After Burner III (Sega CD)

After Burner III
Developer: CRI Publishers: CRI (JP), Sega (US/EU) Platform: Sega CD Released in JP: December 18, 1992 Released in US: 1993 Released in EU: 1993 This game has debugging material. This game has a hidden level select.

To do: Regional Differences.

Debug Options

Japan	International

A debug menu, which differs slightly between versions, can be found on file mdl01_m.bin. This file is loaded into the Main CPU RAM at offset 0xff0000.

Each title screen menu has an associated subroutine, including the debug menu (addresses taken from the Japanese version):

00ff003e 4e bb 00 04     jsr        (0xff0044,PC,D0w*0x1)
00ff0042 4e 75           rts
00ff0044 60 00 00 c6     bra.w      LAB_00ff010c
00ff0048 60 00 05 88     bra.w      LAB_00ff05d2
00ff004c 60 00 09 5e     bra.w      LAB_00ff09ac
00ff0050 60 00 14 de     bra.w      LAB_00ff1530
00ff0054 60 00 13 60     bra.w      LAB_00ff13b6
00ff0058 60 00 07 84     bra.w      LAB_00ff07de
00ff005c 60 00 16 48     bra.w      LAB_00ff16a6 ; debug options
00ff0060 60 00 1b 06     bra.w      LAB_00ff1b68

The subroutine index for the title screen options menu is set at 0xff079c:

00ff079c 11 fc 00        move.b     #0x8,(DAT_fffff703).w
         08 f7 03
00ff07a2 4e 75           rts

We can replace that index with value 0x18 to load the debug menu, by applying to the CD's data track one of the following patches:

Japan	International
81adf = 18	82409 = 18

(Source: Original TCRF research)