+bhall408 Posted July 30, 2021 Share Posted July 30, 2021 Working on emulation, ran into this unusual case with Joust... MAME and Atari++ both have an issue where the game will load and run, but the screen will be all black. Atari800MacX in 5200 mode does not have this issue, nor does OpenEmu (also Mac). Looking at a debugger the hardware color registers will be 0, and if you force them to non-zero, you'll get an image. To make things even more exciting, if you wait long enough and the system attract mode kicks in, you WILL get a non-blank screen. (see attached shot) I'm wondering what Joust could possibly be doing differently (that would screw up GTIA emulator) when all the other games so far are running fine... I'll be poring over Mapping the Atari and De Re for inspiration Any ideas? Quote Link to comment Share on other sites More sharing options...
Rybags Posted July 31, 2021 Share Posted July 31, 2021 On the title screen there's colour changes onscreen as well as the colours being stored during VBlank. If the colours are zeroed then there's probably some sort of bug in the emulator assiming the game Rom is OK. Both title screen and in game uses DLIs which do the colour changes though ingame I think it's only PMG objects that have the DLI changes. If the emulator has decent debugging then you'd want to see what values are in the colour shadow registers as well as the ones the game uses midscreen. e,g. the title screen uses $C06 for the COLPF1 change by DLI, $C00 for COLPF2. COLPF3 is cycled on the title screen during VBlank for the animated title border. Quote Link to comment Share on other sites More sharing options...
phaeron Posted July 31, 2021 Share Posted July 31, 2021 This happens if you emulate a fictional PAL 5200, since the game checks the PAL register and seems to have unfinished adaptation code. 3 Quote Link to comment Share on other sites More sharing options...
+bhall408 Posted July 31, 2021 Author Share Posted July 31, 2021 11 hours ago, phaeron said: This happens if you emulate a fictional PAL 5200, since the game checks the PAL register and seems to have unfinished adaptation code. This sounds likely/plausible as the reason, we'll give it a try! Quote Link to comment Share on other sites More sharing options...
thorfdbg Posted July 31, 2021 Share Posted July 31, 2021 You need to set the cart type to 32KEE16 (incompletely mapped 32K cartridge) and in the speed menu the system to "NTSC", then it will work in atari++ just fine. 2 Quote Link to comment Share on other sites More sharing options...
+bhall408 Posted July 31, 2021 Author Share Posted July 31, 2021 50 minutes ago, thorfdbg said: You need to set the cart type to 32KEE16 (incompletely mapped 32K cartridge) and in the speed menu the system to "NTSC", then it will work in atari++ just fine. OK, Andy found it - woot! We'd already been forcing the cart mapping and GTIA to NTSC, but there were other flags... So we found the full suite of flags needs to be: "-VideoMode", theNTSCPAL, "-PokeyTimeBase", theNTSCPAL, "-ANTICVideoMode", theNTSCPAL, "-GTIAVideoMode", theNTSCPAL, "-TapeTimeBase", theNTSCPAL, // For later on and then we get this... 1 Quote Link to comment Share on other sites More sharing options...
+bhall408 Posted July 31, 2021 Author Share Posted July 31, 2021 Next up (in terms of bank switching), we need to add the mapper that Berks 4 is using... 1 Quote Link to comment Share on other sites More sharing options...
thorfdbg Posted July 31, 2021 Share Posted July 31, 2021 As long as you set GTIA/ANTIC/Paula to "Auto", the only switch needed is that in the "speed" menu. "Auto" means that the chips take their settings from the speed menu. Quote Link to comment Share on other sites More sharing options...
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