GB1096752A - Record playback apparatus - Google Patents

Abstract

1,096,752. Recording and playback. TRAINING AIDS (BRISTOL) Ltd. May 13, 1966 [Feb. 15, 1965], No. 6379/65. Heading G5R. In an arrangement for playing back sets of information signals arranged in a predetermined sequence on a medium such as magnetic tape, and which may correspond to sound and/or vision containing information or instructions for use by operators who carry out the instructions or by students who absorb the information, or to sets of instructions for carrying out a test procedure, the information is arranged in main and subsidiary sets in a first signal channel. Control signals are recorded in a second channel to identify the main sets and in a third channel to identify and start the subsidiary sets. Further control signals in a fourth channel are arranged in a coded sequence and related to both main and subsidiary sets of information. A logical control system is arranged to be operated from external switches to actuate the tape drive mechanism to present a particular set of information signals to the signal pick up heads and to arrange that the second channel is read when the next main set is reached and the third channel is read when the next subsidiary set is reached, to indicate the movement of the record to the control arrangements. When a particular information set is being played back, the fourth channel is read and the coded signals it contains are stored; to provide stop signals when the end of the particular set is reached. The external actuating switches enable the instructions YES, NO and REPEAT to be given to the control logic. After a main information set has been played, the tape stops in response to the coded control signals picked up from the fourth track. If the YES switch is next operated to show, for example, that a test has been successfully carried out, the tape is fast wound forward to the next main set and is stopped there by a signal picked up from the second track and then played at normal speed. If the NO switch is operated an appropriate subsidiary set of information which may be a fault finding sub-routine is selected in response to the coded signal by the control logic and played, and so on. The system may be used to control a projector drive in synchronism with sound information signals. The apparatus may incorporate facilities to enable particular sets of information to be searched for and played back, the information being located by coded addresses in the second track which are compared with a required address set up by selector switches. A system of interlocks prevents external signals reaching the logic circuits while the tape is moving.