
Originally Posted by
FatTrucker
Generally speaking roms for older systems will be a single file commonly ending in .rom .bin .smc(snes) .sms(Master system) .nes .gba(gameboy advance) or.sg and .sc for the sg1000 etc. There are variances from system to system but they will generally be a single file in one of these common formats.
Systems that use multi-part roms like mame usually have all the roms contained in a single zip file for each game which has to remain zipped and be put into the rom folder. This includes non CD Neogeo games.
CD based systems like the Playstation, and Sega Saturn use disk images. These will generally be in the form of either a single .iso file or a .cue and .bin file. Dependent on where you source them from, some of these will come as a multi-part rom in a rar file although when you 'unrar' it should put them back together.
Most of what you need in terms of artwork should live at screenshot archive. If you are looking for something specific thats not hosted there let me know and I'll try to help out. I have most systems emulated using a front-end and have managed to source screenshots and other artwork for 90% of them.