VOGONS


Need help and advices for my new 486DX4

Topic actions

First post, by Deksor

User metadata
Rank l33t
Rank
l33t

Hi everyone.

I recently bought a 486DX4 system. I took the motherboard which is an Aopen/Acer AP43 to put it inside a cool looking case that I had laying around since a few month.

The jumpers weren't correctly set for the AM486DX4-100 that was in there (the 8KB Write Through model) so I changed that (it ran like a DX33 according to speedsys. But it felt slower than my real DX33 🤣) Currently there is 8MB of ram, but I will change that. I'm using a 2GB HDD from seagate that was manufactured in 1998 and a 24x CD drive from 1997. The sound card I'm using is a Sound Blaster 16 CT2700. The GPU is a matrox Mystique with 4MB of video memory and the network card is a 3Com Etherlink XL (3c905B-tx)

The HDD is divided in two partitions of 1GB. One contains nothing at the moment and the other one contains Windows 95 RTM

Win95 boots fast, but then it feels a bit sluggish. I'm using a resolution of 1024*768 with a 32 bit color depht, so this is probably why it is slow, but since I never ever owned a 486 this fast, I'm still asking ... is this normal ? don't the matrox mystique support GUI acceleration ? What is your prefered resolution for windows on a 486DX4 ? I have many PCI gpus that could go inside that computer I've got ATi, S3, Cirrus Logic, Trident ( 🤣 ) and even Nvidia video cards (the Nvidia is a TNT2 m64 so it's probably way overkill for that computer. Same thing for ATi. Even the matrox card is probably a bit too new for that), what would you pick ?

Doom and Duke 3D are really running better under MS-DOS (both games sometimes stutters due to HDD access. Probably because I don't have a lot of ram yet and that the IDE is working in PIO mode). This is a normal thing I guess, but there is a little problem with sound under some games ...

Duke 3D sounds fine under MS-DOS and Windows 95. Jazz Jackrabbit sounds fine under windows 95, but when I run it under MS-DOS, the audio quality decreases (just like it just ignored the config file) and I can hear a terrible hiss sound. You may think that is just an artifact due to low quality PCM, but then comes doom. Under windows 95 or MS-DOS, once the game is started, even if there is no PCM to play, I can CLEARLY hear that hiss sound. I tried to use the SET BLASTER command, but it did not help ...
What could be wrong ? it's like if the audio quality is high, the sound is great but if you choose too low quality audio, the sound card starts to create that hiss sound. Could bad caps be the reason to that ? I don't have this problem on my 486DX33 which has a sound blaster pro 2

I also tweaked the cache and memory timings in the bios :

The attachment IMG_20170221_171000.jpg is no longer available
The attachment IMG_20170221_171015.jpg is no longer available
The attachment IMG_20170221_171030.jpg is no longer available
The attachment IMG_20170221_171044.jpg is no longer available

Do you think that these can be improved, and if yes, how ? Can they be the reason to the few problems I had earlier ? Can I lower the PCI latency since the FSB is 33 MHz ?
My 486DX33 is an OEM, so I never had the opportunity to tweak these before

One last thing : I think I saw drivers for the SiS chipset, but I can't find them anymore. I think that this could improve the performance a little. Has someone tried them (if they actually exist 🤣 )

Thanks in advance for the help 😀

Trying to identify old hardware ? Visit The retro web - Project's thread The Retro Web project - a stason.org/TH99 alternative

Reply 1 of 28, by DonutKing

User metadata
Rank Oldbie
Rank
Oldbie

For your sound issue in DOS, I suggest going into mixerset, and setting mic and line in, and PC speaker volume to 0. If you have the PC speaker output on the motherboard wired to your sound card, unplug it as this can cause a lot of noise as well.

Can you post your DOS config.sys/autoexec.bat?

For Windows 95, 8MB is on the low side, 16 or even 32 will make it run a lot better.
I'd also suggest 16 bit color depth rather than 32, although I suspect more RAM will make a bigger difference.

If you are squeamish, don't prod the beach rubble.

Reply 2 of 28, by Deksor

User metadata
Rank l33t
Rank
l33t

At the moment I didn't tweak my Autoexec.bat/Config.sys. So I'm just using the "restart in MS-DOS mode" which means that it's just the basic win95 autoexec/config. This is a really fresh install ^^

I remember that my DX33 was a bit faster within win95 and it didn't have cache and it had also only 8MB of ram back then, it used 640*480*8bit resolution though, and I didn't have anything faster to compare with so I might be incorrect on this.

