leileilol wrote on 2022-04-26, 09:27:

Most of the recent official DOSbox releases can work on Win98 , just the P133 won't satisfy the CPU requirement.

Wow! so it's come to that point where it's better or easier to run dosbox on my p3 98 machine than to use 98's build in dos?

koleq wrote on 2022-04-18, 19:22:

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hmm I do have a 430FX chipset motherboard, I will see if this key combination works if I reboot to dos mode.

Is it the Intel oem Morrison with a riser card. If so the key combo should work.

kolderman wrote on 2022-04-18, 19:46:

If you just swap for a Pentium MMX you can use setmul to disable certain things and bring the speed down to 286 levels.

Doesn't setmul have exactly the same options when using a non-mmx Pentium 75-200.
Things like Disable pipeline, branch prediction etc. or do P1 MMX offer even more slowdown options v Pentium P54C.

Riikcakirds wrote on 2022-05-01, 14:19:

Doesn't setmul have exactly the same options when using a non-mmx Pentium 75-200.
Things like Disable pipeline, branch prediction etc. or do P1 MMX offer even more slowdown options v Pentium P54C.

Not every Pentium CPU has the "TR12" switches that can be used by SetMul. I have one Pentium 166 CPU where the only parameter that worked besides disabling the L1 cache was L1DX, which also disables the cache but programs will assume that the it is still enabled.

Gmlb256 wrote on 2022-05-01, 14:51:

Not every Pentium CPU has the "TR12" switches that can be used by SetMul. I have one Pentium 166 CPU where the only parameter that worked besides disabling the L1 cache was L1DX, which also disables the cache but programs will assume that the it is still enabled.

In my case, they worked on all of the Pentium MMX and non-MMX CPUs that I tested.
I never tested any earlier socket 4 / socket 5 Pentiums, so not sure about those. But when it comes to 133 / 166 / 200 / 233 socket 7 models, I was able to disable the branch prediction, instruction cache and data cache on all (and I've probably tested 50+ of these in the past few years).

bloodem wrote on 2022-05-01, 15:04:

In my case, they worked on all of the Pentium MMX and non-MMX CPUs that I tested.
I never tested any earlier socket 4 / socket 5 Pentiums, so not sure about those. But when it comes to 133 / 166 / 200 / 233 socket 7 models, I was able to disable the branch prediction, instruction cache and data cache on all (and I've probably tested 50+ of these in the past few years).

Lucky you. For me only the Pentium 166MMX and 233MMX were the ones that worked with all "TR12" parameters.

I don't have any more Pentium CPUs to test with though.

Gmlb256 wrote on 2022-05-01, 14:51:

Riikcakirds wrote on 2022-05-01, 14:19:

Doesn't setmul have exactly the same options when using a non-mmx Pentium 75-200.
Things like Disable pipeline, branch prediction etc. or do P1 MMX offer even more slowdown options v Pentium P54C.

Not every Pentium CPU has the "TR12" switches that can be used by SetMul. I have one Pentium 166 CPU where the only parameter that worked besides disabling the L1 cache was L1DX, which also disables the cache but programs will assume that the it is still enabled.

I pulled my Pentium 75 with a socket 5 430fx intel morrison motherboard out of storage.
I can confirm Setmul works with the TR12 switches on this P75.
To see how slow I could get this machine without disabling the Biggie, (L1 cahce):
I disabled L2 cache and the following TR12 options
BPD - Disable Branch Prediction.
VPD - Disable V Pipeline.
L1DX - Disable L1 cache exclusively.

Doing this it still only slows down to just slight under a 486DX4 speed. I used NSSI benchmarks for comparison. With all the above options on it hammers a 486DX4. Not really that useful as the gap between a dx4 and P75 is still too fast for these older games. I was hoping to get in the 486-25mhz range, with 386-33mzh covered by disabling L1.

Riikcakirds wrote on 2022-05-01, 19:19:

I pulled my Pentium 75 with a socket 5 430fx intel morrison motherboard out of storage. I can confirm Setmul works with the TR1 […]
Show full quote

I pulled my Pentium 75 with a socket 5 430fx intel morrison motherboard out of storage.
I can confirm Setmul works with the TR12 switches on this P75.
To see how slow I could get this machine without disabling the Biggie, (L1 cahce):
I disabled L2 cache and the following TR12 options
BPD - Disable Branch Prediction.
VPD - Disable V Pipeline.
L1DX - Disable L1 cache exclusively.

