ViTi95 wrote on 2025-03-19, 07:41:

Basically they use the CPU for certain operations, which slow everything down. There isn't much more information about how it really works. Also seems not everything is 100% implemented.

That explains why Doom performs relatively worse than Quake, which I think uses the FPU more than the ALU.

For older games it's not a big issue that it uses the CPU, since it's so much faster than an early 1990s CPU.

The problem is that many games exhibit that sort of sporadic flashes, like The Lost Vikings, Gods, Lemmings, Cannon Fodder, Wacky Wheels.

Lotus 3 for instance doesn't, but it runs in slow motion, as if it were started with Moslow. UVCONFIG fixes this and then it works just fine!

So, my impression is that a hacker could create a different TSR to fix that problematic VGA mode. Hopefully, one will.

Here's the full confidential Cyrix document for the VGA hackers out there.

Are there other TSRs such as UVCONFIG worth trying?

Lotus 3 is probably slow because vsync. It requires the screen to update at 70hz, on most laptops the screen updates at 60hz (85% real speed).

ViTi95 wrote on 2025-03-19, 10:18:

Lotus 3 is probably slow because vsync. It requires the screen to update at 70hz, on most laptops the screen updates at 60hz (85% real speed).

It's not that it works at 85% speed, it's crawling speed. Very very, very slow.