tm@polari.UUCP (Toshi Morita) (04/12/90)
-=-=-=-=-=-=-=-= toddpw@tybalt.caltech.edu (Todd P. Whitesel) writes: >But it is for that reason that data is never stored closer than 3/4 of a track >apart, and since 1/4 tracks are a pain to work with (you have to do gross >things with the stepper magnets) DOS only uses full tracks to store data. >Spiral tracking copy protection schemes use quarter tracks but spiral it >such that data is never closer than 3/4 track at any point on the disk >(assuming they are reading real data and not checking for the presence of >intentional errors). If I remember correctly, Br0derbund's spiral tracking (a la Choplifter) used adjacent half-tracks in concentric half-circles to achieve one of the most difficult copy-protechtion schemes ever, (not quarter tracks). Nice to see all the slick programmers (kadickey, nicholas) on Usenet! Toshi Morita ..!uunet!microsoft!uw-beaver!sumax!polari!tm