Okay, I have to ask it now: NewRisingSun do you agree with me?

I'd rather not.

But it is true that unless DosBox specifically accounts for delays due to bus and video memory access wait states, videomemory-to-videomemory transfers such as scrolling in Sierra games are going to be faster, ceteris paribus, than on a comparable legacy machine.

They are right, video memory is too fast.

I'm sure it ran great on your computer, but as NewRisingSun said: ISA botterneck, slow video RAM. If someone were to program a speed cap in, I KNOW, the sound wouldn't skip, even on my old beast. The reason it skips on mine though, as I'm sure our friend will agree, is because there's no bottleneck on the video holding it backing from getting in the way of the sound. And YES, DOSBox does show these particular transitions way to fast. You've just adapted to them. I know I was startled by the dissolve transition the first time I played a game using NewRisingSun's patches. I kept going "Wow, there was a dissolve THERE?"

slow video RAM

It's not that the video RAM itself is slow, but that the graphics card hardware needs to access it all the time to display its contents on the monitor and is given priority access over the host CPU.

The reason it skips on mine though, as I'm sure our friend will agree, is because there's no bottleneck on the video holding it backing from getting in the way of the sound.

The speed of the emulated video hardware has absolutely nothing to do with your sound skipping problem.

Music speed depends solely on the emulated 8254 programmable interval timer. It is completely independent from the emulated processor or emulated bus speed. If it is not constant in your emulated machine, your emulating (host) computer is not fast enough to maintain the emulation at the desired speed.

I think he should've taken your first piece of advice NRS. hehe

The video hardware emulation has absolutely nothing to do with your sound skipping problem.

I suppose, if you say so. It just seems odd that only the transitions cause it the sound skip. It's not like they're that stressful on the CPU, 286's performed these transitions back in the day. Video is the only thing left to impede it, I would think.

----
Oops, I hate when someone answers a question, and I completely misunderstand the answer, and I keep on posting. You're right, it's probably something else. Never mind. Here I go and accuse dh4rm4 of not fully reading my posts, but then I do the same.

I have just run SQ1 under DosBox 0.70 on an old Pentium II with 450 MHz from 1998, and it runs fine without frameskip and without any sound skipping whatsoever, even during the scrolling. (Earlier versions of DosBox didn't run so well on that machine.)
Strange that even a far crappier machine than his doesn't have his problem.

Oh probably, I almost laughed myself silly when I stably got almost 16000 cycles on my 1.1 GHz P3 win98, when this crappy 2 GHz can only get about 9000. I blame XP and Norton AV.

One of these times I really will give Norton the boot, but oh, it's so hard to not use things you spend good money on, even if they are crap.

If you'd like to check here is a CVS build with limited VGA memory speed.

http://home.arcor.de/h-a-l-9000/test/dosbox_memdelay.zip

Most notably in the panic demo (the part after the fractal mountain) and Terminal Velocity (when displaying the two first logos).

If you'd like to check here is a CVS build with limited VGA memory speed.

That is PERFECT!!! Thank-you so much! That is EXACTLY what I wanted!

Good. Thread closed.

clean up and reopened.

lazerith if you are ever looking for a much much MUCH better and more secure virus/adware/malware/rootkits/firewall protection then spend 100$ AUD on "trend micro internet security 2007"... well worth your money. (shelf price)

3 Users - 2 Years - Digital Downloadable (US$64.95) [got this from there site]

franpa wrote:

lazerith if you are ever looking for a much much MUCH better and more secure virus/adware/malware/rootkits/firewall protection then spend 100$ AUD plus whatever on "trend micro internet security 2007... well worth your money.

3 Users - 2 Years - Digital Downloadable (US$64.95)

Thanks, I'll check into it.

Okay, I did some testing and here's what I found:

SQ1VGA at 25,000 cycles
In standard build there was a cut out in the sound during the previously mentioned screen transitions. I increased the frameskip to the max, 10, but it had absolutely no effect on the sound.

In Hal's build with video memory adjustment, there was no cut out on said transitions.

There was still some minor popping elsewhere in both versions, but that's because DOSBox is clocked faster than my computer can handle. But we already know this. To be specific: I have intentionally overclocked DOSBox.

DOOM at 50,000 cycles
In the standard build, when I move around, my movement on screen is fairly smooth, but the music crackles and pops. Again, I increased the frameskip to the max, 10, but it had absolutely no effect on the sound.

Using Hal's build, the video was slightly sluggish, but the sound was absolutely clean, with no popping while moving around.

In both games I had selected Sound Blaster/AdLib for sound. Also know: I have the DOSBox settings for both Sound and OPL rates set at 48000. Again, I have intentionally done this to push my computer to the limits.

I could be completely wrong, because I don't know what all Hal has changed in his build, but I think this seems to give both games a little bit more stability by having a restricted video speed.

My proposed experiment:
Now that I am being taken seriously, I would like to ask others with newer machines to humor me by doing the same thing. Take an FPS or any demanding 3D game of your choice (preferably with FM music) and play it in both builds.

