Development of the Magnetic Disc
As noted on the magnetic tape page, the biggest disadvantage of tape systems is that it is not possible to almost instantly find a particular piece of data on a tape without searching through, possibly, the entire length of it. The next priority then was to find a system which would allow near instantaneous access to individual items of data and the answer was the magnetic disk system, which comprises of a flat disc made, usually, of plastic or a non-ferrous metal, coated with extremely fine particles of iron oxide. Data is recorded onto the desk in a spiral pattern by a movable head which can scan right across the whole surface of the spinning disc. The head can be made to find and follow precise tracks of data on the disk, which are extremely close together in order to maximise the amount of information which can be stored. It is possible to stack such discs vertically and used multiple drive heads in order to store and access very large quantities of information. The first widespread use of magnetic desks was the floppy disc, which was made on a very thin and flexible plastic coated with metal oxide, it's bendable characteristics giving it its popular name. Floppies had to be handled extremely carefully in order to avoid damage to the thin surface recording film, and the amount of data that they could carry was very small compared to modern media, but in an era when personal computer systems were in their infancy and programmes, compared to those available today, were far smaller and required much less storage space, they were considered to be perfectly adequate for the purpose; and the huge advantage for software developers was that a floppy was very difficult indeed to copy!