RELOGIO (2004) http://zx81.eu5.org/toddysofte.html
I have adapted it to English. The source code shows the machine language.
- RELOGIO English P file and ASM file
- (2.55 KiB) Downloaded 199 times
Just tried this on one zeddy and it lost 10 seconds in the first three minutes so a nice novelty but not very practical.
Even if (maybe) "off-topic".
So the ZX81 user could POKE somewhere a value to be added or subtracted to the actual FRAMES counter after a given number of ticks. Determining the right setting for such values could be done with a test application looping long enough, asking the user for his own time measurements and computing the optimal values for the 2 parameters (hoping the thermal drift impact and the components age effect are low enough).
You might integrate the graphics too, borrowing my clock.c example in the z88dk tree.
The default look-and-feel is naked to permit the low resolution devices to act good, but it is possibe to pass a #define and get a graceful HR quadrant.
Addendum: English version
https://www.amazon.de/WORTUHR-Tisch-Wor ... word+clock