It would depend on the type of floppy. My Commodore 64's 5¼'' floppies from the mid-1980s still work mostly perfectly. These store about 170KB on each side, as do the earliest "single density" DOS floppies. Later "double density" floppies had twice the capacity, and "high density" twice that.
Wow - you're especially lucky given that you said "each side". One of the problems with Commodore floppies was that if you punched a notch to use the unintended "other side", you were taking a few risks:
- That side wasn't necessarily quality tested. Since disks, like CPUs today, were binned, you could often use the "bad" side anyway, as the failure rates went down on the production runs.
- That side didn't have a dust filter, or whatever you call those little felt pads.
- If it DID have a dust filter, it might have been in a position to catch the dust on a true double-sided drive, which would be spinning in the opposite direction, and so would end up being useless to you.
- Or, worse, if the pad was napped, like velour, spinning in the opposite direction would actually release all the dust that had been captured. That would be bad.
Or at least this was the lore that we passed around on BBS's at the time. It could have been every bit as wrong as the truism "When your computer crashes, try wrapping your disk drive in tinfoil" (which was in fact true if your problem was RF from the TV hitting the poorly-shielded-and-filtered serial cable, but otherwise either useless or a good way to overheat your drive).
Probably true. I don't remember ever regarding the B side as being of potentially inferior quality, however, or ever experiencing any data loss on the B side. I may have been lucky. The floppies I have today are one-sided, though.
Remembered some more now. First of all, "double density" floppies ("SSDD") could actually be used safely on both sides if you did the notch thing. Bona fide double-sided floppies ("DSDD") were eventually introduced.
