Abstract: In a pin-board matrix switch X- and Y-direction patterns are arranged in the X and Y directions to constitute a matrix. Crosspoint holes are formed at the crosspoints between the X- and Y-direction patterns. Each crosspoint hole has contacts formed therein. The contacts are connected to the patterns. A connecting pin has contact springs. The connecting pin is selectively inserted into the crosspoint holes to electrically connecting the contacts of the X-direction patterns and the Y-direction patterns which are adjacent to each other in the Z direction. Insulating members are arranged between the X- and Y-direction patterns. At least one pair of the X-direction patterns and the Y-direction patterns is constituted by first and second wiring layers arranged in the Z direction via insulating members.

Abstract: m bit data words are converted into one or two n bit (n>m) record words wherein the absolute value of a recording current is less than a predetermined value so as to eliminate a DC component from the recording current. Reproduction is made according to a partial response method thus enabling high linear bit density.