Trebor Posted January 20, 2017 Share Posted January 20, 2017 Absolute's Title Match Pro Wresting - Significant scanline corruption when swinging opponent in the corner under Stella 5.0.0-Pre4. Slight scanline corruption when swinging opponent in the corner under Stella 4.7.3. No scanline corruption when swinging opponent in corner under real hardware. 2 Quote Link to comment Share on other sites More sharing options...
Keatah Posted January 20, 2017 Share Posted January 20, 2017 (edited) Time Pilot.bin looks different, note the top white line in 4.7.3. Missing in Pre-4. Edited January 20, 2017 by Keatah Quote Link to comment Share on other sites More sharing options...
+stephena Posted January 21, 2017 Author Share Posted January 21, 2017 This is simply because the image is placed a little too high in the window (ystart is off). When I move the image down, the white line can be seen. This will potentially be fixed with further ystart work. Quote Link to comment Share on other sites More sharing options...
Trebor Posted January 21, 2017 Share Posted January 21, 2017 Issue which occurs under Stella 5.0.0-pre4, but does not occur under real hardware or Stella 4.7.3: Atari's Warlords - Upper Right/Blue Warlord missing 1/2 (right-half) of its bottommost representation piece: 3 Quote Link to comment Share on other sites More sharing options...
Keatah Posted January 21, 2017 Share Posted January 21, 2017 (edited) I do not know if this is an emulation problem or a game problem. Look at the mountain terrain and note how it changes as you move the ship left or right. There's a point where it shows some "distortion" too. Early 2.x versions of Stella and Z26 show the same thing. Edited January 21, 2017 by Keatah Quote Link to comment Share on other sites More sharing options...
Keatah Posted January 21, 2017 Share Posted January 21, 2017 (edited) I've come across about 15-20 demoscene demos that seem to work correctly in 4.7.3 and 3.9.3 equally well, but fail significantly in pre4. Various fail modes can be described as obvious graphic corruption, incorrect bit-map decoding, scrambled logo, scratchy or incorrect sound, ghosting where there should be smooth clear animation, random plasma lines where there should be solid color, bouncy or jittery background. One demo has a slowdown to 3/4th speed. And other similar types of fails. If you all care about such things I'll make a zip file and you can see for yourself. Edited January 21, 2017 by Keatah Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted January 21, 2017 Share Posted January 21, 2017 Yes, please. If possible, with a brief description of the errors you noticed. Or just post them here, one by one. Since most demos were developed without testing on real hardware, I wouldn't be surprised if some of them fail due to better emulation. 1 Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted January 21, 2017 Share Posted January 21, 2017 I do not know if this is an emulation problem or a game problem. Look at the mountain terrain and note how it changes as you move the ship left or right. There's a point where it shows some "distortion" too. Early 2.x versions of Stella and Z26 show the same thing.That's how Buck Rogers looks on read hardware too. So just bad game programming here. 2 Quote Link to comment Share on other sites More sharing options...
DirtyHairy Posted January 21, 2017 Share Posted January 21, 2017 (edited) If you all care about such things I'll make a zip file and you can see for yourself. Definitely, we are interested in all deviations between Stella 4, the new core and / or real hardware. If you like, you can also create a Github account and report issues there directly. The second Thomas' statement: we've already encountered several demos that fail with the new core just as they fail on real hardware Generally speaking, I would be surprised if there are any serious issues left in the core --- the current setup already is highly constrained by the ROMs that work OK. The issues you and Trebor have reported so far are related to a few missing delays on which I haven't had any reliably data until now and the behavior of the chip in edge cases that are still unconstrained (mainly NUSIZ during sprite draw). Edited January 21, 2017 by DirtyHairy 1 Quote Link to comment Share on other sites More sharing options...
Trebor Posted January 21, 2017 Share Posted January 21, 2017 Atari's RealSports Boxing - Significant scanline corruption when standing in the lower rightside corner of the ring under Stella 5.0.0-Pre4. Slight scanline corruption when standing in the lower rightside corner of the ring under Stella 4.7.3. No scanline corruption when standing in the lower rightside corner of the ring under real hardware. Note: Appears to be same issue as seen under Absolute's Title Match Pro Wrestling. 1 Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted January 21, 2017 Share Posted January 21, 2017 Note: Appears to be same issue as seen under Absolute's Title Match Pro Wrestling.Yup. 1 Quote Link to comment Share on other sites More sharing options...
