| 摘要 |
PURPOSE:To constitute a titled apparatus so that a program is not broken down even in the event of a misoperation of a key, by providing a switch for supplying a read-out/write-in control signal to a readable/writable memory for storing the program. CONSTITUTION:In an electronic computer, etc., an ROM13 for storing a program and also a readable/writable RAM12 for storing an optional data are provided, in addition to which readable/writable memory modules M1-M4 for forming a program package are connected through a connector. A necessary program is written in advance in th modules M1-M4, and a switch is provided on a control line R/W for supplying its read/write control signal. In a state of the switch as shown by the figure, a write signal is supplied to only the RAM12 and the M4, and the write signal is not supplied to M1-M3, but they are used as ROMs. Accordingly, even in the event of a mis-operation of a key to M1-M3, a program stored in them is not broken down. |
