| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the abnormal operation of a drive by preliminarily storing the first check sum of normal data of a previously written driving program and calculating the second check sum of data every impression of an application execution command and comparing it with the stored first check sum and judging that the program is normal when they are equal. SOLUTION: When a host computer 10 impresses the rewrite instruction of a driving program on an optical disk device 20, a decoder 21 outputs an instruction code in accordance with the rewrite instruction to a control part 23, which reads out all data of an already written driving program to calculate a second check sum and compares it with a preliminarily stored first check sum. In the compared result, when the first check sum and the second check sum are equal, the part 23 Judges that the previously written driving program is normal and the part 23 uses it to drive a drive. Thus, checkings about whether the driving program of a flash memory 24 is normal or not are made possible at the time of performing a rewrite and every time a power is supplied.</p> |
