Hello everyone,

It just happened that I've thought of an old topic about MCGA hardware..
MCGA monitor at 15 KHz?

That's when I started to wonder "How would MCGA games have had looked on an actual 15 KHz monitor ?"
So I decided to do a little bit of experimentation here..

A few words..
MCGA is interesting insofar that it is very simple and uses linear addressing of its 64KB "large" (tiny, size of an x86 segment) frame buffer.
It's essentially the equivalent to a simplified TTL version of a VGA card, minus all the intelligence.
Yet, it still can do mode 13h with its standard settings. Which makes it some proto-VGA from another dimension.
Its monochrome mode (mode 11h) also has the VGA-typical 640x480 60Hz resolution we knew from MS Windows 3.x.

Setup.
I'm using a 286 PC with Trident 9000 ISA VGA, an 19" LCD (5:4), a VGA converter and an European SCART TV (CRT).
The VGA converter is active, it's a frame buffer device. It's being configured for NTSC mode, to give 640x480 output.
If I had a real NTSC monitor, Composite or S-Video would work as well.

Oh, and I'm a bit cheating. 😉 The LCD monitor isn't an ideal reference.
It's more like a "worst case scenario", to highlight the differences between a CRT.
Aspect ratio also is such a thing.. It's not accurate. The CRT TV comes close, but isn't perfect, either.

That's because I'm using a PAL TV/Monitor and no native VGA-RGB cable, but an external converter box.
If I had an homemade cable at hand, I could re-program the VGA card to use TV compatible timings (15 KHz vs 31 KHz etc).
Such tools are available in places like this: https://www.geocities.ws/podernixie/htpc/cables-en.html

Games.
I'm trying out those using the 320x200 lo-fi resolution with 256 colours.
These games are special insofar that they rely on dithering and colour-gradients to trick the human eye into seeing smooth graphics.
Such games are (were) mainly popular in the western world (US/Canada, Europe etc), while Japan went the hi-res, low colour way (see PC98).
That's because their sophisticated writing needed higher resolution, anyway.
Same goes for western desktop games (Win 2&3, Atari ST/GEM, Macintosh) run in high resolution mode,
and interactive fiction with graphics/simulations on PC which use standard VGA (mode 12h) and Super VGA (800x600 16c).

Motivation.
I'm trying to find out how low-fidelity CRTs perform on those low-res PC games.
The widely accepted opinion is that old games generally need hi-quality RGB monitors, with fine screen masks and scan lines (the dead black ones).
As if they were games as found on the NES/Famicom, Amiga or Arcades. But VGA was different, it did use scan-doubling for once (320x200 became 320x400).
Now, how does MCGA fit into the picture? That proto-VGA? It could do 31 KHz (320x400) and 15 KHz (320x200), depending on the monitor attached.
(With limitations. In the 15 KHz mode, in "TV" mode, the monochrome mode went away understandable. AFAIK.)

So that's why in this thread/topic, I'll essentially do the opposite. I'll see how a big dot pitch make them look.
It's said that quality VGA monitors (CRT) had an average 0.24 to 0.28 dot pitch, with 0.4 and 0.5 being very bad.
But those sources often show a boring, beige VGA monitor of 15 to 17" size, with an on-screen display and energy-saving features,
thus putting them into the past-1995 time frame, the Win 95 days. But were they same to 13" and 14" MCGA&VGA monitors from the 1987 onwards?

And how does porting affected these games? Some lo-fi games were lo-fi, because they originated on another platform.
So dithering patterns and gradients weren't made with a PC's scan-doubling graphics hardware in mind.
They'd rather been designed for video monitors and consumer TVs. Or so I think.

On the other hand, the YT video about the "worst VGA monitor" gave me hope and confidence.
https://www.youtube.com/watch?v=m79HxULt3O8

The grainy graphics it displays are similar to what I was used to see on my 1987-1990 era IBM PS/2 monitor back in the 90s.
Interestingly, these 320x200 PC games shown do look very natural at that VGM-225's 0.52mm dot pitch! ^^
So they weren't always being ugly, hi. It's just seem to happen that the designers/pixel-artists of back then worked with a specific setup in which they looked nicely.
Windows 3.1 in VGA looks somewhat fuzzy, though. Much worse than I remember it on my IBM PS/2 monitor. 😟
So I guess we can't have both.. It's either MCGA or VGA, in terms of fidelity. 🤷

Links.
The secret story of MCGA
https://www.swiat-owocow.pl/lang/en/1285.html

IBM Multi-Color Graphics Array
https://en.wikipedia.org/wiki/Multi-Color_Graphics_Array

The IBM Model 30 and MCGA proto-VGA
https://www.youtube.com/watch?v=61UbTmlTWSU

Any thoughts welcome. 😁

Best wishes,
Jo22

PS: I'll start with a beloved classic, The Secret of Donkey Island.