RAISING RECORDING DENSITY IN DIGITAL MAGNETIC RECORDERS.

Digital magnetic recording (DMR) is a basic technique in metrology; the performance of such methods is supported by good engineering and working characteristics, simplicity of computer interfacing, and low costs in development, production, and operation. Advances in DMR systems involve not only improving parts of the recording system (magnetic heads, media, and mechanisms) but also new methods which provide high record densities. Group modulation enables one to increase the capacity of binary-code transmission systems for a given passband; its essence is that each of the combinations of bits forming a group should correspond to one of the possible positions (values) of the signal in the medium.