In July of 1970, Electronic Arrays(EA) announced that it had developed a calculator chip set 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 chip set. 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 chip set as advertised at introduction was just under $200 for a single six-chip set. 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 package.

Initially, the plan that EA had was to sell the chips in volume quantities to anyone who wanted them to make a calculator of their own, including any small companies that had a desire to get into the highly dynamic electronic calculator marketplace without the extreme expense involved in designing the logic for a calculator, and having to contract with a chipmaker to create custom integrated circuits.

Those plans changed somewhat quickly, when an office machines importer/ distributor just down the street from Electronic Arrays said they wanted EA to make a calculator for them using the S-100 chip-set. While EA did sell chips to electronics distributors and other calculator manufacturers, this situation with the local office machines distributor changed the game a bit. More information on this can be found in the Old Calculator Museum exhibit for the ICM 816 calculator.

The S-100 chip set, and subtle variants executed with six chips, was quite popular, and were used by Sony, Lago Calc, MITS, Walther and others. Due to advances in Electronic Arrays' IC fabrication technologies EA 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. Over time, EA released chip-sets with four, then two, and eventually a single chip.

Initially, Electronic Arrays chip technology allowed them to gain a foothold in the MOS/LSI chip marketplace, manufacturing Read-Only Memory Chips (ROM), Random Access Memory chips (RAM), and calculator chips, all using PMOS integrated circuit processes. By the time that competition was building for open-market calculator chip-sets, NMOS IC technology had become a force in making chips that would run at higher speeds and draw less power. EA was somewhat behind the curve in chip technology, sticking with their PMOS processors while others went on to develop and refine NMOS fabrication lines, with other chip-makers such as Texas Instruments and Mostek, as well as Japanese chip-makers Hitachi, NEC, and Toshiba developing lower-cost chip sets and eventually single-chip devices that came out before to compete with Electronic Arrays' chips. Over time, Electronic Arrays' market share diminished, and the company fell on hard financial times. Electronic Arrays was finally sold to Japanese chip-maker NEC in 1978.