An Introduction to Emulating: ROMS

2019-03-27 Jedite83

The “ROM”
The dictionary definition of ROM is ‘memory hardware that allows fast access to permanently stored data but prevents addition to or modification of the data’. But within the realm of video game emulation, the ROM has a different definition. It is a file that contains all the data from a single video game cartridge. It can be played on your computer by using a video game emulator.
Video game ROMs are relatively small and are easy to find on the Internet. The video game systems that apply to ROMs are any system that uses carts – such a NES, SNES, Gameboy/Color, Gameboy Advance, Genesis, N64, Atari… basically every 8-bit and 16-bit system, and many portable systems.

The “ISO”
When people are talking about ISOs, they’re talking about CD video games. These games include PSX, PS2, Saturn, Dreamcast, XBox, GameCube, etc.. An ISO is a file or archive of files that build up a single CD video game. Some emulators allow you to play an ISO as if it were a ROM (by going to File > Load Game), but others require you to use certain burning software to burn the ISO onto a CD, then play it with the emulator via your CD-ROM. Video game ISOs are very large ad are not so easy to obtain on the internet. You’ll even come across websites that ask for a fee in order to gain access to their ISOs downloads – but don’t do it! Keep on looking for free places.

The “ISO/MP3”
This only applies to Sega CD and TurboGrafx16-CD games, which are both classified as classic CD video games. Classic CD video games are audio CDs, the only exception is that the first or second audio track is actually a data track. This data track is where the game’s data is stored. The audio tracks of the rest of the CD are all the songs of the game. ISO/MP3 is how emulation websites distribute Sega CD and TurboGrafx16-CD games. An ISO/MP3 archive includes 1 ISO file and a whole bunch of MP3s. The ISO file is the data track of the game and the MP3s are all of the audio tracks. Like regular ISOs, ISO/MP3 archives are large and difficult to find on the internet.

Compression
When your downloading your roms, you will come accross several different forms of compression.
.zip – a very common file compresion format, dating back to the 1980’s. Due to its popularity, a large number of emulators can access roms inside of zip compressed files without having to uncompress them first.
.rar
.7z – my prefered compression format for when my emulator dose not support reading from a compressed file. .7 files tend to be smaller then the more popular .zip files. I recommend downloading the 7-zip program, as it supports not only its native .7z, but also most of the other popular formats, including zip and rar.

Are games too big? Will they fill up my computer?
Not at all! The following are some estimates on how large video game ROMs can be:

NES, Game Boy/Color, SMS/Game Gear ROMs (zipped) = 50 KB – 300 KB
SNES ROMs (zipped) = 500 KB – 2.5 MB
N64 ROMs (zipped) = 7 MB – 20 MB
GameCube ISOs = 1 – 2 GB
Game Boy Advanced ROMs (zipped) = 1 – 7 MB
Playstation ISOs = 500 MB – 700 MB
Playstation 2 ISOs = 1 – 4 GB
Genesis ROMs (zipped) = 500 KB – 1.5 MB
Sega CD and TurboGrafx16-CD ISO/MP3s (unzipped) = 80 MB – 150 MB
Dreamcast = 800MB – 1.2GB
TurboGrafx16 ROMs (zipped) = 100 KB – 300 KB
Arcade ROMs (zipped) = 20 KB – 80 MB

Rom Naming
It is common

Standard Codes:
	[a] - Alternate
	[b] - Bad Dump
	[BF] - Bung Fix
	[c] - Cracked
	[f] - Other Fix
	[h] - Hack
	[o] - Overdump
	[p] - Pirate
	[t] - Trained
	[T] - Translation
	(Unl) - Unlicensed
	[x] - Bad Checksum
	ZZZ_ - Unclassified
	[!] - Verified Good Dump
	(???k) - ROM Size

Special Codes:
	[C] - Color GameBoy
	[S] - Super GameBoy
	(M#) - Multilanguage (# of Languages)
	[M] - Mono Only (NeoGeo Pocket)
	(PC10) - PlayChoice 10 (NES)
	(1) - Japan (Genesis)
	(4) - USA (Genesis)
	(5) - NTSC Only (Genesis)
	(8) - PAL Only (Genesis)
	(BS) - BS ROMS (SNES)
	(ST) - Sufami Turbo (SNES)
	(NP) - Nintendo Power (SNES)
	(Adam) - ADAM Version (Coleco)
	(PAL) - PAL Video
	(PD) - Public Domain

Country Codes:
	(A) - Australian
	(C) - Chinese
	(E) - Europe
	(F) - French
	(FN) - Finland
	(G) - German
	(GR) - Greece
	(HK) - Hong Kong
	(I) - Italian
	(J) - Japan
	(K) - Korean
	(NL) - Dutch
	(S) - Spanish
	(SW) - Sweden
	(U) - USA
	(UK) - England
	(Unk) - Unknown Country
	(-) - Unknown Country