| 摘要 |
PURPOSE:To protect a program area by dividing a magnetic storage device into a program storage area and a data storage area and controlling the data transfer from a semiconductor storage device to the program storage area by an enable/disable flag. CONSTITUTION:The data among a utility program (UTL) 1, a program (PRG) 2 and a magnetic storage device 4 are transferred 7 mutually and a data 3 and the data of an auxiliary storage device 4 are transferred 8 mutually. An I/O handling program (IOX) 5 participates in both transfer 7, 8, and a flag 6 participates in the IOX 5 and when the flag 6 is set, whether or not the area of the magnetic storage device 4 being a destination is program storage area is checked in case of the transfer from the semiconductor storage device to the magnetic storage device 4. When the area is the program storage area, an error message is outputted to stop the system. |
