These split archive files are often created for convenience so that you can download a large file over the internet without having to get the whole thing at once—you can just download each part individually. Split files like this are also useful for storing a large archive on something like a disc. If the storage device can only hold, say, 700 MB, but your archive is five times that size, you could split it into five parts and then store each one on a separate disc.
How to Open an R00 File
You can open R00 files using just about any program that supports RAR files, including the free PeaZip tool, as well as several other free zip/unzip programs. However, it’s likely that if you have one, you also have an R01, R02, R03… etc. You must go through a different process to open multiple .RXX files than you do when there’s just one. To open multiple archive volumes at once, you must first make sure that all of the different parts—the files that have the extension .R00, .R01, etc., are in the same folder. Missing even one will break the archive and probably won’t even let you combine them into one single file. Then, you just have to extract the .R00 file. The program should automatically detect the other part files and combine them together, and then extract the contents.
How to Convert an R00 File
R00 files are only part files, so it would be a tedious process to try to convert each .RXX file to another archive format. Each part is just that anyway: a part of the larger archive, so it wouldn’t be very beneficial to have a partially converted file. However, once the different parts have been combined and the contents extracted, you can use a free file converter to convert the extracted files to a different format. For example, even though you can’t convert a single .R00 to ISO, AVI, etc., you can extract the ISO or other files out of the .RXX archive once you’ve joined the pieces, and then use a free file converter to convert those extracted files to a new format.
Still Can’t Open It?
If your file isn’t opening like described above, it’s possible that you’re confusing an ROM file for an R00 file. The former is a Read Only Memory Image file that should open with a program like Basilisk II or Mini vMac. Or maybe you have an ROL file, which is an instrument file used by programs like Ad Lib Visual Composer and Audio Overload.