A microcontroller was developed in 1971 by Intel Corporation in the United States.
That is the 4 bit microcontroller called i4004.
It was ordered by a Japanese company BUSICOM for calculators.
Later, the contract was changed and it was sold as a general-purpose microcontroller with success.
After that, Intel Corp. developed a 16 bit microcontroller ‘8086,’ following the 8 bit microcontrollers such as ‘i8008’, ‘i8080A,’ and ‘i8085.’
After developing several microcontrollers, they continue to develop the CPUs used in current personal computers.
Toshiba developed a 12 bit microcontroller TLCS-12 in 1973.
At that time, the United States was considering electronic control units as a countermeasure of the exhaust gas regulation law.
Against this background, Toshiba's 12 bit microcontroller was developed as Ford's in-vehicle engine controller.
After that, Toshiba developed a wide range of high-level microcontrollers from 4 bit to 32 bit or higher.