Nemo1985 wrote on 2023-02-27, 12:57:
The 77 tracks means that they have less than 1.2mb space available?
Space is defined by the format - though obviously the media material, quality and drive heads put an upper limit on what can be reliably recorded. 1.2MiB is just a standard among others, you could just as easily use another format: 1-sided for example, or put more sectors and less space between them like what FDFORMAT does to put 1.44MiB on 5.25" floppies.
IBM PC uses 15 sectors of 512 bytes per track, 80 tracks, 2 sides = 1228800 bytes. Some JP systems use 8 sectors of 1024 bytes per track, 77 tracks, 2 sides = 1261568 bytes. It's actually more space, and the simple answer would be "no, it doesn't have less than 1.2MB space available" but it's not that simple. Just FYI this is not a PC-compatible format and PC can't read such disks anyway because of different rotation speed (360 vs 300 rpm). Well unless you have hardware (3-mode capable FDC and drive) and software to support it.
A word of caution: Floppies marked as "77-track" one could have shorter cutout/window in the envelope for the heads to move in. It's rare (like a true 1-sided media), most have standard 80-track cutout, but there are exceptions.