hectoByte - a 128 byte intro released at Outline 2012

[Tjoppen]

I forgot to post this a while back. It's a 128 byte intro (demo) for the Atari 2600. It placed 2nd in the 128 byte competition at Outline 2012.

 

It doesn't work correctly in Stella, so you need to use MESS (with the 4k ROM) or a real machine (via say Harmony).

 

http://www.youtube.com/watch?v=s91ujoAgdkc

 

Links:

http://www.pouet.net...php?which=60483 - pouet page

http://www.acc.umu.s...s/hectoByte.zip - release, including source code

[+Random Terrain]

Your video just gave me a special form of epilepsy that makes my pants fill up with tooter pudding every time the phone rings. And I don't know how, but thanks to your video, one of my fillings is picking up a local radio station whenever I yawn. You wouldn't think it would be a problem, but the volume is loud, so I violently snap wide awake with every yawn and I can't get to sleep.

[Tjoppen]

Hehe

[+stephena]

I forgot to post this a while back. It's a 128 byte intro (demo) for the Atari 2600. It placed 2nd in the 128 byte competition at Outline 2012.

 

It doesn't work correctly in Stella, so you need to use MESS (with the 4k ROM) or a real machine (via say Harmony).

 

All 3 ROMs are working for me in Stella here. BTW, in the future if you find a ROM that doesn't work in Stella, I'd appreciate some feedback/bug reports on it before you release it.

[Keatah]

It isn't working correctly for me..

[+stephena]

Can you define "not working correctly?" Exactly what's not working correctly for you? I can't fix it unless I know what symptoms you're seeing.

[Keatah]

Of course, sorry. The image is in b/w. The youtube video is in color.

[+stephena]

Of course, sorry. The image is in b/w. The youtube video is in color.

 

That's because there's an odd # of scanlines, and in PAL mode with 'color-loss' enabled you get B/W. Press Control-L to toggle the 'color-loss' effect.

[Keatah]

More detail. It works correctly if I start it through the GUI. Color seems fine.

If I click on it in explorer and rely on .bin file assoction with stella to start it; it runs in b/w.

[Keatah]

Good

[+stephena]

More detail. It works correctly if I start it through the GUI. Color seems fine.

If I click on it in explorer and rely on .bin file assoction with stella to start it; it runs in b/w.

 

To me, that says that the settings file is different between launching it from Explorer vs. from the GUI. It seems that the 'color-loss' effect is turned on for the former, and off for the latter. Of course why that's happening is another issue ...

[Keatah]

Well yes that is exactly the "problem".. I like to keep stella's settings in a different directory other than %userdata% - and rely on the basedir.txt file to specify that directory. Everything works fine and it enables me to keep multiple configs at the ready.

 

If i start stella by relying on the association to *.bin, stella goes ahead and creates a new stella.ini %userdata%.. And that means a different config.

[Keatah]

Well no big deal I'm quite pleased with the way stuff works now. Been doing that for years.

[alex_79]

According to the README file in the archive posted by Tjoppen , the problem in Stella is speed.

If you run the rom in Stella and press the ALT-L key combination, it display "343 scanlines @ 50.00fps" while it should be about 45.5fps with that scanline count.

Also note that the demo never enables VSYNC nor VBLANK, and the screen actually rolls on a real TV. The rom doesn't have its own framerate / scanline count, because it never sends to the TV the signals to start a new frame. The actual framerate depends on the max number of scanlines the particular TV set you are using can display before retracing the electron beam.

Stella seems to allow a max of 343 scanlines before starting a new frame, but it doesn't set the right framerate in this case (while it does correctly in other roms with off-specs scanline counts as long as they enable VBLANK/VSYNC).

Edited October 18, 2012 by alex_79

[+stephena]

Thanks for the report. I'll look into it.

[Tjoppen]

Yep, alex_79 nailed it. I should add that the colour does work correctly on my TV set even though I'm not doing VSYNC.

 

If you manage to get it to play at the correct speed the audio may be a bit off. I suspect this because bit-banging PCM data without doing VSYNC doesn't work very well in Stella. Both xSqueeker (http://www.pouet.net/prod.php?which=58051) and Sound Coder (http://www.pouet.net/prod.php?which=59283) demonstrate this problem. But maybe this doesn't happen if using the normal sounds "as intended"..

[+stephena]

Yep, alex_79 nailed it. I should add that the colour does work correctly on my TV set even though I'm not doing VSYNC.

 

If you manage to get it to play at the correct speed the audio may be a bit off. I suspect this because bit-banging PCM data without doing VSYNC doesn't work very well in Stella. Both xSqueeker (http://www.pouet.net...php?which=58051) and Sound Coder (http://www.pouet.net...php?which=59283) demonstrate this problem. But maybe this doesn't happen if using the normal sounds "as intended"..

 

There are several issues here. I've fixed the incorrect framerate calculation; as specified above, it wasn't being done for out-of-spec scanline counts without VSYNC. The colour issue happens for two reasons. First, the maximum scanline count in Stella is 342 (ie, its virtual 'TV' can only handle that much). However, due to off-by-one error in a comparison, the scanline count was being set to 343. And since colour-loss is enabled by default for PAL ROMs, that odd # of scanlines was making the colours grayscale. So that is now fixed too; the scanline count is 342 in the maximum case.

 

Finally, if there is an issue with 'bit-banging PCM data', it could be because the current sound code isn't precisely cycle-accurate. A fix for this is coming in the next major release (3.8 ).

[+stephena]

I've tested both ROMs mentioned above (xSqueeker and Sound Coder), and they sound much better now after the fixes added to Stella. I don't have a working PAL system yet, so I can't absolutely confirm that it sounds the way it's supposed to ...

 

EDIT: Even Quadrun sounds better now, with no skipping in the 'quadrun, quadrun, quadrun' speech

[+stephena]

Stella 3.7.3 is now released, which includes the sound fixes mentioned above. More invasive sound changes will have to wait until the next major release.

[Godzilla]

loves 2600 demos. and 128 bytes! dang!

[Tjoppen]

Stella 3.7.3 is now released, which includes the sound fixes mentioned above. More invasive sound changes will have to wait until the next major release.

Ooh, nice. I'll have to check it out later. Great job, cheers!

[+stephena]

Unfortunately, a minor bug crept in that causes issues in other ROMs. Look for 3.7.4 soon ...

[Ed Fries]

Does this work with Harmony? It didn't for me (even the 4K version). Neither did other 128b and 256b tests I tried.