=20
> What's the significance of 100Hz with 1 second counting? :)

100Hz (or a multiple of) is the frequency of timer IRQs, not an
actual waveform frequency in the hardware as such

> What is the rb part? I can't find any reference to it in the MPASM
> help file. :)
>=20
> ticks  rb                  ;count IRQs (200 per sec)

It simply reserves a byte for counting ticks. Note that it's old (very
old) code, before I started using MPLAB, which uses 'res'. I'd have
to go back to WFW to compile most of those programs again ;-)) !!

The point is that the logic (or the resulting code) hasn't changed

All that's needed is a source of interrupts and a number of counters/
digits to increment

Many ways to do it, but for example something like -

Set Timer1 to produce 100 IRQs/sec
Test Start button or event
Increment 100ths counter
Test buttons (Stop, Pause, Reset etc)
Increment seconds counter when 100ths =3D 100
And/or update display
Loop to Increment 100ths counter

It will be a relatively short program

Joe
--=20
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