I hate to waste a thread with this, since its such a minor question, (and knowing me I probably won't finish), but could someone explain the SMB1 level format to me (not the NES, SMAS in case its different and not obvious...). I was screwing around in Java making a very primitive stage editor in Java (all it can do is move the first block in 1-1 up and down, as well as change it's type), so I wanted to know if there's any odd quirks that I need to know about before I continue (the only one that comes to mind is that weird bug/feature with the original engine where if there's too many objects on screen, most of them delete themselves). I know this probably isn't the best game to start modding, but there seemed to be a lot of interest for this game, and I didn't want to waste my time making an alternative editor for something like SMW which already would have a far better editor (well, that, and I couldn't figure out SML2's level format...).
So yeah, for those that hate huge blocks of text, I'm making a SMAS level editor in Java that probably will:
1)Never get finished
2)Never get released
3)Have a terrible UI
...and I'd like to know anything odd or special about the SMB1 level format.