Foebane Posted February 3, 2016 Share Posted February 3, 2016 Most of the A8 Demoscene prods I have work fine on Altirra, except this one doesn't fully do so: http://www.pouet.net/prod.php?which=9748 It's a three-disk demo that always lingers on the first part of the second disk, namely the grey box floating around the crowned skull pic. I think it's something to do with SIO, but does anyone have experience in this sort of thing and getting Demos to run on Altirra? I have the latest version. Quote Link to comment Share on other sites More sharing options...
JD6502 Posted February 3, 2016 Share Posted February 3, 2016 I'm no expert on this stuff, but I tried looking at the disk contents using a couple of different tools and the ATR looks to be unreadable. It may be corrupted. Since Altirra is not the only program that has trouble reading it, it's probably not an emulation problem. Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted February 3, 2016 Share Posted February 3, 2016 It's said that the demo loads itself using custom SIO code which completely bypasses the OS, so its unlikely the ATR will contain any kind of recognizable file system. The second disk does indeed loiter on said skull segment, and Altirra's drive 1 activity indicator is stuck on. I don't know if this is significant of Pokey serial input ready status not being cleared. Quote Link to comment Share on other sites More sharing options...
+CharlieChaplin Posted February 3, 2016 Share Posted February 3, 2016 (edited) Have you downloaded this version: http://seban.slight.pl/pouet/overmind.zip Edited February 3, 2016 by CharlieChaplin Quote Link to comment Share on other sites More sharing options...
Mclaneinc Posted February 3, 2016 Share Posted February 3, 2016 Works ok here... If its a custom SIO always best to select accurate SIO, here it went to a square pattern segment... Also make sure you have the right Firmware selected, by default Altiira selects by auto so I always set it to pick XL version 2, if by accident its picking Altirra OS you may get oddities with custom stuff. Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted February 3, 2016 Share Posted February 3, 2016 (edited) That's a good point. I turned off Ultimate 1MB when testing, and without a care to which OS ROM took its place. Edited February 3, 2016 by flashjazzcat Quote Link to comment Share on other sites More sharing options...
JD6502 Posted February 3, 2016 Share Posted February 3, 2016 My mistake, I should have taken more time looking at it before chiming in. I ran through side one and two using Altirra 2.5, XL LLE and side two ran fine. Side two won't boot on it's own. I'll try running both disks under 2.7. Quote Link to comment Share on other sites More sharing options...
JD6502 Posted February 3, 2016 Share Posted February 3, 2016 It runs fine on Altirra 2.7 under ATOS. Quote Link to comment Share on other sites More sharing options...
Foebane Posted February 3, 2016 Author Share Posted February 3, 2016 Have you downloaded this version: http://seban.slight.pl/pouet/overmind.zip Yeah, I tried that - same problem. I assume those files are identical to the download link on the main part? Quote Link to comment Share on other sites More sharing options...
Foebane Posted February 4, 2016 Author Share Posted February 4, 2016 So what settings do I need in Altirra (the latest)? Quote Link to comment Share on other sites More sharing options...
Foebane Posted February 4, 2016 Author Share Posted February 4, 2016 I finally got it working, and it wasn't a corrupted set of ATRs. Simply autodetecting the OS and enabling the drive with accurate sector timing made it work properly - those were things I hadn't tried before. Thank you all for this advice, should help with other problem ATRs too! Quote Link to comment Share on other sites More sharing options...
phaeron Posted February 4, 2016 Share Posted February 4, 2016 I have an idea of what's causing this and can address it in the emulator, but in the meantime, try using PAL instead of NTSC. If I'm right, the problem manifests when the part of the VBI that does command I/O gets pushed late, which is more likely to occur in NTSC. The demo is fairly well behaved in NTSC but does have a couple of portions that glitch occasionally due to apparent VBI overruns. You'll also want to turn off D: burst I/O, but presumably that's already off as you wouldn't have even been able to boot with it on. Quote Link to comment Share on other sites More sharing options...
