User`s guide

Although 2MG, Diskcopy, and some other 800k image formats have file sizes
greater than 800k, on a ProDOS diskette they will often occupy a good deal less
space. You will often be able to transfer such files (e.g. via a NULL modem
connection) to an Apple II 800k diskette so long as you employ a protocol which
does not pre-send size information, such as X-modem.