Doing this it still only slows down to just slight under a 486DX4 speed. I used NSSI benchmarks for comparison. With all the above options on it hammers a 486DX4. Not really that useful as the gap between a dx4 and P75 is still too fast for these older games. I was hoping to get in the 486-25mhz range, with 386-33mzh covered by disabling L1.

There are other "TR12" options that can partially disable the L1 cache such as CCD (code cache) and DCD (data cache) and it would require that the L1 cache isn't disabled either by using L1D or L1DX for these parameters to work.

To address the rest it would require combining SetMul with software based slowdown utilities, which badmojo showed an example using AT-SLOW on a 233 MHz Cyrix CPU to get around 486DX-33 range. YMMV however as they don't provide the best experience.

What is the full list of things I can try to disable, does the program have a help menu switch listing them?

Castle Wolfenstein is probably not possible on a Pentium system, I will never get slow enough to run that right?

Using setmul you can go down to a slow 386, so yes you can.

kolderman wrote on 2022-05-02, 23:24:

Using setmul you can go down to a slow 386, so yes you can.

OK, how?
I only know L1D, what other options should I run to slow the CPU down even further?

koleq wrote on 2022-05-04, 07:00:

kolderman wrote on 2022-05-02, 23:24:

Using setmul you can go down to a slow 386, so yes you can.

OK, how?
I only know L1D, what other options should I run to slow the CPU down even further?

Setmul tells you, but branch prediction and instruction caching are others. You need to be using a mmx cpu.

kolderman wrote on 2022-05-04, 07:43:

Setmul tells you, but branch prediction and instruction caching are others. You need to be using a mmx cpu.

I think it should be possible to go down to 386 speeds on a normal Pentium too.

Go to the BIOS and disable both L1 and L2 caches. If the L2 option (sometimes called External Cache) is not available in your BIOS, then you're out of luck.

Joseph_Joestar wrote on 2022-05-04, 07:59:

I think it should be possible to go down to 386 speeds on a normal Pentium too.

Go to the BIOS and disable both L1 and L2 caches. If the L2 option (sometimes called External Cache) is not available in your BIOS, then you're out of luck.

Yeah, my OEM HP motherboard does not let me disable any caches in the BIOS.

mothergoose729 wrote on 2022-04-12, 22:00:

In the early 90's most games were not speed sensitive, but those that were generally expected 386 class performance. A Pentium 1 is roughly similar to a 386DX33 with L1 cache disable.

actually there's more speed sensitive DOS games than people think, even past the early 90s and including major releases. an interesting case is magic carpet, which came out in late 1994. say you had a top-end machine right from that time, a pentium 90 or 100, the game would run way too fast in VGA mode but SVGA would be a slideshow. this is exactly mentioned in this discussion from back in the day: https://groups.google.com/g/comp.sys.ibm.pc.g … /c/SU0h8PA38M4/

so if your machine didn't have the correct settings for disabling L1 but leaving L2 enabled in the BIOS, which OEM systems generally didn't, your only option was to play in SVGA with shrinking the screen size a lot+disabling detail; hardly a good experience. i think other bullfrog releases like syndicate wars are in that same boat.

then there's descent, which feels exactly the right speed to me in VGA on a 430NX P90, but put it on a faster pentium and you might be stuck fiddling with some of those intermediate modes with distorted HUD text and missing cockpit graphics.

so you don't even need to go pre-pentium era at all to find problematic games.

auron wrote on 2022-05-08, 16:08:

then there's descent, which feels exactly the right speed to me in VGA on a 430NX P90, but put it on a faster pentium and you might be stuck fiddling with some of those intermediate modes with distorted HUD text and missing cockpit graphics.

so you don't even need to go pre-pentium era at all to find problematic games.

Indeed, the first two Descent games aren't easy getting it running at right speed in 320x200 with later CPUs.

