50g Random Turn ON

[DavidM]

(12-08-2016 05:32 PM)Joe Horn Wrote:  For example, sometimes TICKS goes BACKWARDS in the 50g, which of course is something that it should never do.

It is fair to say that the system clock moving backward is what started me down the path of thinking about these clock issues in the first place. I ran into that issue several years ago when working on MultiStopwatch, and was quite surprised how often it actually occurs. Whereas RPL code (user or sys) runs slow enough to only see it occasionally, it actually happens more often than many realize.

A simple Saturn ASM test on my older 50g shows "backward steps" happening about 100 times/sec with an average of about 35 ticks per event. My 49g+ sees about 75 of them averaging 26 ticks, and my newer 50g sees about 50 of them averaging 18 ticks (all per second). My guess is that these differences can be explained by slightly varying raw CPU speeds in the individual units.

More difficult to determine would be how often the clock jumps forward, if at all. But these fluctuations are one of the reasons I suspect that the Saturnator is constantly tweaking the system clock. I have long wondered if system clock jitter is behind some of these issues.