe I should be looking in a different direction. I am going to go back and run the trap and interrupt tests tomorrow, I believe the machine fails the interrupt test. Jay