The first personal computer is generally recognized as the Kenbak-1 , designed by John Blankenbaker in 1971. It had 256 bytes of memory and used small- and medium-scale integrated circuits but was not based on a microprocessor, as microprocessors had not yet been invented at that time. The Kenbak-1 sold only about 40 units and had limited influence

. The first personal computer using a microprocessor was the Micral , designed in France in 1973, which used the Intel 8008 microprocessor

. However, the first commercially successful personal computer that ignited the microcomputer revolution was the Altair 8800 , introduced in 1974 by Micro Instrumentation and Telemetry Systems (MITS). It was based on the Intel 8080 microprocessor and became widely influential, leading to the development of software like Microsoft's first product, Altair BASIC

. Following that, in 1976 , the Apple I was introduced by Steve Jobs and Steve Wozniak, and in 1977 , three major personal computers were released that became widely popular and are often referred to as the "1977 Trinity": the Apple II, Commodore PET, and TRS-80. These machines marked the beginning of mass-market personal computing

Summary:

• Kenbak-1 (1971): First personal computer, not microprocessor-based, limited sales.
• Micral (1973): First microprocessor-based personal computer.
• Altair 8800 (1974): First commercially successful personal computer, Intel 8080 CPU.
• Apple I (1976): Early personal computer kit.
• Apple II, Commodore PET, TRS-80 (1977): First widely popular mass-market personal computers.

Thus, the very first personal computer by design and introduction was the Kenbak-1 in 1971, but the first commercially impactful personal computer was the Altair 8800 in 1974