News Archive - Announcment of Electronic Arrays 6-Chip Calculator Chipset
In July of 1970, Electronic Arrays announced that it had developed a
calculator chipset that provided a four function, fixed decimal, eight-digit
(with calculation results to 16 digits) calculator on six LSI chips that
the company dubbed the S-100 chipset.
The chips were split by their function, with a Register Chip (5001),
Control Chip(5013), Output Chip (5005), Input Chip (5004), Arithmetic
Chip (5017) and Microcode ROM (5014).
The cost for a complete chipset as advertised at introduction was just
under $200 for a single chipset. When availability was announced
a few months later, the price had dropped to $156.47 for a set.
Each of the ICs was packaged in a standard 24-pin DIP (Dual Inline Package)
format, initially in a ceramic package, but later, in a less-expensive plastic
In November of 1970, Electronic Arrays created a subsidiary company called International Calculating Machines (ICM) headquartered in Woodland Hills, CA, and began producting a calculator using the chipset. The calculator, called the ICM 816, was introduced in early 1971.
The S-100 chipset, and subtle variants executed with six chips, was quite popular, and were used by Sony, Lago Calc, MITS, Walther and others. Over time, Electronic Arrays, due to advances in its IC fabrication process, was able to combine the functions of some of the chips into single chips, for example, combining the Arithmetic and Register chip, to reduce the number of chips to five, then four, to two, and eventually into a single chip. However, Electronic Arrays was somewhat behind the curve in chip technology development, with other chipmakers such as Texas Instruments and Mostek, as well as Japanese chipmakers Hitachi, NEC, and Toshiba developing lower-cost chipsets and eventually single-chip devices that came out before Electronic Arrays' chips. Over time, Electronic Arrays' market share diminished, and the company fell on hard financial times. It was finally sold to Japanese chipmaker NEC in 1978.