Posted By
TLC
on 2023-06-06
08:59:20
|  Re: Emulation video option you never knew you wanted until now!
@Charles sure. I'll have to take the machine apart first. (--> optionally 2 machines, because there have been two / slightly different PCB revisions.) I'll open a separate topic for that.
Foot note: such "patterning" artifacts can also appear when using composite (or even RF) links, to some extent. The underlying story is, that "RF" is composite video modulated to a carrier (with some band shaping / limiting applied first... plus sound, but that's not related here). "Composite", in turn, is luma + chroma added together, with some luma band limiting applied first. To display, RF has to be demodulated to get composite, and composite has to be separated to get luma/chroma back. Now... This step (composite to luma / chroma separation) is a non-exact task (by nature), and it can, and usually does, result in artifacts. Particular outlook and artifacts depend on filter type, implementation, parameter tuning, whatever... the outcome varies from TV to TV, monitor to monitor, aging, settings, etc. etc.
@MIK: now that you said, indeed I seem to remember that scrolling used to look... well... particularly smooth, "back then". Subjectively. Almost like, well, moving content would just "flow" on the screen. Might be, possibly, that we're talking about the same phenomenon?  I remember this from the time when we were still using "classic" TV sets in the old days. (By classic I mean typical early to mid '80s TV sets, wooden cabinet, early inline CRT's, fully analog circuitry, RF input.) More recent displays might also show this, only tests could really tell. "I" don't really remember this effect to appear that pronounced on newer displays, but OTOH, I haven't used that many different displays either. (I mostly used a C= 1801 in the late '90s, then switched to contemporary, late '90s / early 2000's household TV sets, and then the 1084S for the last maybe 2-3 years. None of them really showed this smooth / flowing character as I remember.)
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