Hacked the System Card to display BIOS execution

[ccovell]

Hi, folks.  Just to see what CD games did when they booted, I hacked my own code into the PC-Engine CD card to report (both on-screen and via serial port) which BIOS calls get executed on real hardware. It's a tad glitchy, probably because I'm stealing CPU time, but the results are kinda cool.

Perhaps an emulator / watchpoints / lua script could do a better job, but oh, well.

Here's what I captured from Pomping World:
E06F 25 EX_SCRMOD 1E 20 00
E06C 24 EX_DOTMOD 00
E0A2 36 EX_SATCLR
E006 02 CD_BASE   0024 8200 0E82
E009 03 CD_READ   B008 8000 0020 0116
E009 03 CD_READ   0008 8000 0020 0116
E009 03 CD_READ   0008 8000 0020 0116
E009 03 CD_READ   0008 8000 0020 0116
E009 03 CD_READ   0008 8000 0020 0116
E009 03 CD_READ   0008 8000 0000 0116
E05D 1F EX_SETVEC 40 D5 01
E063 21 EX_JOYSNS
E033 11 AD_TRANS  0020 0000 0400 00C6
E009 03 CD_READ   0004 C000 0500 010A
E0E4 4C EX_COLCMD
E063 21 EX_JOYSNS
E0A2 36 EX_SATCLR
E060 20 EX_GETFNT 8358 9D00 0000
E060 20 EX_GETFNT 835E 9D20 0000
E060 20 EX_GETFNT 815B 9D40 0000
E060 20 EX_GETFNT 8367 9D60 0000
E060 20 EX_GETFNT 82B7 9D80 0000
E060 20 EX_GETFNT 82E9 9DA0 0000
E060 20 EX_GETFNT 926E 9DC0 0000
E060 20 EX_GETFNT 935F 9DE0 0000
E060 20 EX_GETFNT 82F0 9E00 0000
E060 20 EX_GETFNT 8C88 9E20 0000
E060 20 EX_GETFNT 82DF 9E40 0000
E060 20 EX_GETFNT 82C4 9E60 0000
E060 20 EX_GETFNT 89BA 9E80 0000
E060 20 EX_GETFNT 82B3 9EA0 0000
E060 20 EX_GETFNT 82A2 9EC0 0000
E060 20 EX_GETFNT 8142 9EE0 0000
E060 20 EX_GETFNT 8140 9F00 0000
E060 20 EX_GETFNT 8140 9F20 0000
E060 20 EX_GETFNT 8140 9F40 0000
E060 20 EX_GETFNT 8140 9F60 0000
E060 20 EX_GETFNT FE79 9F80 0000
E063 21 EX_JOYSNS

[NightWolve]

Would be cool if it can help with debugging, things like tracking down the game's text decompression code, the print routine, custom font tiles, etc.