Help need:How to edit some levels-bugs in original SMB?

[SysDataSoft]

How to edit some levels-bugs in original SMB? example: world -1 or world 9-1.  

[KingMike]

Use a level editor and edit them? We don't know, you need to be more specific where the problem is.

Also, 9-1 isn't a real world in the original SMB it's a glitch level made by reading other ROM data, so you can't edit those without, probably, corrupting the game.

[SMB2J-2Q]

How to edit some levels-bugs in original SMB? example: world -1 or world 9-1.  

Please try to be more specific as to what bugs/glitches you're referring to.

~Ben

[JP32]

Watch this to learn why there are bugged levels in the first place:
https://www.youtube.com/watch?v=B8o_VpY9scs
and then
https://www.youtube.com/watch?v=1ysdUajrhL8

But to answer your question, blank-1 is 2-2 and 9-1 is 6-2 so you need to edit the original levels to edit the bugged levels, now if you want to make them completely original levels then thats different and considering your post beyond your skillset.