A bunch of big DOS games were released in 1997 in fact. Fallout, Grand Theft Auto, Blood, Carmageddon, Dungeon Keeper, etc.

What's best depends on what you want it to do.

dnewhous wrote:

What about DR-DOS, which is no longer available? Would it have worked better on a 80486 or on a Pentium Pro?

The legal status of DR-DOS is a bit fuzzy. (You can also easily find versions of OpenDOS, which is a derivative.)

I can't imagine what sort of metric you could use to establish whether one processor is "better" than another when it comes to running any particular version of DOS. in the end, DOS is too simple for that to enter into consideration.

Socket 8 hardware is uncommon and sometimes expensive and there is very little reason to pursue it when cheaper alternatives that work just as well are available.

DR-Dos, Novell-Dos, MS-Dos and IBM-Dos were the choices back in the early to mid 90's.
Two of them is actually the same. I just can't remember if it was Digital that bought Novell-Dos.
Or the other way around. Uhh.... There is also Caldera Dos if you can source a copy.

brostenen wrote:

Two of them is actually the same. I just can't remember if it was Digital that bought Novell-Dos.
Or the other way around. Uhh.... There is also Caldera Dos if you can source a copy.

DR-DOS was bought by Novell and the sold to Caldera, pretty much. It's all ancient history.
https://en.wikipedia.org/wiki/DR-DOS

Jorpho wrote:

Socket 8 hardware is uncommon and sometimes expensive and there is very little reason to pursue it when cheaper alternatives that work just as well are available.

Socket 8 stuff, as well as MCA, EISA and other "special" or rare stuff, are for those who eighter have used it personally back in the day's when it was new stuff. Or for people/museums that are collecting for historic reasons, in order for this hardware, not to get completely lost for good.

Jorpho wrote:

brostenen wrote:

Two of them is actually the same. I just can't remember if it was Digital that bought Novell-Dos.
Or the other way around. Uhh.... There is also Caldera Dos if you can source a copy.

DR-DOS was bought by Novell and the sold to Caldera, pretty much. It's all ancient history.
https://en.wikipedia.org/wiki/DR-DOS

Ahhh.... I clearly remember when Novell bought DR Dos. It was what everyone dealing with computers, talked about for a week or two.
People were really attached to DR Dos. And thought that it was sad when it happened.

Jorpho wrote:

The legal status of DR-DOS is a bit fuzzy. (You can also easily find versions of OpenDOS, which is a derivative.) […]
Show full quote

dnewhous wrote:

What about DR-DOS, which is no longer available? Would it have worked better on a 80486 or on a Pentium Pro?

The legal status of DR-DOS is a bit fuzzy. (You can also easily find versions of OpenDOS, which is a derivative.)

I can't imagine what sort of metric you could use to establish whether one processor is "better" than another when it comes to running any particular version of DOS. in the end, DOS is too simple for that to enter into consideration.

Socket 8 hardware is uncommon and sometimes expensive and there is very little reason to pursue it when cheaper alternatives that work just as well are available.

OpenDOS 7.01 is fully open source, and the wip patches add some very useful features. I can't speak regarding compatibility as I haven't tested it in ten years, but it is mature.

The Vesa Local Bus did not work with P5/P6 processors, so the Intel IntelDX4WB-100 is the best purely DOSy CPU.

dnewhous wrote:

The Vesa Local Bus did not work with P5/P6 processors, so the Intel IntelDX4WB-100 is the best purely DOSy CPU.

That is not the whole story, dnewhous. There are Socket 4 and Socket 5 boards (both for Pentium) with VLB. Also NexGen made a VLB board. And there were even 386 boards with VLB.
You see although the VLB was closely tied to the 486 bus doesn't imply it was limited to its architecture.

Also, the presence of PCI slots doesn't mean the machines weren't good for pure DOS. There are quite a few PCI graphics cards that are much faster than any VLB card ever built. A Pentium 133 for example is a fantastic computer for DOS games, just remember the Pentium-factor when Quake hit the market...

Of course one non-DOS OS -named Windows- really went through the roof when PCI became more common but that's more or less coincidence. In general the demand for computers grew fast and the companies spent much more on R&D and new techniques were developed even faster...

Just today I got two new old stock AT&T branded Socket 4 motherboards that have Vesa, ISA and PCI slots.
The OPTi Python chipset is a VLB/ISA solution and uses a bridge chip to implement PCI. So the PCI sits on the VLB bus. These boards are slower then the competition was back in the day but also more versatile. These are quite interesting boards.

The 486 was the last of the "pure x86 core" CPUs. If you want to go for "most pure x86/DOS system," a 486 would be the way to go. I'd even argue that the 486 DX 50 is the "most pure" since it's pre-multiplier - clock speed in is the same as CPU clock speed.