For the first game a sort of workaround could be used with command line switches for 320x400, 640x400 and 640x480, however the cockpit view and the status bar mode will be lost. At least the second game has a proper high resolution option without these compromises.

auron wrote on 2022-05-08, 16:08:

actually there's more speed sensitive DOS games than people think, even past the early 90s and including major releases. an inte […]
Show full quote

mothergoose729 wrote on 2022-04-12, 22:00:

In the early 90's most games were not speed sensitive, but those that were generally expected 386 class performance. A Pentium 1 is roughly similar to a 386DX33 with L1 cache disable.

actually there's more speed sensitive DOS games than people think, even past the early 90s and including major releases. an interesting case is magic carpet, which came out in late 1994. say you had a top-end machine right from that time, a pentium 90 or 100, the game would run way too fast in VGA mode but SVGA would be a slideshow. this is exactly mentioned in this discussion from back in the day: https://groups.google.com/g/comp.sys.ibm.pc.g … /c/SU0h8PA38M4/

so if your machine didn't have the correct settings for disabling L1 but leaving L2 enabled in the BIOS, which OEM systems generally didn't, your only option was to play in SVGA with shrinking the screen size a lot+disabling detail; hardly a good experience. i think other bullfrog releases like syndicate wars are in that same boat.

then there's descent, which feels exactly the right speed to me in VGA on a 430NX P90, but put it on a faster pentium and you might be stuck fiddling with some of those intermediate modes with distorted HUD text and missing cockpit graphics.

so you don't even need to go pre-pentium era at all to find problematic games.

There really aren't that many speed sensitive games and the speed sensitivity problem is way over blown, IMO. Magic Carpet is one example sure, and there are a couple more like Terminator Future Shock and Alien Trilogy that run best on a slow Pentium. After 1992 or so the overwhelming majority of games people actually want to play run fine, and many of that don't can also be patched. Also, its not like these games can't be played on a faster pentium or K6-2 either, and there are tools like mo slow that get the job done, and god for bid dosbox.

BTW, none of those three games are actually any good either, IMO.

If your nostalgia zone is pre 1992 then yeah it can be trickier but even then most of your classics don't need special treatment. The good news is that most games from the 1990-1992 era that are speed sensitive run just fine on 386 class speed which most DOS machines can do with a little tweaking. So again, speed sensitivity as a whole feels kind of over blown.

auron wrote on 2022-05-08, 16:08:

actually there's more speed sensitive DOS games than people think, even past the early 90s and including major releases. an inte […]
Show full quote

mothergoose729 wrote on 2022-04-12, 22:00:

In the early 90's most games were not speed sensitive, but those that were generally expected 386 class performance. A Pentium 1 is roughly similar to a 386DX33 with L1 cache disable.

actually there's more speed sensitive DOS games than people think, even past the early 90s and including major releases. an interesting case is magic carpet, which came out in late 1994. say you had a top-end machine right from that time, a pentium 90 or 100, the game would run way too fast in VGA mode but SVGA would be a slideshow. this is exactly mentioned in this discussion from back in the day: https://groups.google.com/g/comp.sys.ibm.pc.g … /c/SU0h8PA38M4/

so if your machine didn't have the correct settings for disabling L1 but leaving L2 enabled in the BIOS, which OEM systems generally didn't, your only option was to play in SVGA with shrinking the screen size a lot+disabling detail; hardly a good experience. i think other bullfrog releases like syndicate wars are in that same boat.

then there's descent, which feels exactly the right speed to me in VGA on a 430NX P90, but put it on a faster pentium and you might be stuck fiddling with some of those intermediate modes with distorted HUD text and missing cockpit graphics.

so you don't even need to go pre-pentium era at all to find problematic games.

Hi octane (dos), Redline racer (windows) also.
Even today, some games are speed sensitive like skyrim.

AvalonH wrote on 2022-04-18, 22:51:

koleq wrote on 2022-04-18, 19:22:

Riikcakirds wrote on 2022-04-16, 22:46:

I remember in the early Pentium era this was on Intel's own branded motherboards up to the 430fx chipset. Intel Zappa, Endeavor, Morrison etc.
Seemed pretty cool as the motherboard manual said it emulated a 23MHz AT pressing ctrl+alt+ minus key. It would only work in real mode though, didn't work in protected mode or V86 mode, so no emm386.

hmm I do have a 430FX chipset motherboard, I will see if this key combination works if I reboot to dos mode.

Check if it is one of the 'Intel Advanced' 430fx motherboards mentioned above, (look at the PBA# and AA# on the board). You could also flash a MR-Bios update on those boards which added more features, I did it with an Intel Advanced Endeavor board in 1996.
I don't know if someone here remembers whether Mr-Bios supported the software turbo switch (ctrl+alt+plus/minus) that the original Intel bios featured.

Yes, ctrl + alt + plus/minus slowdown hotkey combination also works on MR.BIOS 3.30 for Intel Advanced/EV (Endeavor rev.1).

It goes down to about 386DX-33 speeds but only in Real mode.