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.

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

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.

I was never satisfied with a Pentium for DOS era titles with the exception of later software rendered 3D titles. Old games (< 1991) were often too wonky feeling, something that bios tweaks and tools like Moslo never fully resolved for me.

I brute forced the situation by configuring a 386 33DX, 486 50DX and an AMD 586 system for all of my needs. I definitely think the P1 can be corralled to work, but there are going to be compromises.

bstar wrote on 2022-04-20, 01:37:

I was never satisfied with a Pentium for DOS era titles with the exception of later software rendered 3D titles. Old games (< 1991) were often too wonky feeling, something that bios tweaks and tools like Moslo never fully resolved for me.

I brute forced the situation by configuring a 386 33DX, 486 50DX and an AMD 586 system for all of my needs. I definitely think the P1 can be corralled to work, but there are going to be compromises.

Is it really that bad? Should be possible change the multiplier to run DOS games.. I have to do some experiments on my pentium 1 non MMX socket 5 system. Maybe I need to replace the CPU with a Cyrix..

Joakim wrote on 2022-04-20, 05:14:

Is it really that bad? Should be possible change the multiplier to run DOS games.. I have to do some experiments on my pentium 1 non MMX socket 5 system. Maybe I need to replace the CPU with a Cyrix..

Changing the multiplier on Pentium CPUs requires opening the computer case to adjust the jumpers (or DIP switches) provided that it is unlocked downward.

If the computer case has a Turbo button and the motherboard uses jumpers to configure the CPU multiplier, there is a hack where the Turbo button cable could be strapped into the jumpers. To take effect it wold require turning off/on or restarting the computer.

In addition to this certain Gigabyte Socket 7 motherboards comes with a proper Turbo header for 50 MHz FSB, where at first sight it doesn't seem that useful but it will become more noticeable where both the CPU and motherboard caches are disabled.

I've tried playing MechWarrior 1 (1989) and it runs too fast on my Pentium.
the game came included with a program called atslow, but I couldn't figure out how to use it, starting this program and setting any slowdown rate
always froze the whole computer.

So, I've decided I will only play games that will natively work on the machine, in the worst case I can play older/newer games on my modern PC using emulation.

@koleq:
AtSlow froze your computer? Are you using plain MS-DOS or some version of Windows too on your Pentium?

koleq wrote on 2022-04-21, 05:05:

the game came included with a program called atslow, but I couldn't figure out how to use it, starting this program and setting any slowdown rate
always froze the whole computer.

That slowdown program relies on the RTC's interrupt and works in "MS-DOS mode" or pure DOS. It comes with a DOC file explaining how it works.

Managed to get the game running just by disabling L1 cache it runs manageably now,
but I got interested in early 80s games too, is there any way to run Castle Wolfenstein on hardware, or is there a version of DOS-BOX that works on Windows 98 SE?

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

Oh, that makes sense, but I am real worried trying to figure out those programs that are supposed to slow you PC down, because I don't think they work very well.

I never managed to use them.

Forget running the early 80s games without relying on software based slowdown utilities (which doesn't provide the smootest experience) or emulation on that Pentium computer because you will never achieve the adequate speed (almost impossible to reach 8088 CPU speeds with what currently you can do) and requires real CGA card for tweaked modes and composite output.

Joakim wrote on 2022-04-20, 05:14:

bstar wrote on 2022-04-20, 01:37:

I was never satisfied with a Pentium for DOS era titles with the exception of later software rendered 3D titles. Old games (< 1991) were often too wonky feeling, something that bios tweaks and tools like Moslo never fully resolved for me.

I brute forced the situation by configuring a 386 33DX, 486 50DX and an AMD 586 system for all of my needs. I definitely think the P1 can be corralled to work, but there are going to be compromises.

Is it really that bad? Should be possible change the multiplier to run DOS games.. I have to do some experiments on my pentium 1 non MMX socket 5 system. Maybe I need to replace the CPU with a Cyrix..