I didn't plug the pc speaker in the sound card (I don't think it had a header for it in fact ^^). Like I said, I did not tweak things a lot because I wanted to do this later and also because some of those things are quite new to me (I never used a real sound blaster 16, and I recently learned how to optimize RAM under MS-DOS, so I never really played with sound cards under MS-DOS except for my YMF724 last month)

However I knew about the noisy line input problem so under windows I muted it. I forgot about the microphone because originaly it's hidden. I'll change that tomorrow. I think I'm going to use another CD drive because the one I'm using right now makes a lot of "thinking noise".

But I don't think that this is the reason of the hiss sound problem as it does happen under certain circumstances either under MS-DOS or Windows

Trying to identify old hardware ? Visit The retro web - Project's thread The Retro Web project - a stason.org/TH99 alternative

Reply 3 of 28, by Rhuwyn

User metadata
Rank Oldbie
Rank
Oldbie

As far as your stuttering it could be that the hard drive is past it's prime. Maybe consider a CF Flash/SD card to IDE adapter. Or if you have some smaller hard drives sitting around swap um and just load up windows and one of the games that's stuttering and see how it goes.

Also agree that 8MB is a bit low for Windows 95, that could be the cause of stuttering in windows, but not in MS-DOS.

Reply 4 of 28, by Ampera

User metadata
Rank Oldbie
Rank
Oldbie

Windows on a 486 is almost useless. Unless you're playing solitaire, even games like SimTower will run absolutely terrible. All the games you're gonna wanna play on it are going to run in DOS, and anything else won't run well anyways.

And as previously said, 8MB is a bit small for a DX4. 16-32 is much better. My system is a DX4-100 (120Mhz) with 32MB of RAM (128MB possible) 2GB HDD (All for DOS), A SBAWE32, Diamond Multimedia Sealth SE VLB, and a DTC Dual Channel EIDE controller (VLB)

The neat thing about the machine is that in it's configuration, the VLB is faster than PCI (And it gives bonus geek points to boot)

But the thing is Windows is a resource hog. DOS is almost non-existent in RAM, and doesn't really use any processing power to speak of. But with Windows you have to draw all the graphics, handle the Windows backbone, etc. Even Windows 3.11 is not safe from this.

Also SSDs on old computers depresses me. Don't do it, I don't like it. It's ultimately your choice, but you lose the noise, and slowness of a hard drive. You may ask, Noise? Slowness? Why would I want this? It's like a fine wine or cheese. The bad and good make up the good. You can't feel joy without feeling a bit of sorrow, and from that having real components, especially with their frustrations will make the experience all more fun.

Reply 5 of 28, by Deksor

User metadata
Rank l33t
Rank
l33t

Where did you see I'm using an SSD ? ^^

I'm using a 2GB seagate from 1998

Edit : whoops didn't see that you were answering another post ... To answer that, I would say that a hdd from 1998 might not be the limiting factor here

I made two partitions in order to have a full DOS 6.22 on one of them and Windows 95 on the other. I know that windows isn't the most useful thing here, but I still like it. I'm still new to MS-DOS world even though I know how some stuff works in DOS, there are still many things I didn't touch at the moment. Having windows 95 here makes the transition smoother (and also because my DX33 is already a DOS 6.22 only system, I want something a tiny bit different 😉 )

Trying to identify old hardware ? Visit The retro web - Project's thread The Retro Web project - a stason.org/TH99 alternative

Reply 6 of 28, by Ampera

User metadata
Rank Oldbie
Rank
Oldbie
Deksor wrote:
Where did you see I'm using an SSD ? ^^ […]
Show full quote

Where did you see I'm using an SSD ? ^^

I'm using a 2GB seagate from 1998

Edit : whoops didn't see that you were answering another post ... To answer that, I would say that a hdd from 1998 might not be the limiting factor here

I made two partitions in order to have a full DOS 6.22 on one of them and Windows 95 on the other. I know that windows isn't the most useful thing here, but I still like it. I'm still new to MS-DOS world even though I know how some stuff works in DOS, there are still many things I didn't touch at the moment. Having windows 95 here makes the transition smoother (and also because my DX33 is already a DOS 6.22 only system, I want something a tiny bit different 😉 )

Then do a PC-DOS 2000 system. Or DR-DOS

Reply 7 of 28, by DonutKing

User metadata
Rank Oldbie
Rank
Oldbie

The other thing to check is that your turbo switch is enabled - if you've not wired the switch up correctly, its possible you have disabled turbo which is slowing the system down.

