First post, by Laaca
In the past I had a czechoslovakian computer PP-O6 with soviet clone of the i8086 CPU and with modified CGA graphic card.
The CGA modifications meant the hardware czech/slovak font (in 895 coding) and absence of "snowing" while writting to videomemory during vertical retrace.
And it also did interresting effect when I ran a game using EGA or VGA mode.
The mode was not set, of course, but on monitor occured an artefact similar to "snowing" or rather "snow storm". It differed whether EGA or VGA mode was tried to set.
My question is whether such artefact occures also on original CGA cards and whether the "snow storm effect" can be somehow controled by programmer using direct port accessed to CGA card.