Remarks:
This is a program which draws an analogue clock on the screen in Hi-res graphics using the HRG drivers. It automatically adjusts for a UK Sinclair ZX81 running at 50Hz, or an American Timex-Sinclair 1000 running at 60Hz. Hi-Resolution Graphics drivers developed in software and a graphics capable RAM pack by Matthias Swatosch - http://www.swatosch.de/zx81/