Can someone elaborate on 386_slow & 486_slow??

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Can someone elaborate on 386_slow & 486_slow??

Postby Keatah » 2011-3-29 @ 00:39

Can someone elaborate on the 386_slow & 486_slow?? And also the 386_prefetch?? What exactly do these options do? Do they simulate a certain clock speed? Do they disable parts of the emulated chip?

Do they run slower than the regular cputype of, say, 386..? Are they more accurate and therefor run slower or what?

Exactly what is going on internally with dosbox when I have one of those options selected.
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Re: Can someone elaborate on 386_slow & 486_slow??

Postby mr_bigmouth_502 » 2011-3-29 @ 03:49

I think they just emulate different instruction sets.
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Re: Can someone elaborate on 386_slow & 486_slow??

Postby wd » 2011-3-29 @ 06:04

Exactly what is going on internally with dosbox when I have one of those options selected.

Check the sources if you need the "exactly" part.

They have different exception sets, may be slower due to paging differences.
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Re: Can someone elaborate on 386_slow & 486_slow??

Postby ripsaw8080 » 2011-3-29 @ 06:34

386_prefetch implements an instruction prefetch queue. A few games exploit queue behavior, usually as an anti-debugger measure.
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Re: Can someone elaborate on 386_slow & 486_slow??

Postby garrynichol » 2011-4-02 @ 04:48

My advice is to not try just changing one thing at a time after you've already tried that method.
Try intelligent combo changes. It worked for me but I wanted more SPEED. (AND NO I DON'T HAVE A LAB:)
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