One of the tricks you can do on the C64 involves manipulating the video chip into reading the graphics data at an offset from where it’s usually located. This allows you to scroll the display horizontally, and the trick is called VSP for Variable Screen Position. However, some machines crash when you attempt this, and the reason for that has always been a mystery. Not anymore.
Always under-clock, this particular one 90/100 from specification. Metalized RF-shield|Heat-dissipator.[Also CPU and GPU].
V same, squarer waves, preciser timings
I think the title is wrong, this is not a bug that has just been discovered.
This is a bug that has been known for decades, it was the cause of the bug that has been discovered. And while work-arounds had already been known, now a programmer knows what is needed to avoid the bug since there is more than one way to handle it.
Edited 2016-06-07 03:49 UTC