Good to know!

Just out of curiosity, how much of a slowdown do you get on your 1 GHz cpu if you disable the internal cache?

If you could compare it to an older machine (e.g. 386 20 MHz) that would be awesome...

It could also be your CPU overheating (even though it's not really very taxed running those older games). You could try reseating the heatsink with a new layer of thermal compound.
Other then that just make sure your HSF is adequate for your P3-1000. Your HSF should be able to handle cpu's with around 30W of heat dissipation.
Usually a 60mm aluminium heatsink with a thicker bottom and 60mm fan should be enough.

If this is not causing the lockups, then please disregard! 😉

Right, I'm particular about my cpu temperature. And I'm using a cooler-master socket 370-compatible heatsink with fan, which i bought new along with the thermal paste. The contact with the paste is even and good.

From the BIOS, I can see the CPU temperature at 39°C after an hour of use. I never seen it cross 40°C. And I added 4 silent fans, which I individually picked up myself to keep the inner atmosphere (relatively) cool. The system temperature lingers around 36 - 38°C.

Using a 500W PSU with the -5v rail for use with my LAPC-I.

I have yet to try disabling the cache for this machine. I'll try it soon.

memtest?

Memtest86 v2.10 test done : no problems detected.

I have yet to try with the 100MHz bus speed. But since the 66MHz works well, I'll just leave it that for now. ( I remember last time when running a DFI P2XBL mobo - BX440 chipset, which was running at 100MHz bus speed [100x4.5 = 450MHz] had no problems. Current DFI CA6` is based on the VIA Apollo Pro 133 chipset.)

Malik wrote:

Right, I'm particular about my cpu temperature. And I'm using a cooler-master socket 370-compatible heatsink with fan, which i b […]
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Right, I'm particular about my cpu temperature. And I'm using a cooler-master socket 370-compatible heatsink with fan, which i bought new along with the thermal paste. The contact with the paste is even and good.

From the BIOS, I can see the CPU temperature at 39°C after an hour of use. I never seen it cross 40°C. And I added 4 silent fans, which I individually picked up myself to keep the inner atmosphere (relatively) cool. The system temperature lingers around 36 - 38°C.

Using a 500W PSU with the -5v rail for use with my LAPC-I.

I have yet to try disabling the cache for this machine. I'll try it soon.

Doesn't sound like your cpu is overheating there 😉

Memtest could be an idea to try. If you're in a hurry you could switch some RAM around (if you have a bad stick and 2 or more in your machine, relocating might make it lock-up later, then you can be fairly sure it's the RAM).

Other then that, you could try playing a more demanding game on your rig thats "time period-correct", just to be sure it is not a hardware problem. If something like Unreal2 doesn't lock up your system then logic will point that it's probably not a 'basic 'hardware issue (motherboard, RAM and CPU).

If Unreal2 also locks your system up, this is something you could try:
It might be possible your motherboard can't cope with the cpu at 1000Mhz. The best way to test this is by (temporarily atleast) installing a slower Coppermine of, say, 733Mhz.
This is just to test if the motherboard itself can handle the 30W the Coppermine uses.

Another idea, could it be possible your PSU isn't providing enough power on the -5V rail? (unlikely, but not impossible I reckon). Still wouldn't explain your rig running flawless when underclocked though...
Try playing the same game with the soundcard removed (or disabled).

Edit: 🤣, I needed more then 17 minutes just to type my last response haha!

Hmmm...I have noticed this only with the said dos games. If i leave the machine running, nothing happens. I can play System Shock 2, Revenant and Escape from Monkey Island without any problems.

In that case it might point to the soundcard + PSU.
Have you tried without sound with either the card disabled or removed?

Edit:I realize this shouldn't be a problem since your system runs fine underclocked. It's just that I'm running out of ideas 😜

If it still locks up with the card disabled/removed, it may be a software issue or, if the lock-ups only happen when using your soundcard, the -5V rail of your PSu...or the card itself (it better not be the soundcard I hope!!!)

Are we sure the mentioned games are CPU-speed-proof?

h-a-l-9000 wrote:

Are we sure the mentioned games are CPU-speed-proof?

Nope. Was just trying to exclude that it's a hardware problem. No point trying to fix something with software if the problem is with the hardware 😉

Edit: woops, should've pointed out that IF it was a hardware problem that it would most likely be that. It doesn't have to be a hardware problem.
Thanks for pointing that out, H-A-L 😉

Alright, I tried increasing the bus speed to 100MHz (100MHzx7.5=750Mhz). The problem came up again!

I reduced it (bus speed) back to 66MHz, and the problem is gone, no more.

I can quickly test this because Descent will hang as soon as a level is started. Descent refused to start the level. Immediately when the level appears, the system locks-up, whether with the graphics intact, or the screen going blank. Keyboard fails to respond and I have to press the reset button.

