I think frantik is saying what I was gonna say. You could edit another rom first with the final 4 worlds first. And then stick that rom to the back of the newly expanded rom.

You could get the Crabs and Fighter Flies from the Mario Bros. ROM and the Hammer and Barrels from Donkey Kong, both NES versions.

~Ben (SMB2J-2Q)

frantik, your understanding of the expanded ROM's layout is correct. I didn't even think about the location of the CHR-ROM having changed, but now that you mention it, I can see how it would matter. The method you've proposed should be workable and fairly easy to impliment with the setup I currently have.

What I was actually wondering about was whether the editor would be able to make use of additional space for levels if such space was provided. Specifically, I was wondering what sort of control it allows over where in the ROM the levels are located and whether it has any limit on how much space it'll let you use up. It seems like there might be such restrictions to prevent you from overwriting other parts of the ROM and corrupting it.

I've also realized that my current code leads to the creation of a woefully inefficant IPS patch. Due to my simply having added a call to my mapper setup routine in the main intialization, the entire contents of the rest of the ROM where shifted down three bytes. At the time I didn't think this'd be an issue, but the IPS format has no provisions for insertions or deletions and only handles overwrites, leading to a (relatively) huge patch.

However, given the nature of ROM expansions, even if I corrected this particular issue, all of the ROM's contents past the first 16k will still be affected by the limitations of the IPS format. This basically leads to the patch containing a large portion of the ROM's contents. The only reason the patch isn't even larger is that large chunks of the expanded ROM are (currently) empty (containing zeros) and so can be compressed by IPS's RLE compression.

Perhaps it's nothing and I shouldn't worry about it, but it seems a little bit distressing. In particular, with over half of the original ROM's contents contained in the patch, it seems that the (supposed) legal distinction between ROMs and patches is considerably blurred (in cases like this). Not that I'm worried about legal action or anything, but it is an issue hackers who use ROM expansion should be aware of and consider the implications of.

I thought i t was gonna be more people, but it looks like it came down to just you two working on the hack. At least we'll get the level edits, if not the enemies, or other features. That's probably as much as we can hope for.

Anyhow yeah, I hope u guys figure out how to properly make a patch out of this. Cause I can imagine this site having a problem with hosting a patch that contains the original code and we don't want this patch getting lost on some geocities site or something. It should be hosted here. And good work on world 5.

Once I finish the level entry I will be able to contribute to the asm hacking more.. though it wouldn't hurt to have a dedicated asm hacker on board i suppose, especially someone who's actually added new enemies to SMB, if there is anybody around like that

sure, it's one of the patches in this zip, though i forget which patch.  I think it's the one which changes the first level around a bit as well.  http://betaworld.hp.infoseek.co.jp/ips/R_plants.zip

I tried out the expanded ROM and unfortunately it does look like the memory addresses are hardwired or something because only one more item was added to the level (after I moved the 'FD' terminator byte to the end of the added bytes that is).  thats kind of a bummer :\\

I agree it shouldn't be a big deal.. though one thing that might be an issue is the total number of levels.. the SMB engine allows for 34 levels total, which only leaves two levels which can be bonus rooms or whatever.  right now my lay outs have some bonus rooms which are on their own levels.  these will have to be consolidated i suspect, or we'll have to add in more rooms which hopefully won't be too hard.