Early computers were enormous affairs, that oftentimes filled up entire rooms. Early technologists, however, were predicting in the 1950s that within a few decades these behemoths would be small enough to fit on a desk, and common enough that everyone would own one. Unlike many of the other extremely optimistic predictions of the era, this proved soon to be the case.
Until the end of the 1960s there was simply no way to shrink a computer past a certain point, even had it seemed that there was a need to do so. At the end of the 1960s, however, the military began to invest heavily in smaller computers for use in fighter planes. By 1970 the microprocessor had essentially been invented, drastically reducing the amount of size needed for a computer processor, and opening the door to smaller and smaller computers.
Minicomputers came on the scene a few years before the true first PCs. These were small enough to fit on a desktop, but prohibitively expensive for any normal consumer, making them somewhat different from the modern conception of a PC. Within a few years, however, the technology had trickled down, and the first PCs began to be created in hobbyists basements and garages.
In 1975, the first PCs produced as a mass-production kit were released by Altair, a year after a less complete kit-list was released as the Mark 8. These kits became enormously popular, with software written for them by two programmers, Paul Allen and Bill Gates, and their company Micro-Soft. A year later Stephen Wozniak and Steven Jobs started their own personal computer business, Apple Computer Company, also offering a kit along the lines of Altair. A year later the company released a pre-assembled version of their computer, the Apple II, which became virtually an overnight success.
In 1981, the International Business Machine (IBM) company decided to enter the personal computer world. With their massive resources and decades of experience creating mainframes, they released their own desktop, which they called the PC 5150. This was the first widespread use of the term PC, although it was only one of the first PCs.
These first PCs were a far cry from the computers of today, but had a surprising number of similarities. The Altair 8800 featured a motherboard with a number of slots for various cards which held things such as the memory and the CPU. On the front of the computer was a plate with various switches and lights, to input binary data directly into the computer and see instant feedback. Using these first PCs basically consisted of inputting complex programs into the computer by toggling switches in specific sequences.
A few years before the Altair 8800 was another of the first PCs, which, although it did not achieve widespread fame, did implement a number of important features which would later impact personal computers as a whole. The Xerox Alto was released in 1972, and had features such as a graphical user interface, the idea of a desktop upon which various items sat, and a mouse for interacting with the desktop. Although the Alto eventually faded into relative obscurity, many of the ideas it introduced would later be resurrected in Apple’s computers, and eventually in PCs as a whole.
By 1977, the first PCs were on their way to looking like modern PCs, and by the early 1980s they had most of the features, albeit in a less aesthetic and diminished capacity. Mice, full keyboards, disk drives, and RAM were all found on popular computers such as the Apple Macintosh, the Xerox Star, and the Atari ST. Color was widely introduced at this time, and over the years hardware became more robust, software became more efficient, and the internet offered a widespread connectivity, forever transforming these first PCs into modern machines that dwarf even the most powerful supercomputers of the 1970s.
