[cr0sh]

Waaay back in the day of PCs (late 80s, early 90s) the way to get "high res graphics" and "dual screens" was to hook up to your PC (which was usually an actual IBM machine) a CGA monitor for regular usage, and then add a Hercules card and monitor for the "second display".

Downside was that the Hercules - while being very high resolution for the day - was only monochrome, and amber. But it was a common solution for many CAD systems (with a price to match of course).

IIRC, it was also a setup that some later game programmers used (I may be wrong, but IIRC, Carmack used something like this?) - because they could run the debugger on the monochrome Hercules, while outputting the game on the color monitor (CGA/EGA/VGA). This was well after better solutions came around for CAD, so the Hercules setup was a relatively inexpensive upgrade.

[malkia]

I had Hercules for my first "IBM PC" computer, while everyone else either had CGA, EGA or even VGA! - It was the computer that my uncle left, before leaving for US - And yes, it was meant to run AutoCAD - lol

Being bored of not too many games working, I decided to take matter in my hands. Early on, I got into making various resident applications - and made one (used Turbo Pascal with inline assembly), where I would "convert" the 320x200 VGA buffer into Hercules bits. It was not taking care of what the palette was, but just happened to work by accident for some of the games (like Trolls). I also had to hack Trolls to first ignore the fact that I did not have VGA, then hack it instead of using 0xA0000 as VGA buffer (the standard address for an VGA adapter), but I would hack that location with my own buffer.

It kind of worked, real slow - I've got about - I dunno - maybe 5-10fps - lol.

Fun fact of trolls that I've found, but could not completely understood it back then (I was probably 9th or 10th grade, english is my secondary language) was this: https://www.mobygames.com/game/dos/trolls/trivia

"This game was written on a very slow schneider 10mhz 286 with lots of wait states. If for some reason on your very fast xxxx 25mh 486 this game seems to be fast or unplayable, do no blame us for it was a penny pinching boss who would not buy us reasonable pc's to work on. signed THE PROGRAMMERS OF FLAIR SOFTWARE"

So having hercules card made me - lol - did a bit of fun hacking :)

[rzzzt]

simcga was a similar utility, it used B800h for the CGA-compatible frame buffer (the card also had memory in that location as a secondary graphics page): https://en.wikipedia.org/wiki/Hercules_Graphics_Card#CGA_emu...

[malkia]

If I only knew back then, but it might've not been been available to me. Or it's possible that I've tried it, and might've even relied on it, as I played other games, but this one, along with few others were VGA only. Wow, now that i think of it... it was long time ago... Just trying to squeze that last bit of 640kb with QEMM... looool

[rzzzt]

Real mode x86 is certainly not the most accomodating environment for hardware emulation :)