Broader Description of Tracks, Heads, and Sectors
In the previous writing I discussed a little about the Hard Drive Capacity but did not go into much depth. This could leave some confusion about the amount of data stored because of not knowing how each of these parts work. When looking at the “Head” this is the part of the Hard Drive that actually reads and writes data either to or from the platters on the hard drive. If you Google these parts you can find pictures and as the saying goes, a picture is worth a thousand words. In this case, that certainly applies. The picture will show the head as being more like an arm and this arm extends over the platters which are spinning. Some platters spin at a rate of 10,000 revolutions per minute (RPM) and this arm is a paper thin distance above the platters. This is measured in nanometres and if you looked to try to see between the head and the platters the naked eye probably could not detect a space in this small separation. Hard Drives normally have multiple platters and the platters are two sided with data on both sides. The heads or arms that read and write data are on both sides of the platter and work simultaneously transferring or reading data. Not all platter are two sided however as is the case with floppy disk drives.
As in earlier writings I have mentioned tracks but did not explain in depth. Tracks are sometimes referred to as cylinders but mean the same thing. These are the tracks going around the platter in ever decreasing circles if looking from the outside edge toward the inside where the small hole is in the center. You can see the results of writing to the platter if you will take the CD disk out and look at the shinny side. You will see a difference in the tracks and notice it writes from the inside toward the outside of the platter.
The sectors on the disk are addresses on the tracks and on the older disk there were 17 sectors and all were the same size and contained equal amounts of data or 512 bytes of data regardless of the radius of the track. Looking at the track you understand from the inside near the hole in the center toward the outside edge the radius the size changes but the sector which contains the data remains the same regardless of where it is on the track, and it contains 512 bytes of data. A bit is one single piece of data and a byte is equal to eight bits. If reading this in literature or from Compact Disk information if it is bytes it would be written as MB (Notice the capitol B) for megabytes or Mb (Notice lower case b) for megabits.