Your sound card hiss might simply be down to poor sound quality on Creative cards... the later single chip or Vibra SB16's had much better sound quality.

If you are squeamish, don't prod the beach rubble.

Reply 8 of 28, by Ampera

User metadata
Rank Oldbie
Rank
Oldbie

Turbo switches normally slow the system down. not speed it up. Unless this board is a rare one that does it in reverse, this normally won't have anything to do with anything.

Reply 9 of 28, by DonutKing

User metadata
Rank Oldbie
Rank
Oldbie
Ampera wrote:

Turbo switches normally slow the system down. not speed it up. Unless this board is a rare one that does it in reverse, this normally won't have anything to do with anything.

That's just arguing semantics. There were several different ways of handling the turbo switch and LED's. If he's done it wrong, he might have inadvertently put it in 'slow' mode.

If you are squeamish, don't prod the beach rubble.

Reply 10 of 28, by Deksor

User metadata
Rank l33t
Rank
l33t

No, I took care of that ^^
The cpu definitely running at 100MHz. Duke 3D is playable and once I press the button it becomes really slow. According to speedsys, the cpu then runs at 66MHz instead of 100 and it seems that the board loosen some timings making the ram even slower

Trying to identify old hardware ? Visit The retro web - Project's thread The Retro Web project - a stason.org/TH99 alternative

Reply 11 of 28, by PhilsComputerLab

User metadata
Rank l33t++
Rank
l33t++
Ampera wrote:

Turbo switches normally slow the system down. not speed it up. Unless this board is a rare one that does it in reverse, this normally won't have anything to do with anything.

Varies between boards. On some you need to close the pins for full speed, on others you need to open them.

YouTube, Facebook, Website

Reply 12 of 28, by Ampera

User metadata
Rank Oldbie
Rank
Oldbie

I agree, but the majority use the turbo switch where on is slower.

Reply 13 of 28, by Deksor

User metadata
Rank l33t
Rank
l33t

Added a 16 MB stick so this gives me 24MB now. Windows 95 runs definitely faster now. Doom and duke 3D stopped stuttering under windows, so my guess was right. However the hiss sound is still there under doom. I might record it.

Aren't the CT2xxx known to be less noisy than the CT1xxx ?

Trying to identify old hardware ? Visit The retro web - Project's thread The Retro Web project - a stason.org/TH99 alternative

Reply 14 of 28, by Frasco

User metadata
Rank Member
Rank
Member
Deksor wrote:

Added a 16 MB stick so this gives me 24MB now. Windows 95 runs definitely faster now. Doom and duke 3D stopped stuttering under windows, so my guess was right. However the hiss sound is still there under doom. I might record it.

Windows 95 running on a 486 isn't a smooth experience as long as I remember. Dunno if this apllies to the 133Mhz AMD version. Memory is not serving me well.
Maybe it is just a matter of tweaks in BIOS and Windows itself.

Call me nuts, maybe this is a nightmare, but Doom is changing the mixer volume levels of my sound cards!
(volume gets super higher!) I am the only one that finds that odd ?

*Wandering again*
HD's are the devil. Take Seagate Barracuda (firmware problems), Maxtor DiamondMax Plus, Seagate U series for example. Sure Samsung 160Gb Spinpoint is immortal and I like WD Caviar, but this is it! So CF is where I stand ! 😈
God, we don't have to suffer all that in life to know what good is. 😀

Reply 15 of 28, by Jo22

User metadata
Rank l33t++
Rank
l33t++
Ampera wrote:

Windows on a 486 is almost useless. Unless you're playing solitaire, even games like SimTower will run absolutely terrible. All the games you're gonna wanna play on it are going to run in DOS, and anything else won't run well anyways.

