High-Density Binary Recording Using Nonsaturation Techniques

Commercially available magnetic tape units have longitudinal recording densities of up to 2000 bits per inch, whereas analog instrumentation recorders are capable of recording up to 10,000 cycles per inch. These figures contrast with a theoretical recording density limitation for iron oxide of 250,000 bits per inch, and the reasons for this discrepancy are analyzed. Two experimental systems having recording densities of 5000 and 10,000 bits per inch using analog recording techniques are described, Conclusions drawn from these experiments indicate that a density of 20,000 bits per inch should be possible using commercially available analog tape recording machines. Experimental machines indicate the practicability of densities on the order of 100,000 to 200,000 bits per inch, depending on the method of recording used.