Trebor Posted January 21, 2017 Share Posted January 21, 2017 Different type of problem: Atari's RealSports Tennis - The attached binary plays perfectly, including displays properly, utilizing a Harmony Cart with my NTSC 4-switch Woody on my NTSC CRT. The same binary is recognized under Stella 4.7.3 and Stella 5.0.0-Pre4 as "(PAL) [a2]". If the game properties (Options --> Game Properties --> "Display" Tab) is changed from Auto-Detect to NTSC, it does not display properly. RealSports Tennis (1983) (Atari).bin Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted January 21, 2017 Share Posted January 21, 2017 The game is PAL, so switch to either PAL50 or NTSC50. With NTSC(60), Stella interrupts each frame early (because NTSC60 can't display 312 scanlines) and starts a new frame. Short after, the code starts a new frame again. That's causing the problems. Quote Link to comment Share on other sites More sharing options...
Trebor Posted January 21, 2017 Share Posted January 21, 2017 The game is PAL, so switch to either PAL50 or NTSC50. How does the same ROM image run under the Harmony cart (With correct colors - properly centered) with my NTSC console and NTSC CRT? *EDIT: Colors are off, but the image is centered...Interesting. Looks like it is indeed PAL; wonder what other PAL region games can run under the NTSC console with Harmony cart Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted January 21, 2017 Share Posted January 21, 2017 It doesn't depend on the Harmony cart or console. Its your TV which must support PAL 50Hz frequency. 1 Quote Link to comment Share on other sites More sharing options...
Keatah Posted January 21, 2017 Share Posted January 21, 2017 Remember I can only test in emulation. 3.9.3 and 4.7.3.. The demos look like they are supposed to in those versions. This core demo fails all over. There's "plasma lines" where there should be solid fills. And the "wavy road" portion runs slower and jitters. core demo.zip Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted January 21, 2017 Share Posted January 21, 2017 (edited) I have run them side by side in both emulators and couldn't see any problems. Can you post a few screenshots? Edited January 21, 2017 by Thomas Jentzsch Quote Link to comment Share on other sites More sharing options...
alex_79 Posted January 21, 2017 Share Posted January 21, 2017 Remember I can only test in emulation. 3.9.3 and 4.7.3.. The demos look like they are supposed to in those versions. This core demo fails all over. There's "plasma lines" where there should be solid fills. And the "wavy road" portion runs slower and jitters. Maybe you have the "Drive unused TIA pins randomly on read/peek" option selected in the debugger? If so deselect it, as it should be only used during development. 4 Quote Link to comment Share on other sites More sharing options...
Keatah Posted January 21, 2017 Share Posted January 21, 2017 Yes it was checked. Not sure how it got that way. Unche The 10 or so demos I were going to report seem to be working fine now. Noise & scratch sound, static/distorted graphics, stray plasma lines and scrambled graphics, and other funkiness all where it should be! There are 2 other demos to be checked. The Coke Zero demo. The bottom grey text bar moves up and down a bit in the first 10 seconds. Then it seems steady and ok for the rest of the show. No other issues. Maybe its related to post #78. Presk/Flush demo. Not sure what the title page is supposed to look like. The stray horizontal line below the "F" supposed to be there? And the white line at the top of the Atari logo, that supposed to be there? Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted January 22, 2017 Share Posted January 22, 2017 (edited) Coke Zero is doing some trickery with disabling vertical blank. Which is very unusual, even for demos. Set YStart to 27 and Height to 213 and the problem is gone. Presk is emulated correctly. Edited January 22, 2017 by Thomas Jentzsch 1 Quote Link to comment Share on other sites More sharing options...
+SpiceWare Posted January 29, 2017 Share Posted January 29, 2017 Crispy posted this today, could be useful - Cosmic Ark Star Field Revisited Quote Link to comment Share on other sites More sharing options...
DirtyHairy Posted January 29, 2017 Share Posted January 29, 2017 (edited) Crispy posted this today, could be useful - Cosmic Ark Star Field Revisited Thanks alot for the reference --- very usefuly indeed! I have to sit down and wrap my head around this in detail, but after a superficial read, this seems to confirm what I had already suspected: the effect is an interference pattern induced by slight differences between the extra clock pulses and the regular pixel clock. While the emulation is not detailed enough to describe this effect from first principles, this will certainly help in improving the effective description. Edited January 29, 2017 by DirtyHairy Quote Link to comment Share on other sites More sharing options...
Trebor Posted February 2, 2017 Share Posted February 2, 2017 Derailing thread slightly to wish Stephen a Happy Birthday! Thank you for 'keeping the faith' with Stella. Ditto to the rest of you guys regarding Stella and moving forward with improving emulation. Stella is the gold standard for Atari 2600 emulation. Glad that bar as been set so high and continues to rise. 6 Quote Link to comment Share on other sites More sharing options...
+stephena Posted February 2, 2017 Author Share Posted February 2, 2017 Thanks for that, and glad that you noticed. I'm 43 now, and I started working on Stella just after graduating from University (late 2000 or so). So that's 16 years at this point. Roughly the same amount of time I've been working professionally. Where does the time go? 2 Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted February 2, 2017 Share Posted February 2, 2017 I'm 43 now... Kid! 1 Quote Link to comment Share on other sites More sharing options...
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