But, but.. I was playing Windows action games like Fortress on my 286 already. And Comet Busters (non-WinG version).. And Warpath..
Man, I even played Blitzer on that machine (or Dare to Dream!). I can't believe not even a 486 was good enough. 😳
Back in the days of Win95 I dreamed of getting my dads mighty 386 one day, a 486 was cutting-edge technology.
Not to mention 586-class machines, that stuff was still pure science-fiction to me. Even hi-end games like Myst
were said to require nothing more than a 386. Blitzer gameplay : https://www.youtube.com/watch?v=rS8i8dzGVd8

"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel

//My video channel//

Reply 16 of 28, by Ampera

User metadata
Rank Oldbie
Rank
Oldbie

By all means, I never said you CAN'T. I just said for most games, it's absolutely terrible. Ever try playing SimTower 800x600? Yeah, it doesn't work. And don't even get me started on higher resolutions.

No matter what version of Windows you use, DOS will ALWAYS have the better performance on pre P5 systems.

And CF cards just feel so artificial to me. You know what else is great? DOSBox. That's even better than having to spend money and time on old hardware. You can load your games instantly, and emulate them faster than even a P6 could do. No more need for crappy AT keyboards, now you can use soft, Cherry MX keyboards that are lighter on the hands.

My point is, once you start making substitutions, it removes the principle of the thing. You use old hardware to have the experience of it that you can't get from emulation, and without the clicking of the heads, the whirr of the platters, and the grunt of the data being read, there is just something missing.

Reply 17 of 28, by creepingnet

User metadata
Rank Oldbie
Rank
Oldbie
Frasco wrote:
Deksor wrote:

Windows 95 running on a 486 isn't a smooth experience as long as I remember. Dunno if this apllies to the 133Mhz AMD version. Memory is not serving me well.
Maybe it is just a matter of tweaks in BIOS and Windows itself.

Windows 95 will run fine on anything DX2-66 w/ 16MB of RAM or higher, though I have once seen a 386 DX-40 with a co-processor and 32MB of RAM run Win95 okay-ish. You also benefit if you have a accelerated IDE controller installed.

Ampera wrote:
Ever try playing SimTower 800x600? Yeah, it doesn't work. […]
Show full quote

Ever try playing SimTower 800x600? Yeah, it doesn't work.

No matter what version of Windows you use, DOS will ALWAYS have the better performance on pre P5 systems.

And CF cards just feel so artificial to me. You know what else is great? DOSBox. That's even better than having to spend money and time on old hardware. You can load your games instantly, and emulate them faster than even a P6 could do. No more need for crappy AT keyboards, now you can use soft, Cherry MX keyboards that are lighter on the hands.

My point is, once you start making substitutions, it removes the principle of the thing. You use old hardware to have the experience of it that you can't get from emulation, and without the clicking of the heads, the whirr of the platters, and the grunt of the data being read, there is just something missing.

I run SimTower on a 486 DX4-100 under 64MB of RAM in Windows For Workgroup 3.11 @ 800X600 @ 32-bit color and I have little to no performance issues whatsoever that make it painful to play. Some slowdown should be expected, and moreso when it's earlier windows as 95 on back had poor memory management by contrast.

As for substitutions - that should be EXPECTED in this day and age of using older hardware, especially when you go pre-Pentium.

I see it as there are at least two camps when it comes to this - one who wants something EXACTLY as it was in the time period, which is the most expensive, time consuming method to go down. While the experience is the most authentic this way, there are a lot of drawbacks to having a period-correct machine which includes parts availability, speed, capability, and it also limits the window of compatibility of the machine.

The other camp will need/want/prefer/be okay with substituting vintage tech with modern technologies because the convenience/time/higher trust of newer components and their lower failure rate (especially drives) outshines having a read/write/seek sound or a slight blur that makes your 320X200 16-color EGA DOS game look like it did on that shiny Compaq Deskpro in 1988. Plus, getting LCD monitors, DOMs/CF/XT-IDE, and non-cl;icky keyboards with adapters is much easier than getting the old stuff and dealing with the inherent dangers, costs, and time consumption therein.

DOSBOX is an option but people are going to run their software how they want to. TBH, DOSBOX kind of grinds my gears now because it's not a fix-all for everything DOS related. Certain software does not run correctly on it, you have the whole Aespect ratio of modern displays vs. the old DOS aspect to deal with if you want to go full screen, and the hardware provides a convenience of all these options already being pre-ticked in DOS because you don't need to tweak an INI file to configure a virtual machine, and game management is about the same - install a Frontend, then you have to build config files for everything you have.

