Importance

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Abstract

A passive telephone line monitor is provided for keeping a log of telephone line activity, both incoming and outgoing, with a microcomputer (MCU) controlled by an onboard program read only memory (ROM) working with 64K bytes of random access memory (RAM) divided into 32 byte caches allowing for up to 2,000 phone call registers depending upon utilization of available space. One hundred Alpha Directory numbers can be stored from its keyboard for personalized caller identification. Upon power application, memory, input devices and registers are initialized, and time and date are entered from the monitor keypad. The microcomputer, an interrupt controlled device, detects monitor keyboard interrupt and displays the data on a liquid crystal display, and upon completion of date and time entry, the MCU clears all interrupt flags and displays current date and clock.

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First Claim