11.2 Zones


As mentioned in the preceding section, each surface of the disk is divided into zones, with head 0 used for zones 0-7 and head 1 used for zones 1-8. Blocks within the same zone are the same size. Thus, either head 0 or head 1 would give the same size for a block in zone 1.

Relation Between Zone Number and Block Size

Zone Number Block Size
Zone0 19720 bytes
Zone1 18360 bytes
Zone2 17680 bytes
Zone3 16320 bytes
Zone4 14960 bytes
Zone5 13600 bytes
Zone6 12240 bytes
Zone7 10880 bytes
Zone8 9520 bytes

The number of tracks included in each zone is as follows.

Relation Between Zone Number and Number of Tracks

Zone Number Number of Tracks
(Head 0)
Number of Tracks
(Head 1)
Zone0 134 --
Zone1 146 146
Zone2 137 146
Zone3 137 137
Zone4 137 137
Zone5 137 137
Zone6 137 137
Zone7 102 137
Zone8 -- 102

Thus, for example, Zone 0 has 134 tracks, or 268 blocks, and 19,720 bytes of data can be stored in each block. The capacity of Zone 0 is therefore 268 x 19,720 bytes, or 5,284,960 bytes.

Relation Between Zone Number and Zone Size

Zone Number Size with Head 0 Size with Head 1 Zone Size
Zone0 5,284,960 bytes -- 5,284,960 bytes
Zone1 5,361,120 bytes 5,361,120 bytes 10,722,240 bytes
Zone2 4,844,320 bytes 5,162,560 bytes 10,006,880 bytes
Zone3 4,471,680 bytes 4,471,680 bytes 8,943,360 bytes
Zone4 4,099,040 bytes 4,099,040 bytes 8,198,080 bytes
Zone5 3,726,400 bytes 3,726,400 bytes 7,452,800 bytes
Zone6 3,353,760 bytes 3,353,760 bytes 6,707,520 bytes
Zone7 2,219,520 bytes 2,981,120 bytes 5,200,640 bytes
Zone8 -- 1,942,080 bytes 1,942,080 bytes
TOTAL 33,360,800 bytes 31,097,760 bytes 64,458,560 bytes