As for me, I'm a part of the second camp and I do use DOSBOX on occasion when it's easier/more convenient/makes sense. But then I've been using vintage hardware for a long long time, before it was vintage and when it was Junk.

~The Creeping Network~
My Youtube Channel - https://www.youtube.com/creepingnet
Creepingnet's World - https://creepingnet.neocities.org/
The Creeping Network Repo - https://www.geocities.ws/creepingnet2019/

Reply 18 of 28, by DonutKing

User metadata
Rank Oldbie
Rank
Oldbie

Aren't the CT2xxx known to be less noisy than the CT1xxx?

No, its the later single chip Vibra models that are less noisy.... yours is still an original multi-chip design. Even the AWE32's are fairly noisy.
There's no obvious pattern to the model numbers, they are all over the place. The CT2800 is a single chip model with a real OPL3 and seems fairly common, so that's a good one.

Most non-creative cards have much better sound quality as well - eg ESS, yamaha, Aztech - so if you have one of those handy, try that and see if you still get the hiss.

If you are squeamish, don't prod the beach rubble.

Reply 19 of 28, by Deksor

User metadata
Rank l33t
Rank
l33t

I tested SC2K on windows 95 at 1024*768 and it ran fine. A bit on the slow side BTW, but the game was definitely playable. I also remember to have played simtower on my 486DX33 (I did put a DX2 66 at that time) under windows 95 at 640*480 and it was perfectly fine.

Sure I've got my pentiums and my K6-2, my pentium 2 and my pentium 3 for windows games, but I installed 95 mostly because I can and because that's what people would have done back then too. I remember that when I got my PCChips 486, it came with windows 95. According to a sticker on it, it originaly came with windows 3.11. My 486DX 33 also came with 3.11. Except for my 8088, I've actually never seen a computer that have been sold without Windows. I wasn't born in that era, so I don't really know how many computers had DOS only and how many had dos + windows, but like I said, from what I could get, nothing from the 90's had only DOS. Sure for gaming DOS is better, but I do like to use Windows too ^^

I do like to have period correct machines, and I have everything I need in general to build a period correct machine (even though this 486 isn't really period correct, due to the really fast CD drive and to the munch newer HDD, but that's just because they were the first to come out of my pile of hardware, but I understand why some people prefer to do substitutions. But yeah, I still have 50+ (untested) HDDs ranging from a few hundreds of megabytes to ~80GB so I don't think I'll need to substitute the HDD for a flash card right now. Though for my laptops, flash cards are a good thing to use imo. Do note that this build is NOT finished yet (and since the CD drive is making a lot of noises, clicks, etc, I will definitely swap it out for another one).

Can we go back to the main subject ? I'm really worried about that sound card ...
DonutKing mentionned a mixer for SB16s under MS-DOS. But how do I install/use it ?
Though I tried to mute everything but midi and wave under windows and unfortunately it didn't help 🙁 but having the possibility to control voices under MS-DOS interrests me. The card in itself makes some noise even when it's doing nothing so the more I look at it the more I think that this is caused about bad caps (even though some of the noise might not be "fixable"). I might check the PSU too. This is still odd to me that the hiss sound isn't happening in every situation

if you have one of those handy, try that and see if you still get the hiss.

I have many sound blaster clones made by different companies. I've got a yamaha YMF719 which is not used in any of my builds at the moment. I do have a vibra CT29xx, but unfortunately this one doesn't have an OPL3 chip (and it's not built in the main chip either). It that really how that CT2700 card is supposed to sound ? Why when using higher quality samples, the hiss sound disappears ? When I play a standalone midi file, it's fine, when windows does it's boot sound it's fine, but when the quality of the samples is lower, the hiss sound appears like I said. Doom seems to use low quality samples. Under duke 3D, I can choose which quality I want to use and so I took the highest and I don't have this problem. With Jazz Jackrabbit, when the quality is set to highest, the hiss noise doesn't appear, but when the quality is set to lowest, I can hear that hiss noise.

Trying to identify old hardware ? Visit The retro web - Project's thread The Retro Web project - a stason.org/TH99 alternative