The first trinity: the Commodore PET, the Radio-Shack TRS-80, and the Apple ][ (1977-1980)

Despite the success of the Altair, the big computer companies still considered these small machines to be the domain of a few slightly screwy enthusiasts, and not a product for the mass market. This didn't stop many of these same enthusiasts from starting their own computer companies, almost all of which no longer exist today.

There was Processor Technology's Sol, designed by Lee Felsenstein who went on to design the first "portable" computer, the Osborne 1. There was Cromemco, which was started by two Stanford students, and made add-on boards for the Altair before designing their own computer products. Vector Graphic also started making S-100 memory boards before introducing their own computer system. A company called IMSAI built an Altair clone and had the distinction of having the first personal computer ever to be featured in a movie, Wargames, before imploding due to overexpansion and forced est training for management that distorted fiscal realities. SouthWest Technical Products (SWTP) built a machine using Motorola's new 6800 CPU. In the UK, the NASCOM-1 kit attempted to mirror the success of the Altair on the other side of the Atlantic.

By the end of 1976, over 40,000 personal computers had been sold, with MITS selling approximately 25%, IMSAI 17%, Processor Technology 8%, and SWTP 8%. There were dozens of other companies selling computers. Many of them sold too few products to even show up on the radar. In ten months, Steve Jobs and Steve Wozniak had managed to sell only 175 units of the hand-assembled Apple I motherboard, which lacked a keyboard, monitor, or even a case.

From left to right: a Vector Graphic, SOL-20, SWTP 6800.
Bottom row: NASCOM-1, Apple I, Cromenco Z-2, IMSAI 8080

The stage was set for the a second, more professional, group of electronics companies to introduce their own products.

The
holy trinity: Commodore PET, TRS-80 Model I, and the Apple ][

The first of these was a calculator firm called Commodore, which was started as a typewriter repair company in 1954 by Auschwitz survivor Jack Tramiel. When Texas Instruments started their price war that nearly drove MITS out of business, Tramiel realized that it was vital for his company to own semiconductor technology that could produce chips in-house, just like TI did. He found ex-Motorola engineer Chuck Peddle, who had invented a vastly cheaper 6800 clone called the 6502. Commodore bought Peddle's company, MOS Technologies, and let him continue working on his own projects. One of these projects became the PET computer, ostensibly standing for Personal Electronic Transactor, but Commodore engineers sometimes called it Peddle's Ego Trip after it wound up becoming a smash success.

The PET had its own built-in monitor, keyboard, and tape drive, giving early computer users everything they needed to start working. It even had a version of BASIC purchased from Bill Gates' tiny Micro-Soft company. The keyboard was a cheap "Chiclet" job that was replaced in later models. Commodore sold 4,000 PETs in 1978 and sales kept rising. A base model PET sold for US$795.

Elsewhere, the electronics chain Radio Shack decided that they should get into the personal computer business. Their Tandy-Radio Shack 80, or TRS-80 (known to some computer hobbyists as a "Trash-80," in the first of many platform flamewars to come) was available in modular form, with the keyboard and computer selling for US$399, the black and white display for US$199, and a cassette storage system for US$49. The main advantage that Radio Shack had over the others was their built-in distribution system. Each of their 3,000 stores was given a single TRS-80 to sell, but within a month the company had over 10,000 orders. The lowly TRS-80 quickly became the top-selling personal computer of the trinity, as new models enhanced its capabilities.

The final computer of the trinity was made by the only company to survive into the modern age as a computer company. The Apple ][ was a refined version of the Apple I motherboard, with added color, memory capacity, eight expansion slots, and an attractive beige case with a built-in brown keyboard. It retailed for US$1,298 with 4k of RAM, or US$1,698 with 16k. Initial sales were sluggish as Apple sold only 600 machines in 1977, mostly due to the high price compared to the PET and TRS-80. However, with the addition of the fast and relatively inexpensive Disk ][ floppy drive accessory, made possible by an ingenious disk controller using only eight chips that Wozniak designed, the Apple ][ sold 7,600 units in the following year and 35,000 in 1979. It was still a distant third compared to the other two machines in the trinity, however.

Apple's response to being in third place involved the genius of Regis McKenna, the former Intel PR executive who had spearheaded "Operation Crush," the predecessor of the "Intel Inside" campaign. McKenna decided that what the company needed was great marketing, so all advertising for the Apple ][ was glossy and rich, and some ads even claimed that the Apple ][ was the "best-selling personal computer." It had nowhere near such status at the time.

What really turned the company around, however, was the release of the first ever "killer app." This was VisiCalc, the original spreadsheet application, which was released in 1979. The author, Dan Bricklin, wrote it for the Apple ][ simply because that machine, borrowed from his publisher Dan Fylstra, was the only one he had available. A combination of great marketing and even better luck propelled the Apple ][ from an also-ran to a serious contender. In 1981 the company sold 210,000 units, leaving the PET in the dust and nearly equaling the TRS-80's numbers.

Personal computer market share
during the "trinity" years