For all its versatility, a microprocessor is not a self-contained computer on a chip. It cannot operate without the help of other ICs, like RAMs, ROMs and input/output chips that enable it to interact with other components. It was only a matter of time, then, before semiconductor firms managed to cram all that ancillary circuitry onto the same chip, along with the arithmetic and logic unit that makes up a microprocessor.
Texas Instruments was the first company to do this. Incredibly, considering the complexity of the task, TI engineers Gary Boone and Michael Cochran succeeded in creating the first microcontroller (also called a microcomputer) in 1971, about the same time that Intel fashioned the first microprocessor. But TI failed to take advantage of its invention as astutely as Intel capitalized on the microprocessor. Unlike Intel's chips, TI's microcontroller, a 4-bit device, wasn't put on the general market immediately, but was employed in a TI calculator introduced in 1972.
TI refined its invention over the years and finally offered it to the electronics industry in 1974. The TMS 1000 was produced in some forty different versions, with varying quantities of RAM and ROM, and about a hundred million have been sold so far. Part of the reason for its success was its unprecedented low price tag - a mere $2 in bulk orders.
Because of its low price, the chip has had its greatest success in consumer electronics, where it's used in calculators, toys and games, appliances, and burglar alarms. It is also found in photocopying machines and juke boxes. As much as any IC, the TMS 1000 has helped make the power of modern electronics available to everyone.