It might be worth looking at call -856, which appears to allow for arbitrary time delay on the Apple II:
From https://mirrors.apple2.org.za/ground.icaen.uiowa.edu/Collections/1WSW/MEGA.P...
$FCA8....64680....CALL -856......WAITs; executes time delay; set delay value (dly) to the accumulator (address 69 or $45) before CALLing; the delay time (in seconds) can be found using this equation: delay=(0.5*(5*(dly*dly)+27*dly+26))/10000 Devin On Wed, May 24, 2017 at 11:28 AM, Glenn Roberts via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
It's a good question. With only Google as my guide (I'm admittedly no Apple expert!) it appears that Apple introduced a display refresh signal with the IIc model (50 or 60 Hz, depending on settings) and a true real time clock beginning with the IIgs. Since the Laser is apparently a IIc clone, perhaps it's using the display clock?
-Glenn
Sent from my iPhone
On May 24, 2017, at 10:10 AM, Evan Koblentz via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
Thanks everyone. Interesting stuff.
Here's something I do not understand. Lego's modified version of Logo has a command, COUNTER, which they say increments in tenths of a second. One of their sample programs runs the counter to 600 to give you a minute of something happening (a motor spinning). I didn't time it against a real clock, but, how could this work? The same Logo environment disk runs identically in anything from a ][+ through a GS. (My demo uses a Laser 128 as you'll recall.)
-- Devin J. Heitmueller http://www.devinheitmueller.com