If I remember right, the ST has a standard 720K PC DD compatable floppy drive.
"The disk drives used by Atari ST computers are industry standard 360K or 720K double-density floppy drives, exactly the same as those in PCs... at least in those days.
PC drives can be used as replacement drives, only nowadays it is difficult to find 720K drives. You can however use just about any 1.44Mb HD drive as these will perform perfectly well in DD 720K mode."
You can copy ST-roms to a ordinary PC floppy (with a disk image dumping app like Makedisk) and then run them on the real ST.
very good ST link:
http://www.megacom.net/~q-funk/ST/
