Nice...

I settled for a Pentium 200 chip on a Super Socket 7 board for my "slowdown" Retro machine. It has onboard cache which can be disabled in the BIOS.

With L1 and L2 cache disabled I get the equivalent of a 386DX, Wing Commander runs really well. However I found that the game is a bit too fast when there are no ships / debris. And when the action heats up it becomes slower / easier to play.

Wondering if an ISA video card would smoothen things out (Not as fast when there is little action so to speak) or if this is just how this game plays...

When I turn on L2 I get 486DX2 equivalent machine.

I have found ICE and ICD to be a godsend on my 486DX2. I don't even bother with the turbo button, I just leave it on all the time, and just use a batch file with these utilities to enable/disable internal cache for particular games that need it. Games like Wing Commander, Scorched Earth, Test Drive 3 all need it disabled to play properly.

These Pentium slow down projects are great! I particularly like the use of a turbo button on the skt 5 mobo. I don't have any skt 5 mobos, but it's possible I may have one or two skt 7 mobos with a turbo button header on them - I'll have to check.

Re: Wing Commander on the P200 system, Mau1wurf1977 have you tried a slower chip such as a P100, in order to slow down this game a bit further?

The CPU clock speed doesn't matter once you disable the cache. What matters is the FSB and what chip you are using (Cyrix, AMD and Intel all behave a bit different) and what architecture.

The closer your hardware is to the real thing, the less "slowdown" you get. E.g. a 486 without cache doesn't slowdown as much a Pentium without cache and this gets worse on a Pentium II and Pentium III.

The Pentium IIs and IIIs usually have no motherboard cache, so it's either super fast, or slow as a 386SX with no steps in between. IMO a 486 is most versatile with with Turbo, Cache and FSB options. However I chose Super Socket 7 because of the ATX form factor...

There is scaling from 66 to 100 MHz FSB, but AFAIK you can only do this on a Super Socket 7 board anyway.

Here some examples. With L1 and L2 off, even the FSB doesn't matter. It gets you a 386DX and that's it. No matter if it's a Pentium 100 or a K6-2 550.

With L2 enabled we do see good scaling through the FSB however.

I have to say I was really lucky with the Super Socket 7 stuff here in Australia. When I was looking for some options there happened to be 3 SS7 boards on Ebay Australia and I grabed 2. The one I am now using has 3 ISA slots and works really well.

Currently working on options to record VGA output. I got the capture cards, just waiting on a bunch of cables and adapters.

Next project will likely be a real 386 and that should give me more insight into what effect a fast AGP card has on a "slowed down" Pentium...

^ Awesome. You've just given me a thought. I had a look at my Asus P2B slot 1 mobo, and it has 16 different FSB settings printed on its PCB. They range from 66 to 150. If a "slow" P2 (eg 233 MHz), or a Celeron (eg 266 MHz), or one of those "under-clockable" P2 chips were used, I wonder if you would see some interesting and useful "slow down" scores?

Edit: Oh sorry. I see what you are saying. The P2/P3 mobos are not as good as Skt 7 mobos, because of the way their cache works.

Edit 2: Yes I remember. I disabled the Asus P3 cache, using a very fast CPU and FSB. I couldn't get any faster than a 386 DX system. Therefore, using the P3 system, it is not possible to get the speed equal to any kind of usable 486 system.

With Slot 1 I can save you the time and effort 🤣

Having no L2 cache (it's on the chip and gets turned off with L1 so you can't enable them separately) it comes down purely to FSB and what Ram you are using (CL2 or CL3 and other ram options).

A 1 GHz PIII with 133 FSB will give you ~ 386SX25 once you disable L1 cache. From here on you will just get slower results with other CPUs. 100 MHz FSB ~ 386SX20 and 66MHz FSB ~ 286.

Slot 1 system is the least flexible system for "slowdown" projects. A modern Phenom 2 or Socket 1156 board has more options (FSB 100 - 200 MHz, CPU Multi as low as 1x to whatever the cpu supports). However they don't have any ISA slots, otherwise I would use my Phenom 2 as a Retro PC 😀

Not kidding you it booted up with a FSB of 100 and multi of 1x (100 MHz) and it benched like a pentium 🤣

EDIT: Yea basically the mainboard cache gives you another variable to tweak the slow down performance and a Turbo Button gives you a third.

I don't think Malik has an option to disabled / enable the mainboard cache, because that would also be quite interesting. On my SS7 board there is a BIOS option for L1 and L2 which is very handy.

SS7 mobos seem to be the best for slow down projects. Malik's Skt 5 mobo is awesome too. The SS7 mobo I tested a few weeks ago even had an FSB option as high as 140! Before SS7 disappeared at the end of the 90s, the quality was good on some of them.

Re: 486 and the AT form factor. You can get AT to ATX power adapters, but I guess you prefer the ATX mobos because the cases are easier to find?

Edit: Actually, I think Malik's Skt 5 mobo is better than a SS7, for slow down projects. What do you guys think?

I got the AT to ATX adapters! Actually 2 of them 🤣

Socket 5 or 7 shouldn't really matter much. What it boils down is what BIOS option your board has and if it has the ISA slots you need. E.g. the second SS7 board I have (Aopen) doesn't have a L1 BIOS option which is quite a pin. It also has "only" 2 ISA slots and a weird layout with cables going to funny areas.

Do you know if a ATX power supply fits into an AT case? Do the mounting holes line up?

I also need to find a better mouse or mouse driver. I have a Samsung optical PS/2 mouse but it behaves funny. When you move the mouse slowly it goes only a small distance, but when you move it a bit faster it goes way further. It makes it unusable really. I tried the speed settings of the driver but that didn't do much...