Pentium is where the actual processing core of the CPU starts to diverge from the outward-facing instruction set - the actual processor core, deep at its heart, is no longer "pure x86." Pentium Pro went even further, to the point that it ran 16-bit code (which the vast majority of MS-DOS programs are,) slower than an equivalent-speed Pentium! So no, I would avoid Pentium Pro (686/Socket 😎 for "pure MS-DOS machine." Note that a Pentium II is a Pentium Pro core plus MMX, and also fixed 16-bit performance - so if you were going to go for Pentium Pro, you might as well go for Pentium II.

As for "pure DOS" - even as late as the release of the Pentium II, there were still people running MS-DOS / PC-DOS / DR-DOS as their primary operating system. IBM released "PC DOS 2000" in 1998 as the "non-Windows latest release of DOS." And of course FreeDOS/OpenDOS released versions long after that.

It really depends on what you are aiming for. if you are aiming for "most modern stereotypical processor of the MS-DOS era," I'd go for a 133 MHz Pentium non-MMX. It as the top-end processor that was current at the time of Windows 95's release.

I don't know...
Dos is after all, an 16bit operating system. So in order to match the numbers beautifully, a pure 286 with 16bit-only cards would kind of like be a "pure" system. I don't know of any other 100% pure pc system, other than that. 32-bit begins with the 386, and I dont know if the 8086 was 16 bit externally.

The usual story is that an FSB speed of greater than 40 MHz breaks the local vesa bus. But I swear I once saw a 486-DX50 that had vesal local bus. This means some motherboard maker figured out how to fix the glitch. Does anyone know more about this?

DOS had a protected mode that is 32 bit and I have played at least one game that was protected mode.

dnewhous wrote:

The usual story is that an FSB speed of greater than 40 MHz breaks the local vesa bus. But I swear I once saw a 486-DX50 that had vesal local bus. This means some motherboard maker figured out how to fix the glitch. Does anyone know more about this?

DOS had a protected mode that is 32 bit and I have played at least one game that was protected mode.

Thrue about them excisting... There is a video on youtube. 😉
https://www.youtube.com/watch?v=KvQZ0yigTrk

"The usual story is..." - Well, what if "the story" isn't true? Read the VESA specs and tell the story again!

The specification ending at 40MHz doesn't imply that 50MHz won't run! Of course it does hurt stability and therefore wasn't recommended for the casual user. But in fact there are graphics cards that cope well when the bus speed is at 50MHz. I own a ET4000 and a 805i card and also a few other cards that work well at 50MHz.

The game becomes more tricky when you add other cards to the bus such as controller cards. Usually, SCSI controllers say no but I have some IDE controller cards that work along with the graphics card at 50MHz speed.
It also depends on the board and on the L2 cache timings. VLB systems are very sensitive when it comes to high clock speeds in conjunction with the L2 timings.

FGB wrote:

"The usual story is..." - Well, what if "the story" isn't true? Read the VESA specs and tell the story again!

I think you need to make a distinction between the CPU speed and the FSB (front side bus) speed.

The glitch is mentioned on the wikipedia,

As bus speeds of 486 systems increased, VLB stability became increasingly difficult to manage. The tightly coupled local bus design that gave VLB its speed became increasingly intolerant of timing variations - notably past 40 MHz. Intel's original 50 MHz 486 processor faced difficulty in the market as many existing motherboards (even non-VLB designs) did not cope well with the increase in front side bus speed to 50 MHz. If one could achieve reliable operation of VLB at 50 MHz it was extremely fast – but again, this was notoriously difficult to achieve, and often it was discovered not to be possible with a given hardware configuration.[3]
The 486DX-50's successor, the 486DX2-66, circumvented this problem by using a slower but more compatible bus speed (33 MHz) and a multiplier (×2) to derive the processor clock speed.

https://en.wikipedia.org/wiki/VESA_Local_Bus

The article states that the VLB was P5 compatible, not P6, so if you fixed the timing glitch the best CPU would be

Tillamook 0.25 µm 166–300 MHz 32 KB 66 MHz Socket 7 August 1997

Back in the day, I ran a VLB Diamond Stealth (S3 Vision) on my 486DX-50 at 50MHz FSB without any problems. Great video card.

I have just learned from looking at the specs for 1997 DOS titles on Moby Games, that the VLB issue misses the point. The top DOS titles used the Glide API and required 3dfx PCI video cards.

Hey, a good Pentium III is enough, those Tulatins and Athlons are overkill, that's about it for DOS computer.

Anonymous Freak wrote:

It really depends on what you are aiming for. if you are aiming for "most modern stereotypical processor of the MS-DOS era," I'd go for a 133 MHz Pentium non-MMX. It as the top-end processor that was current at the time of Windows 95's release.

Anywhere from 486 to Pentium 233 MMX is the DOS gaming era, basically the whole 90s.
The MMX with larger L1 cache can be too fast even for Pentium games and result in "speed bugs" or crashes.
I agree about 133 or 166 non-MMX is the defining Pentium for DOS gaming, even for the late 90s games when played at 320x200 resolutions.

Of course you can go for a Pentium 4 and play Quake, Tomb Raider and Duke3D in 1024x768, but that is not what was going on in the 90s.
P1-133 + 320x200 + CRT + Sound Blaster = where all the fun is. 😎