一种新型的可加密电话计费器的研制

A New Telephone Counter-timer Passable of Secret Code

介绍了一种新型的可加密电话计费器该系统采用中大规模集成电路，单片机技术设计。

This thesis presents a new telephone counter-timer which is passable of secret code.In this system,medium and large-scale intergrated circuit is adapted.It is designed by micro-processor 8031 technology.All functions are steady.