In the large computer field at the time, imports were increasing year by year, and the Ministry of International Trade and Industry was working to achieve domestic production of large computers by providing subsidies. To achieve this, the Electronic Computer Technology Research Consortium was formed in July 1962 by three companies -- Fuji Telecommunications Manufacturing (currently Fujitsu), NEC and Oki Electric Industry. The FONTAC (Fujitsu-Oki-Nippondenki-Triple- Allied-Computer) was a large computer completed in November 1964 after 3 years of joint research by these 3 companies. The FONTAC was delivered to the Japan Electronic Industries Development Association.
As its main computer, the FONTAC system used the FONTAC Central, a large binary computer with a high-speed, high-capacity memory unit and multiple input/output channels. As satellite computers, the system used the FONTAC Sub I with variable word length and the FONTAC Sub II with fixed word length. The main computer and satellite computers were tightly coupled. The FONTAC Central was a binary computer using 42-bit words. Fixed point values were comprised of 36 data bits, 4 flag bits and 2 parity bits, and floating point values were comprised of 9 characteristic bits, 27 mantissa bits, 4 flag bits and 2 parity bits. A maximum memory capacity of 65,536 words was achieved by using a 30mil magnetic core memory with cycle time of 2.2 microseconds for the memory unit. Arithmetic speed performance was 4.4 microseconds/25.2 microseconds for fixed point addition-subtraction/multiplication, and 15.4 microseconds/30.8 microseconds for floating point addition-subtraction/multiplication.
Fuji Telecommunications Manufacturing (currently Fujitsu) was in charge of the CPU in the FONTAC project, and they later enhanced the FONTAC Central based on the technology developed in the joint research, commercializing it as the FACOM 230-50.