Many Neo-Geo games have debug menus and development tools lurking in their code, waiting to be discovered. Some are as easy as messing with the Debug DIPs, while others require more work.
Twinkle Star Sprites
If ROM address 0x0000FF (0x1000FE in an un-byteswapped "224-p1.p1") is set to
0xDB, debugging features will be available.
The main debug menu, "--- PROGRAM MENU ---", is accessed by holding down Player 2's A, B, C, and D buttons on boot.
Select Button Menu
Another debug menu is available by pressing Player 1 Select at any time.
The Last Blade
The Last Blade has a tool menu; more research is needed. (This was discovered on 2ch. Is this the same menu that you get with debug dip 2-4?)
In "234-p1.bin" (un-byteswapped?) make these changes:
- 0x5F5F4: 0xAA → 0x40
- 0x5F5F5: 0xF3 → 0xAF
Viewpoint has a special test/debug type menu. This was discovered by Razoola on the CD system while working on the Universe Bios but also works on the MVS/AES versions of the game.
In "051-p1" make this change:
- 0x3FFFF: 0x7F → 0xFF
When game is running press START+SELECT at the same time, the game will pause and you will see the word 'PAUSE' in the top right corner. Pull the joystick DOWN and the new menu will appear.
- Neo Bomberman's debug menu and "DEBUGING(sic) MONITOR"
- Other games are likely to have something lurking in them...