Reading the documentation for Applesoft BASIC, there is no timer, no sleep and no internal clock.
From a fairly reasonable sounding source:
The Apple ][ and ][+ don't have any built-in hardware timers, so you generally have to do them in software. This typically means doing carefully timed delay loops which will execute in a known amount of time. This is tricky if the computer might have an accelerator, unless you use a well defined timing routine which behaves predictably in the presence of an accelerator. The Apple IIe and later models have a hardware input which can be used to detect screen refresh, but you have to poll it fast enough to ensure you don't miss the signal. It isn't useful for long term timing if you want to do any disk I/O. You also need to know the screen refresh rate (50 or 60 Hz, depending on the model and settings) if you want to use it for general purpose timing. If you have a real time clock installed, it may provide some useful timing features. From: vcf-midatlantic <vcf-midatlantic-bounces@lists.vintagecomputerfederation.org> on behalf of Evan Koblentz via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> Sent: Wednesday, May 24, 2017 1:02 AM To: Vcf Cc: Evan Koblentz Subject: [vcf-midatlantic] Computing time in BASIC Suppose I want an Applesoft (Microsoft) BASIC program to do something for a certain amount of time as measured in seconds or minutes. FOR-NEXT loops don't align to any real increment -- they just count based on how fast the processor can go, right? If so, then how do you make something happen for a time amount? ------------------------- Evan Koblentz, director Vintage Computer Federation A 501(c)3 educational non-profit Evan@vcfed.org (646) 546-9999 www.vcfed.org facebook.com/vcfederation twitter.com/vcfederation