------------------------------------------------------------------------------- the 3.5 inch floppy disk 2023-01-10 ------------------------------------------------------------------------------- AKA the 3.5" or 3½-inch floppy disk appeared 1984 $ units '3.5 inch' mm # 88.9 mm DS = double sided, 80*2 = 160 tracks DD = double density, uses an iron oxide coating with 135 TPI capacity: 720 KB on a PC 800 KB .... Mac 880 KB .... Amiga "read only" switch ------------------------------------------------------------------------------- https://dataswamp.org/~incal/floppy/floppy-data.txt incal@dataswamp.org -------------------------------------------------------------------------------