On Monday, May 11, 2015 at 12:48 PM, Cory Smelosky wrote: > Okay, I should include all the information needed now. ;) > > With CPU IDLE set, with CPU set to TOPS-20 (running 4.1 running the TSU02 > monitor) SIMH continues to use 100% CPU. > > Does anyone have pre-existing patches to support idling or do I need to > provide a disk image to help identify it? > > Alternatively...some people here probably already know the idle instruction. > ;) > > PDP-10 simulator V4.0-0 Beta git commit id: 3b8c318b > > ( Interestingly, SET THROTTLE 20 causes >30% CPU usage, whilst 15 is 5% > which is just slightly above it being set to 12. This doesn't seem linear. > ;) )
This is a known problem. It arises from the fact that TOPS-20 has a clock tick size of 1ms which is likely smaller (or at best equal to) than the tick size of the host system. That said, I've got a project which, when complete "should" get reasonable idling behavior for this OS on almost any host system. For now, I think you are on a reasonable track using throttling. When you use throttling, simulated time (in the OS) won't track wall time at all though. Please follow up on this the pre-existing issue: https://github.com/simh/simh/issues/80 That will be where testing will be solicited. Thanks. - Mark _______________________________________________ Simh mailing list [email protected] http://mailman.trailing-edge.com/mailman/listinfo/simh
