mhoes wrote: ↑
Sat Aug 15, 2020 12:35 pm
A full 'rom set' is the collection of all the roms that MAME currently supports. But if you don't want to play all of them, then you will not need them all. For example, if you do not plan to play pacman, than obviously you do not need to obtain the roms for pacman, and only the roms for the games you plan to play. What makes this a bit tricky is that it is not always obvious which roms are for what game, so that will require a little googling.
Also, please read the page that Tafoid already linked to for you: https://docs.mamedev.org/usingmame/aboutromsets.html
And there you'll see the following text: "For arcade games, a ROM image or file is a copy of all of the data inside a given chip on the arcade motherboard. For most consoles and handhelds, the individual chips are frequently (but not always) merged into a single file. As arcade machines are much more complicated in their design, you'll typically need the data from a number of different chips on the board. Grouping all of the files from Puckman together will get you a ROM set of Puckman. An example ROM image would be the file pm1_prg1.6e stored in the Puckman ROM set."
mhoes, it seems you and our documentation might disagree on the definition of "ROM set".
The point is, a single arcade game is typically comprised of a good dozen ROM chips, or ROMs. Each ROM is dumped by a ROM programmer individually. So you wouldn't describe a single arcade game as "a ROM". Compared to, say, a console game cartridge, which were often internally a single ROM chip or two ROM chips, but dumping game cartridges were often done through the connector back in the day, resulting in a single "cartridge dump".
All that said, unfortunately it's become common that the gamer community often calls a single arcade game as emulated by MAME "a ROM"...