The Tokyo laboratory of Matsushita Electric Industrial's Communication Division (later the Matsushita Communication Industrial laboratory, and today Panasonic Mobile Communications) started work on the MADIC-I prototype in May 1958 and completed the prototype in April the following year. The prototype was modeled on the ETL Mark IV, which was developed at the Electrotechnical Laboratory. The MADIC-I's methodology and performance were very similar to the ETL Mark IV. The computer used six serial digits to represent one word and four parallel bits to represent one binary-coded decimal digit. It had a single address instruction methodology, an instruction set of about 30 instructions, a storage capacity of 1,000 words, and an addition/subtraction speed of 3.4 milliseconds, a multiplication speed of 4.8 milliseconds, and a division speed of 6.4 milliseconds. The hardware used around 400 bipolar transistors and about 4,000 diodes, and a magnetic drum (produced by Hokushin Electric Works — later Yokogawa Hokushin Electric, and today Yokogawa Electric) was used as the memory unit. A paper tape reader and a teleprinter were used as the input and output devices. The computer was housed in a desktop enclosure with the teleprinter (also called teletypewriter) positioned in the center.
The prototype was built as part of a feasibility study on computer commercialization. The later MADIC-II commercialization plan began from the results of this prototype study.