To provide a digital compression system where a storage device or the like having an analog element stores an analog/digital synthesis signal pulse resulting from compressed digital code pulse by using a combination of an analog element and a digital code, the analog/digital synthesis signal is transmitted through a communication line or the like with an analog element and a digital decompression decode circuit can store and communicate a digital pulse with a conventional TTL level, characters, audio and image data or the like.

A digital compression circuit 1 recognizes number of digital code in order to compress the digital code with the conventional TTL level, through the provision of an analog element, and provides the analog/digital synthesis signal to three pulse generating circuits to generate pulses with three different voltages. Using a storage device with an analog element and a communication line or the like stores and transmits the compressed analog/digital synthesis signal, and a digital decompression circuit decompresses and reproduces the analog/digital synthesis signal pulse with an analog element into a digital code pulse with a conventional TTL level. This system can be applicable to storage and transmission of characters, audio and image data or the like.