Both Pascal and DOS 3.3 use the same recording format on the diskettes.
Pascal can read a DOS diskette with the UNITREAD procedure, but there is a
hitch: Pascal uses 512 byte blocks, while DOS uses 256 byte sectors. The
following table shows the correspondence between Pascal's block number and
DOS's track and sector numbers. Columns 4 and 5 refer to bytes 0..255 of the
block and columns 2 and 3 refer to bytes 256..511.
(1) (2) (3) (4) (5)
BLOCK TRACK SECTOR TRACK SECTOR
6 1 0 1 E
7 1 D 1 C
8 1 B 1 A
9 1 9 1 8
10 1 7 1 6
11 1 5 1 4
12 1 3 1 2
13 1 1 1 F
14 2 0 2 E
The rest of the disk is arranged the same, except that the track number
increases.