Hi! On Tue, 2023-12-19 02:19:39 +0100, Johnny Billquist <bqt%softjar.se@localhost> wrote: > On 2023-12-18 18:50, Maciej W. Rozycki wrote: > > On Mon, 18 Dec 2023, Johnny Billquist wrote: > > > For the KA46 (and *only* the KA46), we are using some other mechanism, which I > > > haven't really dug into, to get some higher precision time when reading out > > > time. But let's ignore that platform for the moment. We have people with > > > various machines, and simulations, which have the time problem. And most are > > > not KA46. As far as I see, KA46 is merely the 4000/60. > > > > Conversely what I have been concerned with is incorrect operation with > > actual hardware, and then this specific one. > > Did anyone actually report results running on a 4000/60? Personally, I've > been running on a 4000/90, where time is not working well. But that one > would be depending on the ICR. But I haven't checked if it actually do have > a proper ICR. Does anyone know? I have a 4000/96 around (with PiSCSI emulating a CDROM and a disk), but could easily fetch a /60 (or some smaller 3100 model) from storage. Probably after the actual christmas days, I'd join with testing, as soon as I know what's _actually_ needed to be tested. > For most any VAX, the high resolution time comes from reading the ICR. > Looking at the code, it seems in general to be reasonable, but I do have > some questions about it. > But clearly machines are having issues, which leads to the suspicion that > something in broken in that bit of code anyway. What also comes to mind is that I'd probably try to measure some frequencies as well. Not that some oscillators shifted too far away from expected frequencies... > So, from my point of view, we don't really need to argue the details of the > implementation much. Unless you really want to, I don't think that's the > main issue right now. What matters is that something is wrong, and it has > been wrong for a long time. I've not really paid much attention to it, but > I'm pretty sure it's been this bad for at least 15 years, if not more. As the VAX port made a hugh progress these days, I guess that timekeeping will be understood soon as well. :) My fast /96 is ready for testing, and any smaller system could be brought here quickly. MfG, JBG --
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