New SCUMM File Format

(From Monkey Island 2 till CMI)

With Monkey Island 2 a lot of changes occured. MI2 was the first game to use the iMUSE technology. Also, while the Amiga had been the development platform for the games until now, the games were now developed on PC and ported to Amiga and other platforms afterwards. And, just as important to SCUMM explorers, the file format changed substantially from the previous format. A block would now look more like the original IFF format:

"B" "O" "X" "D" 00 00 00 0A 00 01

The name is still there, the size is still there, but the ordering of them has been changed: The name is now four characters long, rather than two, the size is now in big endian, rather than little endian, and the size comes after the name, rather than before. After these 8 bytes, the data comes.

Other than that, the same rules as for the old format apply. The format is still hierarchal, subblocks can be contained within other blocks. The scheme of the new standard block thus looks like this:

sName	4*char	Block name.
dwSize	dword	Block size (BE).
data	(dwSize-8)*byte	Block data.

So, the size still includes in it the 8 bytes starting off the block - mostly... Because the new format proved to be much less standardized, probably due to several different developers working on it. Thus, blocks such as the new MIDI blocks (ADL, ROL, GMD etc.) don't include the initial 8 bytes in the size. Other blocks have the size a byte or two off etc. And blocks using compression often have a decompressed size given, rather than the size they actually have inside the resource file. A complete list of the found size formats for all types of SCUMM Revisited-openable files can be found here.