Heaven/TQA Posted February 4, 2016 Share Posted February 4, 2016 yup... those were times... nowadays better to put a starting screen with Altirra settings... (like "best viewed with..."). and there not many NTSC demos so if I would try demos I always would set Altirra to PAL at least and if its an ATR I would set it to accurate SIO. Quote Link to comment Share on other sites More sharing options...
Foebane Posted February 4, 2016 Author Share Posted February 4, 2016 I have an idea of what's causing this and can address it in the emulator, but in the meantime, try using PAL instead of NTSC. If I'm right, the problem manifests when the part of the VBI that does command I/O gets pushed late, which is more likely to occur in NTSC. The demo is fairly well behaved in NTSC but does have a couple of portions that glitch occasionally due to apparent VBI overruns. You'll also want to turn off D: burst I/O, but presumably that's already off as you wouldn't have even been able to boot with it on. I use PAL for everything I emulate, as I've always been a UK resident, and it seems PAL is dominant in the Demoscene. Quote Link to comment Share on other sites More sharing options...
Mclaneinc Posted February 5, 2016 Share Posted February 5, 2016 (edited) Demo's are great for emulation exactness, they more than any other genre help make an emulated machine more accurate because of how demo coders bang the metal and do oh so naughty things which would only work on either a real machine or an emulator that is at the top of its game / demo (obviously this does not 100% apply if a demo / game is written solely on an emulator unless the emulator is running totally as a real machine). I watched over a period of time one guy test almost every demo on the Amiga emulator WinUAE and the guy was at times getting nigh on rude to the emulator author so I said so to the tester only for the emu author to say "its ok, the emulation quality has never been this good after he's found all these bugs". Hence getting demo's to work can be more fiddly but its worth it all around in the end for all concerned... Edited February 5, 2016 by Mclaneinc Quote Link to comment Share on other sites More sharing options...
Foebane Posted February 5, 2016 Author Share Posted February 5, 2016 I watched over a period of time one guy test almost every demo on the Amiga emulator WinUAE and the guy was at times getting nigh on rude to the emulator author so I said so to the tester only for the emu author to say "its ok, the emulation quality has never been this good after he's found all these bugs". You sure that wasn't me? I've asked Toni why some demos won't run on WinUAE, and he's either given me various tips or I've submitted logs to him to help him track down problems. In either case we got those demos to run eventually. Quote Link to comment Share on other sites More sharing options...
Mclaneinc Posted February 5, 2016 Share Posted February 5, 2016 (edited) You sure that wasn't me? I've asked Toni why some demos won't run on WinUAE, and he's either given me various tips or I've submitted logs to him to help him track down problems. In either case we got those demos to run eventually. No, deffo not you in this case, its a guy called Amillio or like that, I saw your posts on there as well. The guy in question was demanding to get a greeting in the emulator initially which since all of us like yourself submit bugs seemed a bit much but the guy had tested thousands of demo's which at that point I wasn't aware of and had spent so much of his time doing it he deserved a bloody medal But yeah, demos cause the most problems but ultimately find the very few bits Phaeron (and Toni) had missed or not emulated although getting the configuration right is also an issue, custom OS's odd non real life memory settings, timing / video format and corrupt files are just as much of a pain A bit unrelated but the initial computers etc were pretty much open to devs doing what they liked with from what I know very few guidelines of what NOT to do like with the 8bit to not directly use certain locations but to use the shadow locations in case an updated OS changed the main location. But as far as I know Atari never actually checked what people were doing as over machine creators also didn't check stuff, it was only with the consoles that people like Nintendo screened the carts so certain locations were not abused. The interesting fact or myth is that I heard there was a location Sega actually only allowed the Sonic team to use on the MD, I always meant to ask Steve Snake (author of Fusion a brilliant all things Sega 8 bit emulator and game dev for various titles like NBA Jam) if the story was true. At one point I made learnt carpentary and made pine furniture and he was a customer in Walthamstow, East London, saw all his dev kit and stuff, nice guy... The round about point being that emulator authors of the older computers have so much to check for in what would be classed poor coding Edited February 5, 2016 by Mclaneinc Quote Link to comment Share on other sites More sharing options...
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