| 摘要 |
PURPOSE:To perform normal operation even when the type of a ROM stored with a program is different and to eliminate the need for manual switching even when a different ROM is packaged by putting in a program for turning on and off a gate into an initial program. CONSTITUTION:When the ROM which is run firstly after a CPU is reset is a ROM1, this is fixed and the program which turns on and off the gate is put in its starting initial program to perform software switching to 27256 when the gate is turned on according to the kind of another ROM or to 27128 when off. The terminal OUT of the gate circuit is connected to the socket of the 27th pin of the ROM and when the program is run immediately after the power source is turned on, the program is run in the ROM1 and ROMs 2-4 are irrelevant to the program execution and fixed to 27128 or 27256 once the program is run. Consequently, a different ROM is usable without altering the hardware even when the different ROM is packaged.
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