For me it has been the case. I also have a few games that just segfault right away on Pentiums. Changing the multiplier is not practical and I don't believe any Pentiums ever supported Turbo functionality, so you'll have to rely on something like MoSlo. Also, things like cache and other CPU features affect performance that are not tied to frequency.

Test Drive II and III are examples of games that are hard to get the right feel if you are on a pentium. It can be achieved in DosBox (DOSBox is a good way to test how titles will perform on various hardware), but the Pentium hardware is just too fast for these games, even with slowdown tools. TD III plays like a dream on a 386 16Mhz sx, and that's the experience I'm ultimately looking for. I'm not advocating that you need the older hardware, but definitely snag it if you have the opportunity and it's a good deal. There's value there if you like < 1991 era games.

bstar wrote on 2022-04-28, 16:58:

For me it has been the case. I also have a few games that just segfault right away on Pentiums. Changing the multiplier is not practical and I don't believe any Pentiums ever supported Turbo functionality, so you'll have to rely on something like MoSlo. Also, things like cache and other CPU features affect performance that are not tied to frequency.

Seems that you didn't read my post which mentions some information about using the Turbo button on Socket 7 motherboards. 😐

Still, I'm currently using a K6-2+ CPU for flexiblity reasons as it allowed me to switch the CPU multiplier on the fly.

Gmlb256 wrote on 2022-04-28, 18:21:

bstar wrote on 2022-04-28, 16:58:

For me it has been the case. I also have a few games that just segfault right away on Pentiums. Changing the multiplier is not practical and I don't believe any Pentiums ever supported Turbo functionality, so you'll have to rely on something like MoSlo. Also, things like cache and other CPU features affect performance that are not tied to frequency.

Seems that you didn't read my post which mentions some information about using the Turbo button on Socket 7 motherboards. 😐

Still, I'm currently using a K6-2+ CPU for flexiblity reasons as it allowed me to switch the CPU multiplier on the fly.

That's a good hack for certain games, but I agree with bstar that Test Drive III will run too fast on a Pentium. The sweet spot for this game is indeed a 386sx16 and in my experience even a Pentium set to 1.5x50Mhz and the cache off won't feel right for it. This is one of these notoriously tricky games that benefit from being played on the "right" system

koleq wrote on 2022-04-21, 05:05:

the game came included with a program called atslow...

AT-slow is awesome, and when combined with SETMUL to disable L1 cache I've found that you can get a nice smooth slow-down, unlike other software options which I've found to be inconsistent.

EDIT:

For example this slows my 233MHz Cyrix down to 33MHz 486 levels:

1C:\UTILS\SETMUL\SETMUL >nul L1D
2C:\UTILS\AT-SLOW\AT-SLOW >nul /T133

Gmlb256 wrote on 2022-04-28, 18:21:

Seems that you didn't read my post which mentions some information about using the Turbo button on Socket 7 motherboards. 😐

Still, I'm currently using a K6-2+ CPU for flexiblity reasons as it allowed me to switch the CPU multiplier on the fly.

Sorry, you are correct, I glossed over that somehow. I've actually not used SetMul yet... I have an original K6 200 that I was planning to mess with over the weekend, so perfect timing to try this all out.

bstar wrote on 2022-04-29, 13:46:

I've actually not used SetMul yet... I have an original K6 200 that I was planning to mess with over the weekend, so perfect timing to try this all out.

Unfortunately, adjusting the CPU multiplier with SetMul won't work with non-K6plus CPUs. 🙁

At least that utility has some additional slowdown options for supported Pentium CPUs with the "TR12" swtiches.

Gmlb256 wrote on 2022-04-29, 14:01:

bstar wrote on 2022-04-29, 13:46:

I've actually not used SetMul yet... I have an original K6 200 that I was planning to mess with over the weekend, so perfect timing to try this all out.

Unfortunately, adjusting the CPU multiplier with SetMul won't work with non-K6plus CPUs. 🙁

At least that utility has some additional slowdown options for supported Pentium CPUs with the "TR12" swtiches.

Thanks for the headsup, that's unfortunate.