Little Big Adventure (LBA) is more difficult since it takes upto 10 minutes to see the problem crop up, but no more than that. But still, I played for about 6 or 7 minutes and it hanged with frozen graphics and including the system and keyboard, when I increased the bus speed to 100MHz.

Again, bringing down the bus speed back to 66Mhz, removed this problem. Played LBA for 15mins till I stopped to write this.

Something to do with the bus speed, probably a PIII, with the presence of Apollo Pro 133 chipset. Or maybe it's just with my motherboard. But still, strange, since this only happens with these games that I have tested.

I can play other dos games, - all the real-mode games for hours without problems - All Sierra games, Heart of China, GODS, etc.

And no problems with any of the windows games that I have played with.

The only trigger factor I can pick out is the bus speed. Reducing it to 66MHz removed the problems.

EDIT: Also, I have to point out that the problem persisted in any memory configuration - regardless of types - EMM386/QEMM386/HIMEM/QHIMEM/Basic Himem with no other TSRs etc.

And DOOM (and it's engine family) has no issues.

Do you have another PSU to test your system with? Maybe the 500W one is defective?
I've seen PSU's with bulging caps inside. And please be very carefull when opening up PSU's! It's best to leave it on the shelf for a couple days before opening one up.

Exchanging the PSU will help to rule out the problem is caused by the PSU.
Just to be safe, use one that has -5V. Any brand 300W ones should be more then enough to power a P3-1000.

And when you change the fbs, you also make sure that the other busses are running within spec, right? (no overclocked PCI bus etc)

Edit:Btw, could you specify what hardware and OS you're running?

Edit2:Like H-A-L mentioned, will those games run fine on other but similar systems?

Try different ram!

Could the IDE controller be unstable at 100MHz?
An extreme longshot but might be worth a try if you have a spare lying around.

ux-3 wrote:

Try different ram!

He did run memtest and all seemed fine. Still a good suggestion, maybe the RAM just doesn't like the motherboard, or several RAM's don't like each other.

You do have PC133 installed, right?
Another suggestion could be to install modules with same densities.
Best way to test this is by installing a single 256 module just to be sure.

Hmmm...the PSU being used in this system is a new one, though. About 3 months old. Still, I can't rule out a defect. I'll try changing it some time.

I've tried with different RAM sticks - both PC-100 and PC-133. Same result.

EDIT: For all these trials, I use only single-module PC-133 256 RAM and PC-100 128MB RAM.

IDE cable? Haven't thought of that. Should try that one too.

UPDATE:

Taking a cue from my main system*, I tried beating around another bush :

DOWNGRADED the BIOS - about 5 releases backwards.

And guess what - I had left Little Big Adventure running for about 20 mins, and.............. no more lock-ups!! Even at the bus speed of 133MHz!!

My hybrid system in discussion :

The top drive is a Teac CD-56E 6x CD-ROM. For quiet and continuous uninterrupted DOS gaming. Unlike the newer faster drives where you have to wait for the spin-up and have to put up with the noise too.
The lower one is a newer Lite-on DVD+RW used for installation, archiving copying etc.

I forgot to mention that in addition to the LAPC-I, I also have a Audigy - for digital-only music in Win2k and WinME. Games like Escape from Monkey Island, Revenant, System Shock 2 etc. use only the optical audio out from the Audigy drive.

[* - My main system - ASUS Striker II Formula's BIOS had to be downgraded several revisions back to maintain the concurrent 1333MHz bus speed and the 1066MHz of the DDR2 Ram (Kingston HyperX PC-8500 sticks). Otherwise I had to increase the bus speed to get the DDR2 up running at 1066MHz, which in turn makes the system unstable.]

Man I had TEAC CD drives back in the day!

You might already know this, but TEAC had DOS level drivers that allowed you to set the speed of the drive. This even worked for 8x and 12x drives AFAIK.

There was a parameter which you had to add in the config sys driver line and you could "turn it" into a 4x drive without any up and down spinning 😁

They also had these "super fast" CD trays that shoot out...

I remember buying a 6x model together with the game "The Dig". Whatever drive I had before was stuttering during the video sequences of that game...

Malik wrote:

I tried beating around another bush :

DOWNGRADED the BIOS - about 5 releases backwards.

And guess what - I had left Little Big Adventure running for about 20 mins, and.............. no more lock-ups!! Even at the bus speed of 133MHz!!

Very interesting, and congrats! Is this the successful solution to the problem?

Just to be 100% sure, you might want to upgrade the BIOS again and see if the issue returns? Maybe it was some setting that got changed that actually solved the issue.

Any chance that bios came with a changelog giving you a hint as what might cause the lockups?