Introduced by Intel in 1980, the 8051 microcontroller was revolutionary. Despite being over four decades old, its simple yet powerful architecture—featuring 4KB of ROM, 128 bytes of RAM, timers, serial ports, and I/O pins—has spawned countless variants from manufacturers like Atmel (now Microchip), Silicon Labs, NXP, and STC.
sbit DQ = P2^0; // 1-Wire data pin