| 摘要 |
PURPOSE:To protect the content of a save register so that an unexpected affair does not take place to the user, by providing a means inhibiting the shelter operation exceeding the number of data shelter registers, for an electronic desk top calculator making mixed calculation such as calculation in paretheses, addition, subtraction/multiplication/division. CONSTITUTION:When keys of a key input section 10 are operated according to the order of numeric equations, an operation control section 11 transfers data of the input section 10 to X registers 31, 21 and Y registers 32 and 22 sequentially. When the input section 10 discriminates that a multiplication and division key or left parenthesis (key) is operated and it is required for the control section 11 to save the result of on the way, a signal 101 or 102 is transmitted to a gate 12 or 13. Furthermore, A signal A of key operation, preceding addition/subtraction data for the operation of multiplication/division keys are sheltered. A signal B is inputted to gates 62 and 72 and data in Y register is sheltered registers 33 and 23. The addition/subtraction data is sheltered to the save register one after another and sheltered to registers 36 and 26, if a shelter request is further given, the output of the register 36 goes to 1, the output of an inverter 67 closes the gates 12 and 13 to inhibit shelter operation. |
