Updating old mame roms
Imagine you have a complete MAME ROM set (for example v0.62) and you want to send to a friend the update CDs required to update his v0.60 ROM set.
One possible way to do this is sending him the full set, but there is another way in which you would only be sending him the files required to perform the update (in his v0.60 ROM set he has almost everything required for v0.62, so no need to send him the full set).
Another possible error is the renaming of some of the ROMs inside a BIOS file.
We must again manually perform the update by changing the name to the correct one (this has happened with some of the ROMs in the BIOS file).
A good example of the huge space saving that merging can bring is the game Dungeons & Dragons: Shadow Over Mystara.
In MAME v0.59, this game has 6 sets (this number can vary with future versions).
In these files is information about ROMs contained in particular sets: names, merging information, which is the main set and which are clones, CRC for each ROM, etc.
To perform the update itself, just go back to section 4 in this guide.Continuing with our example, we can say that the two 1941 sets must be named 1941(World) and 1941(Japan).In the Split / Not Merged mode, there is an independent file for each ROM set, each containing all the required ROMs for the set.When we update our ROM set, this new file wont be automatically copied to the ROMs folder so if after the update we scan our ROM set, the Scanner would report that BIOS file as missing.To solve this, we must copy the file in the ROMs folder (the most recent example of this problem is the update from MAME v0.61 to v0.62, where the new BIOS file has been included).