First post, by Revolter
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Help me disable some advanced features of a Pentium 3 CPU, please 😀
I've owned these two computers during my youth: a Pentium 133 - which was my first love and essentially what got me into IT, and a Coppermine-based Celeron 800 - which can run some 3D-heavy games like Deus Ex and Morrowind, and which I also have fond memories of. I've re-made both as dedicated "retro-PCs" over the last year for the purpose of playing my fav old games exactly the way I remember them, but, since I only have room for one PC secondary to the regular modern one, I'm now trying to unite these two machines into a single one that can switch back and forth between them in terms of performance - using the s370 platform as a base.
So far this venture was mostly a success: I went for a Pentium III 600EB instead of a C800 (they are roughly the same, but the PIII has more benefits), and with chipset throttling via Throttle dividing the performance in half (50% skipped CPU cycles) on the 66 Mhz FSB (600@133 > 300@66) the resulting 150 Mhz performance is VERY MUCH like the P133 I remember and have close by for comparison. For instance, there's just a 2 FPS difference in Quake, which I consider to be negligible 😀
However, there are other games that differ too much performance- and feel- wise: Tiberian Sun, Worms World Party, Heist, Dune 2000, Klingon Honor Guard. They are a tad faster than on the genuine P133 computer. It was much worse before I discovered the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw\ "DisableMMX" registry switch, but it's still not a perfect match.
I wouldn't be bothered that much about the exact performance, if it wasn't easily achievable by disabling the DirectDraw acceleration! With it disabled, these games start to perform EXACTLY as on the real Pentium 133 (WITH the acceleration enabled), which is amazing to me, but there is a slight problem that comes with this: only a handful of games tolerate being run with emulated framebuffer. Games like Red Alert and Need for Speed III do not even start unless the acceleration is turned back on.
I've tried using the MTRRLFBE util with the "Write Protected" switch: it does the trick somewhat and the performance is getting there, especially for 3D-games, but it gets intolerably choppy during any kind of 2D-scrolling (especially in Dune 2000 and Heist), while with the true P1 or the software DDraw it is smooth, just not fast. I've also tried all other DirectDraw and MTRRLFBE switches to no good effect.
Guys, are there any other tricks that could make the DirectDraw still provide the resources necessary for the games seeking hardware acceleration to be able to run, but behave like software emulation in terms of speed?
Thanks in advance!
