Since the CD was originally designed for audio, its REAL capacity is 74min x 60secs x 2bytes/sample x 2channels x 44100 Hz = 783,216,000 bytes.
So where's the rest? ISO9660 uses 2048 bytes/sector for data instead of the native 2352 bytes/frame (1 frame = 1/75sec) plus 304 bytes for additional redundancy. This yields 681,984,000 bytes for a 74min CD and 737,280,000 bytes for 80min.
If you're burning an audio CD, VCD or SVCD you will actually be able to use that capacity (CDXA).
If you need more capacity, just use DVD+/-Rs. CD blanks with >80 mins can raise weird problems (e.g. try to skip to the last track on a 99min audio CD) because the standard has no way to handle those sizes.