Are there optical mice options on a 386 with serial port?

True, the Turbo Button is very useful. My Pentium 133 for instance, get's transformed to a 486DX2-66 (relatively speaking) instantly by just pressing the button. The best part of this button is that you can do the transformation WITHIN a game.

An example for this kind of usage is, slowing down certain timing related action sequences, especially when that sequence comes in an adventure game.

EDIT: Another example is like games like Ultima VI mentioned above : You can turn ON the turbo button when you need to traverse large areas, and then turn it back off when in combat or when in town.

486DX2-66-specs is still fast for older games though, but then, the internal cache (or it's lack of) comes to the rescue, literally transforming the system to a 286 AT or an XT.

I didn't pay much attention to disabling the external cache since I didn't notice much usefulness in this when I checked out the slowdowns in my actual 486DX2-66. (The change was very minimal, and it added the extra burden of disabling or enabling it in bios.)

EDIT: This motherboard has 3 PCI and 4 ISA Slots.

Regarding ISA that's another thing I will try to find out.

When you slow down a Pentium and you get a CPU benchmark which lines up with a 386DX-25 but then you play a game or run 3DBENCH you will find that it's actually quite a bit faster.

So I'm thinking if you use an ISA video card like a Cirrus Logic or Tseng which where popular in the days then you should get a very close representation of a true 386DX25. I found that with a high performance AGP video card certain things which "run off the video card" seem to run way to fast.

Definitely something I will look into, just need to score a cheap ISA video card 😀

Re: ATX PSUs - unfortunately, I don't know if one will fit inside an AT case. Re: optical serial mice. My guess is that they do not exist. You have jogged my memory about PS/2 mice behaving a bit oddly. It could be a systems win9x resource issue, in conjunction with a driver issue. Have you tried using a HDD with just pure DOS 6 on it, as opposed to Win9x?

I am testing some optical PS/2 mice at the moment. One of my many "retro mistakes" is to standardise on serial mice. I did this because I briefly tested a PS/2 mouse, and didn't like its slow responsiveness. However, I later learned that you can increase the mouse sensitivity using the /R switch with ctmouse.exe. Now, I can see the benefit of using optical PS/2 mice instead of serial mice.

Malik, to be able to alter the system speed in-game is a cool luxury that I wish was more readily available to us retro gamers! 😀 Of course, DOSBox can do this very nicely! 😎

Only Dos 6.22 on my system. No windows whatsoever 🤣

I will try another mouse driver...

I bought a PS/2 to serial adapter off ebay but it doesn't work. I can get the driver to load and the red light goes on, but the mouse doesn't work. I also bought a PCI PS/2 card, but that would only work on a 486 machine as 386 didn't come with PCI...

@ Mau1wurf1977 & RG100 : Yes, an ATX PSU will fit in an AT casing. This current one is using the ATX PSU with the ATX to AT converter cable.

To fix the ATX PSU, though, you need to turn the PSU upside down. Otherwise, the screw holes won't match with the openings at the chassis. But when it is upside down, you'll be surprised to see the perfectly matching screw holes! (It's like the feeling when Watson is amazed by the sudden enlightenment by which Sherlock brings about, about something which was clearly missed just moments back!)

@Mau1wurf1977 : Unfortunately ISA video card may not help in slowing down the particles, as you have seen in Wing Commander I. That is more of CPU-dependent.

Applications which rely on pure 3D like 3DBench though, might give a higher results, because they rely on the graphics card's prowess.

But ISA graphics and PCI or VLB graphics may have differences in scrolling movements - like in 2d-platforms, screen scrolling in Sierra's adventure games, scrolling screens while moving across large areas like the Ultima series, etc. - where VLB and PCI maybe faster.

My 486DX2-66 and this current Pentium 133 produced very favourable results, as seen in Wing Commander I.

I find better slowdowns with this Pentium because when both the Turbo and Int. Cache are off, the XT-AT like speed is much better than the 486, when I tested the scrolling and moving speed in Interplay's Lord of the Rings vol.1 (old RPG-ADV game).

Ok that's good to hear!

EDIT: Ok I tried another mouse driver from Logitech and this one works perfectly. It doesn't have that isse CTMOUSE gave me...

It loads a bit longer and likely needs more memory but this doesn't bother me.

You can download it here: http://www.uwe-sieber.de/util_e.html

Driver loads like this:

@ Malik

Yea my thinking is when you have the cpu performance of a 386 and the video performance of a 386 you pretty much have a 386...

Memory throughput is still faster but with a slowed down CPU this shouldn't matter I think.

I looked for ISA video cards and they all come from the US. Will keep looking for something local. One day I will get real 386 and 486 parts anyway, so an ISA video card is handy to have around.

I just tried those logitech mouse drivers. This is curious - after running mouse.exe, I query the PC's memory status with mem /c /p, and I cannot see the mouse driver, and I also cannot determine if any memory has been used by the mouse!

Also, there is a useful mouse.exe switch called S, and you use it with a number between 0 and 10 for the mouse speed. S10 makes the mouse very fast. Unfortunately, there is a downside to this great Logitech driver, and that it will not function with my 2 different serial mice. It only works with my 2 different PS/2 mice.

Thanks about the mouse speed option, very handy...

Pretty happy with my Retro PC now. Everything is working fine and next up will be trying various VGA recording devices and seeing which one gives me the best quality...

This project just never ends 🤣

Mau1wurf1977 wrote:

This project just never ends 🤣

Hehe! That's the great thing about this hobby. Keep up the good work! 😀 Everyone.

A Trident 1MB ISA VGA card (TVGA8900C) is coming my way soon. I'll try posting some of my findings later.

That would be awesome.

Especially interested in subjective impressions which can't be measured in benchmarks...