Maybe it's simply bad VGA compatibility in the Ati. Keen uses some sophisticated EGA and VGA features.

root42 wrote on 2020-02-27, 09:35:

Maybe it's simply bad VGA compatibility in the Ati. Keen uses some sophisticated EGA and VGA features.

Yep, see https://gona.mactar.hu/DOS_TESTS/.

Try a different card, or use DOSBox, Keen 4-6 under it is indistinguishable from real hardware.

ynari wrote on 2020-02-27, 09:45:

root42 wrote on 2020-02-27, 09:35:

Maybe it's simply bad VGA compatibility in the Ati. Keen uses some sophisticated EGA and VGA features.

Yep, see https://gona.mactar.hu/DOS_TESTS/.

Try a different card, or use DOSBox, Keen 4-6 under it is indistinguishable from real hardware.

Wow. That is one extensive matrix! Nice link!

There is a patch to fix ATI compatibility problems in Keen 4, 5, 6:

Re: Keen 4-5-6 choppy scrolling on EGA card

Here's a more up-to-date version of my Keen 4-6 fixes. https://pckf.com/viewtopic.php?f=4&t=6192

I think you'll get better results with these updated patches. But the new code does introduce a slight delay after updating the screen, which may be noticeable on rather slow systems (286 and below). Just use whatever seems to work best on your system.

ynari wrote on 2020-02-27, 09:45:

use DOSBox, Keen 4-6 under it is indistinguishable from real hardware.

losing that border is pretty distinguishable

If you want that border, give Omnispeak a try.

leileilol wrote on 2020-02-28, 03:11:

ynari wrote on 2020-02-27, 09:45:

use DOSBox, Keen 4-6 under it is indistinguishable from real hardware.

losing that border is pretty distinguishable

Oddly, I don't remember a cyan border, so either I was being blind when doing a comparison (I did a Dosbox vs Real DOS Keen 6 A/B comparison), or it doesn't appear on my system. I'll have a look again tonight..

That border is the "overscan" area. As far as I can tell, it's only visible on real hardware when connecting the monitor via a VGA cable, not DVI or HDMI or whatever. It's also possible that more modern CRT and/or LCD monitors adjust the position of the display so that the overscan area is not visible. But it's definitely visible on old CRTs.

it's also visible through the OSSC