MAMEGPL-2.0-or-later. The driver, device and emulator-core sources this port was transcribed from, and the reference its lockstep oracle is measured against.
Scott Tunstall — annotated 6809 disassemblyThe full annotated listing of the Solid Blue ROMs: memory map, task OS, every enemy AI, the wave tables, scoring and collision. The ground truth this port's game logic is transcribed from.
Christian GingrasHand-annotated the game by reading 512 pages of listing in 1984–86 and found roughly seven bugs, including the fatal shot-in-the-corner crash that Larry DeMar's 1987 patch fixes.
Chris LomontAn independent complete disassembly and assembler that rebuilds byte-exact ROMs across five revisions.
Sean RiddleWilliams hardware documentation, and hosts the disassembly above.