| 摘要 |
<p>PURPOSE:To prevent omission of recording, by periodically demagnetizing a prescribed region from the present position to the end and outputting an alarm when the residual amount is at a threshold amount or below, through the instruction of demagnetization from a data processor. CONSTITUTION:A central processing system device CPU 2 of a data processor consists of an erase counter 21, a residual threshold amount register 22 and a comparison circuit 33. In the register 22, a specified value of the residual amount of a magnetic tape measured by taking a region erased with one operation from the stop position of a tape 5 loaded to a magnetic tape device 4 as a unit is stored. The CPU 2 erases a remaining specified region in the predetermined period, counts 21, compares 23 the region with a threshold value 22 and outputs an alarm 6 when the residual amount of the tape 5 is less than the threshold value. Thus, the constant residual amount of the tape 5 is kept, allowing to prevent the omission of magnetic recording. This system is suitable for a charge counter for electronic exchangers.</p> |