1. Purposefully overclock the standard build of DOSBox to the point that it causes negative side effects in other areas of the game (like skipping sound).

2. Run the game in Hal's build of DOSBox. Clock the CPU cycles at the same speed. Because you are using a build with limited video memory, the video will probably have a minor lag during movement, which is to be expected. But, are the other negative side effects still there?

If the video speed of Hal's build could be adjusted up high enough, while still being limited, the movement in the game should be perfect. So my question is, could adjustable video speeds be used as a smoother, cleaner, and possibly more stable alternative to frame skipping?

I don't know how difficult it would be to add customizable video speeds to DOSBox, but I think it has potential to be a good thing, if implemented correctly. I could be wrong about everything, but if I'm right, I think it's a least worth considering.

As I stated previously the current .0.7.0 is PERFECT (sometimes even better in that it plays aspects like streamed/compressed video even more smoothly) in really demanding games like Wing Commander III and Magic Carpet II where later generation VL-BUS and PCI cards were becoming more commonplace for the PC. I'd say that Hal's build would be a detriment to games of that generation - purely because DOS machines of the day could barely keep up with them properly and people's expectations were a lot lower. Also, what is perfect really other than a value judgement?

Case in point is Wing Commander III - there were people complaining of pops and clicks in the voice/movie soundtrack so a patch was released for DOSBox. Yet, in truth that's exactly how the game sounds on real Soundcards of the day complete with pops and clicks. So these patches move the emulation away from sound emulation 'perfection' and closer to what we expect these days ' - crystal clear CD Audio...the same holds true for framerate of the emulation speeds and so on...

dh4rm4 wrote:

I'd say that Hal's build would be a detriment to games of that generation

That's why if such a feature were to be added, it should be optional and adjustable.

Edit: After furthur testing I've discovered it probably wouldn't contribute enough of a speed increase to be worth implementing solely for the reason of a frame skip alternative. It seemed to have little effect on many the games I tested. However, I do still think it would be nice to have the option to adjust the speed to custom levels for the sake of Sierra's old games and for the few other games that would benefit.

Using Hal's build, the video was slightly sluggish, but the sound was absolutely clean, with no popping while moving around.

That's because the delay subtracts from the cycles. With the delay you have to increase the cycles higher to get the same CPU speed as without. But your computer can handle those higher cycles too since the delays are artificial and do not really take up the same time on the host. (Ever looked at the CPU usage in your Task Manager while running DOSBox?)

Run the game in Hal's build of DOSBox. Clock the CPU cycles at the same speed.

That way you only get a slower DOSBox (see above).

About your SQ1 sound issue: You say the transition should take about a second but in DOSBox it's only a fraction of that. The operations required for the transition thus are not distributed in a whole second but in that fraction, which means you get a peak in host CPU usage. Now if the peak hits 100% of CPU usage it means sound processing starves till the peak is over.

Case in point is Wing Commander III - there were people complaining of pops and clicks in the voice/movie soundtrack so a patch was released for DOSBox. Yet, in truth that's exactly how the game sounds on real Soundcards of the day complete with pops and clicks.

Did you have some crappy Aztech sound card or something? They'd never have released WC3 with such a bug.

Hal's build would be a detriment to games of that generation

Just set your cycles higher and you should get about the same performance on the same computer.

There is a problem though - it might have to differ between ISA/VLB/PCI speed class - like in Tyrian in Pentium graphics mode I can set 250 000 cycles and it still only uses about 30% of my CPU and feels sluggish.

h-a-l-9000 wrote:

Did you have some crappy Aztech sound card or something? They'd never have released WC3 with such a bug.

No, not at all. DX4 100, SoundBlaster 16, GUSMAX, 16MB RAM - among other devices including that faux golfclub that came with a special version of Access Golf and a Thrustmaster T1 that I still own to this day. At the time I was both in IT sales/consulting and a games journo and the original game sounded (white etc) noisey as hell compared to modern games, with their studio recorded fx and noiseless compression/ADSR compressed sound. What I'm describing is less of a bug and more a cause of multichannel mixed audio at a time when CPU power was low, soundcard noise floors were high, while hz rates were low and lossless audio compression/mixing with mixed bit rates whilst driving really advanced 3D gfx and Midi output wasn't something really feasible.

Also, ORIGIN did released some games of that era with some terrible bugs - especially when EA got their claws in and started pushing release schedules harder and faster. Strike Commander still remains as one the greatest unfinished messes ever released in my humble opinion.

Music speed depends solely on the emulated 8254 programmable interval timer. It is completely independent from the emulated processor or emulated bus speed. If it is not constant in your emulated machine, your emulating (host) computer is not fast enough to maintain the emulation at the desired speed.

well, if the video is not limited, what stops the video from hogging resources that could be used instead for sound stability?

im sure most dos games don't need a fast video card to get the video output to be smooth.