| 摘要 |
PURPOSE:To prevent a illegal use by introducing a current parity number via an arithmetic means prior to the start of communication, comparing the parity number with a regular parity number stored in advance in a storage means and disabling the start of communication when both are dicordant. CONSTITUTION:A manufacture number storage means 3 stores a manufacture number specific to a portable telephone set and a parity number storage means 4 stores a regular parity number calculated from the manufacture number by a calculation in advance. An arithmetic means 3 reads the manufacture number from the means 3 and makes arithmetic operation. A comparison means 8 compares a parity number in the means 4 with a parity number from the current manufacture number calculated by the means 7 and issues the command of setting an inhibiting flag in a ROM when the both are different and sets no flag when they are identical. A key locking means 9 checks an inhibiting flag area in the ROM and disables the start of communication of the portable telephone set when the flag is set. An alerting means 11 is activated by the command of setting a flag from the means 8 to activate a display device 10, thereby displaying the disabled communication of the portable telephone set. |
