Emulator performance on GNU/Linux

[JucaBlues]

I am running the the emulator compiled from svn (revision 37 of the rev-beta4 branch) on Ubuntu 8.10 (amd64).
It is running very slowly.
Does it have good performance when running in Windows? On Ubuntu the performance is really poor. Any idea why?

[DaveyPocket]

The emulator runs fine under Windows.
I will have to try it under Ubuntu when I get the chance and post my results.

[nitrofurano]

where can we download a binary .deb or tarball (i386) of this emulator, and some roms (examples) to try? i'm not very lucky on compiling sources...

[uze6666]

To build check: http://uzebox.org/forums/viewtopic.php?f=8&t=153#p1286

For roms check Clay's demos: http://uzebox.org/forums/viewtopic.php?f=5&t=169#p1520

UZe

[louroboros]

I am experiencing very poor emulator performance in Ubuntu, as well.

That tutorial is very out of date.

Here's what I had to do to get the emulator built under linux:
1. Make sure you have the tools required to build...

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sudo apt-get install build-essential libsdl-dev

2. Then get the latest sources... (skip if you already have them)

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svn checkout http://uzebox.googlecode.com/svn/trunk/ uzebox

3. Now edit the file "uzebox/emulator/avr8.cpp" and replace ...

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#include "SDL.h"

... with ...

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#include <SDL/SDL.h>

4. Now build like so:

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g++ -lSDL avr8.cpp -o uzem

5. Test it out:

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./uzem ../demos/megatris.hex

The game is fairly responsive, but it's chewing %100 of one of my cores, and the sound is very choppy and delayed.

Let me know if there's anything I can do to help fix this problem, I'm excited about developing for the platform, but an emulator is crucial (and so is my operating system of choice).

[DavidEtherton]

g++ -O3 -lSDL avr8.cpp -o uzem

[louroboros]

I guess enabling optimizations improved performance enough to get it to run at close to %100.. but it seems like it's just barely getting there if at all.
I imagine it would still perform rather atrociously on older hardware...

Is there a way to see how close to %100 the emulator is running?

[DavidEtherton]

On MacOS at least, SDL performance is fairly terrible.

If you want to see how fast the emulator can run, turn off sound (-nosound I think) -- otherwise it slows down emulation to avoid flooding the sound buffer.

If/when particular video modes become dominant, it would be pretty simple to detect the timer interrupt and basically simulate the resulting screen much faster than running the video signal emulation code would be able to do it (roughly 90% of the cycles are spent on video and audio mixing, both of which could be done much faster with native code)

-Dave

[lightfoot256]

I noticed in the windows build I downloaded there were lots and lots of errors being printed in the console (especially on the v4 kernel) regarding bad memory access; This caused a big slow down of the emulator maxing my CPU to 100%; minimising the window under xp makes it run a little faster ( I guess windows doesn't have to render all those error lines) but it's still hogging a lot of CPU.

Might make sense to allow enabling/disabling of errors like that.

[uze6666]

Yes, this is a known issue. Most of the bad memory access are in fact generated by LPM instructions used as 3xNOPs. Problem is the Z pointer could point to invalid locations at that time but we don't care. Pragma is working on the emulator and has fixed this. Just don't know when he wants to publish his work.

-uze