MAMEWorld Forums - EmuChat - Re: Several bugs with (EUR) Roms with MESS

> 2) It looks like EUR versions of Super Mario Bros games for NES are way too fast. It
> runs like 1.5 times the normal speed. It looks like those are the few european games
> with clock speed problems. That's strange...

Officially, there is only one PAL version of Super Mario Bros. (circa 1990), which was optimised to run about 20% faster (1.2x speed) to match the NTSC version. However, the game was first released in PAL regions in 1987 using the Japanese NTSC game chips, and due to the clock speed and frame rate differences between NTSC and PAL, this version runs slower and the music is flat (one half-note lower), as with many early titles - Mario Bros., Pinball, Excitebike to name a few.

NTSC game on PAL system = 50/60 = 83.33% speed = 16.67% slower
PAL game on NTSC system = 60/50 = 120.0% speed = 20.00% faster

If the pitch of the music/sound effects is tied to the console's clock speed as well (as with the NES and Sega Master System), then the music will also be the same percentage slower/faster (roughly one half-note down/flat for an NTSC game on PAL and one half-note up/sharp for a PAL game on NTSC).