| 摘要 |
PURPOSE:To enable a simple circuit to detect an abnormal break in a memory unit of a recording medium due to a discontinuance of power by a direct comparison of values recorded on the medium of a memory unit where memory units are recorded in sequence. CONSTITUTION:On a recording medium, front area and back area 3 are provided centering on main information part 2 in the order that magnetic head 5 meets them, and values of counter 4 set by data register 7 are recorded. In a memory- unit reproducing process, contents from area 1 are supplied to data register 7 and set to register 9 in the same way as a memory process. After main information part 2 is reproduced, a recorded value from area 3 is extracted to data register 7 and comtents of data register 7 and register 9 are compared mutually to make a decision on whether abnormal interruption of a corresponding memory unit is caused in the last memory process due to a power break, etc. |
