This more efficient GCR scheme, combined with an approach at constant bit-density recording by gradually increasing the clock rate ( zone constant angular velocity, ZCAV ) and storing more physical sectors on the outer tracks than on the inner ones ( zone bit recording, ZBR ), enabled Commodore to fit 170 kB on a standard single-sided single-density 5.25 " floppy, where Apple fit 140 kB ( with 6 and 2 GCR ) or 114 kB ( with 5 and 3 GCR ) and an FM-encoded floppy held only 88 kB.
