[GTALUG] mysterious restarts

Lennart Sorensen lsorense at csclub.uwaterloo.ca
Thu Jun 16 15:54:58 EDT 2016


On Thu, Jun 16, 2016 at 12:53:15PM -0400, Peter Hiscocks via talk wrote:
> The Commodore PET and 64 had a 60Hz real-time-interrupt that did a bunch
> of housekeeping. You could patch your own routines into it, which was
> really handy.

Wow so the original C64 actually passed 9V AC on a pair of power supply
pins for the clock, while later models had an onboard crystal.  I didn't
know that.  That would make doing a replacement power supply a bit tricky.

> After a particularly nasty bug, that's where I learned about the
> importance of semaphores in controlling access to shared resources ;)

Good lesseon to learn early.

-- 
Len Sorensen


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