NEAC-2203

NEC Corporation (NEC) developed the NEAC-2203 transistor computer based on the NEAC-2201 with the aim of achieving practical business processing, and delivered the first machine in May, 1959. In the exhibition of the AUTOMATH (AUTOMATH: International Conference on Information Processing sponsored by Unesco) that had been held in Paris in June, 1959, NEC exhibited NEAC-2201 and provided public demonstration for the first time as a commercial transistor computer in the world. Though vacuum tubes were used for the clock oscillator and the power supply and the peripheral circuitry of the magnetic drum unit in NEAC-2201, all these vacuum tubes are replaced with the transistors in NEAC-2203, and NEC added a floating point arithmetic mode besides a fixed point mode. The memory was composed of the hierarchy of three layers of magnetic core memory (240 words), high-speed magnetic drum (2,000 words and 10,000 rotations/minute),　and magnetic drums (10,000 words , 1,500 rpm , up to 10 drums). NEAC-2203 development was oriented towards EDPS (Electronic Data Processing System), and developing efforts were focused on peripheral equipment and their control units. Card readers, card punches, line printers, and magnetic tape units, etc. were developed and connected.

NEAC-2203 had interrupt functions, and was able to execute three programs by timesharing, so it was able to execute an operation of I/O and an arithmetic operation simultaneously. 30 sets of NEAC-2203 were shipped, and at that time, it was the marvelous number, and NEAC-2203 was used in various fields.