10-30-2011, 06:09 PM
(This post was last modified: 01-11-2021, 11:05 AM by boriel.
Edit Reason: Fix URL
)
You should have a look at Chapter 18 of the Sinclair ZX Spectrum manual.
http://www.worldofspectrum.org/ZXBasicMa...hap18.html
http://www.worldofspectrum.org/ZXBasicMa...hap18.html