Found this at AssemblerGames.com. This is a hex edit for DOA3's Default.xbe file to enable a 21:9 ultra widescreen aspect ratio.
Open Default.xbe in a hex editor. Find the value "3F 0000103F" and replace it with "3F 0000D83E"
This patch is only for DOA3.1/DOA3++ and DOA3.2. The "3F 0000103F" value does not exist in DOA3.0's default.xbe, so I'm unsure how you would make the edit for that version, not that anyone wants to play it anyway.
Open Default.xbe in a hex editor. Find the value "3F 0000103F" and replace it with "3F 0000D83E"
This patch is only for DOA3.1/DOA3++ and DOA3.2. The "3F 0000103F" value does not exist in DOA3.0's default.xbe, so I'm unsure how you would make the edit for that version, not that anyone wants to play it anyway.