Abstract: A switching system (3) has, in addition to an ordinary accounting function, an origination-only accounting control unit 6 to monitor the number of message units used by an origination-only portable telephone (1B) identified by a terminal identification number and to deny the origination of a call by the origination-only portable telephone (1B) upon the increase of the number of used message units to a predetermined number. The origination-only accounting control unit (6) accepts the origination of a call made by the origination-only portable telephone (1B) when a prescribed input about the origination-only portable telephone (1B) is given thereto by a system operator by operating a predetermined terminal device (7) or the like after the denial of origination of a call by the origination-only portable telephone (1B).

Abstract: A retract mechanism for a magnetic head which can read from and/or write to a disk, the mechanism includes a spring arm which supports the head and urges the head toward the disk. The spring arm includes a cam follower which rides along the surface of the cam, which has two parallel horizontal surfaces and two incline surfaces. The spring arm is moved by an actuator in a radial direction along the disk. When the spring arm is moved radially away from the center of the disk, the cam urges the spring arm upwardly, thereby lifting the head up and away from the disk. As the spring arm continues to move radially away from the center of the disk, the cam guides the spring arm such that the head rests safely on a landing platform.

Abstract: A dustproof type magnetic disc apparatus has structure for starting rotation of a magnetic recording medium, after driving a blower for dust separation for a predetermined time, by putting on a start switch for driving the magnetic recording medium.

Abstract: A retract mechanism for a magnet head which can read from and/or write to a disk, the mechanism includes a spring arm which supports the head and urges the head toward the disk. The spring arm includes a cam follower which rides along the surface of the cam, which has two parallel horizontal surfaces and two incline surfaces. The spring arm is moved by an actuator in a radial direction along the disk. When the spring arm is moved radially away from the center of the disk, the cam urges the spring arm upwardly, thereby lifting the head up and away from the disk. As the spring arm continues to move radially away from the center of the disk, the cam guides the spring arm such that the head rests safely on a landing platform.

Abstract: A retract mechanism for a magnetic head which can read from and/or write to a disk, the mechanism includes a spring arm which supports the head and urges the head toward the disk. The spring arm includes a cam follower which rides along the surface of the cam, which has two parallel horizontal surfaces and two incline surfaces. The spring arm is moved by an actuator in a radial direction along the disk. When the spring arm is moved radially away from the center of the disk, the cam urges the spring arm upwardly, thereby lifting the head up and away from the disk. As the spring arm continues to move radially away from the center of the disk, the cam guides the spring arm such that the head rests safely on a landing platform.