Many of you know that you can use a “Jiffy” on a Commodore as a measure of time. Sorta.
The short short version is that we have a 3 byte clock that increments once every interrupt, so 1/60th of a second. It’s not considered reliable as a real time clock, but it IS useful for benchmarking.
According to “Compute’s Complete Guide to the C64” p. 156:
“TI equals PEEK(162) + 256PEEK(161) + 256256*PEEK(160); for TI$, the value of TI (in jiffies) is converted into hours, minutes, and seconds.
read more