Difference between revisions of "Common Emulator Development Issues"

Revision as of 18:34, 31 May 2023

ROMs That Can Cause Issues

• Choplifter. If the line between the horizon isn't in the correct place, or moves, it means that DMA cycle penalties or timing aren't accurate.
• Choplifter. If there's a glitch zone high in the sky, it means your TIA address space doesn't emulate a floating bus correctly.
• One On One. If the player can't advance past the option menu with a button press, it means the RIOT 2-button implementation is incomplete.
• Worm! If the game can't be started at all, it means that the RIOT 2-button implementation is incompete.
• Xenophobe. If the bottom row of the titlescreen graphic is the incorrect color, it means that DMA cycle penalties or timing aren't accurate.
• Xenophobe. If all of the main action screen glitches periodically, it means that DMA cycle penalties or timing aren't accurate.
• Ninja Golf. If the player number selection screen has squished graphics (displaying 160A graphics at 160B) then you need to account for non-zero DLL terminators. Maria ignores bits 7 and 5, so your terminator check should be for "!(value & 0x5F)".
• Crossbow. If all graphics appear garbled/in wrong mode then you need to account for non-zero DLL terminators. Maria ignores bits 7 and 5, so your terminator check should be for "!(value & 0x5F)".
• Planet Smashers. If the background starfield is replaced by glitched graphics, you aren't checking the entire 8000-BFFF range for the bankswitch hotspot. This game uses the BFFF hotspot.
• Alien Brigade. Corruption in the main screen can be caused by missing or incorrect DMA cycle penalties, whenever lots of objects are displayed in this game.
• Summer Games. If the Platform Diving event has a flickering line between the stands and pool deck, it means that DMA cycle penalties or timing aren't accurate.
• Ace Of Aces. If the top line of sky bounces around, it means that DMA cycle penalties or timing aren't accurate.
• Karateka. If during the second enemy stage, there is flickering in the bottom right area and/or the power meter, it means that DMA cycle penalties or timing aren't accurate.

ROMs That May Look Buggy But Aren't

• Tower Toppler. If the game keeps skipping levels, this is part of a level-skip feature that's activated by the difficulty switch position.
• Xenophobe. During the play player one level completion stats the last line of the ship is displayed in 320A instead of 160A like the rest of the ship. The result of this is last line appears as a series of alternating pixels.
• Commando. If the game doesn't play Pokey music, you have a dump with a bad A78 header.