31 May
2000
31 May
'00
9:57 a.m.
Sellam wrote:
Broderbund came out with an 18-sector format for the
Apple ][, but in
order for the disk to be readble the first track is encoded as standard
16-sector format.
This 18-sector format provided two benefits: 1) increased storage space
and 2) a form of copy protection.
On some later Infocom titles for the Apple ][ family, they went to two
disk sides, and in order to maximize the amount of data on the second
size (and hence minimize flipping), they went to *one* sector per track.
This does away with the "wasted space" of intersector gaps.
Where they screwed up, though, was in sticking to a single byte of XOR
checksum over the entire "sector". The checksum scheme Apple used was
arguably inadequate for 256-byte sectors; it was truly horrible for
5.5 Kbyte sectors.