For $395, you got your Altair in kit form, bags and bags of pieces and a stack or 3-ring binders full of instructions on its assembly. You had to be organized, patient, and good with a soldering iron. It was not easy. Most kits were never completed, and of those that were, many didn’t work.

Electronics kits had been around for a while, becoming especially popular in the ’60s, a time when transistors and other electronic components were finally cheap enough for the hobbyist to buy. If you knew your stuff you could design your own amplifier; if not, you could buy a Heathkit, which included all the parts and excellent instructions for putting them together. There was, however, a vast difference between an amplifier and a computer.

A few hobbyists were lucky enough to work with the big mainframe computers; the rest had never seen one or at most had gazed in awe through the doors of a clean, bright computer room full of humming machines and tape drives spinning and stepping through reels of mysterious data. You could almost smell the power.

In theory, you could build your own computer. The pieces were all there, particularly inexpensive transistors, but the numbers needed made this a daunting prospect. A few brave hobbyists attempted homebrewed computers using discrete components and patched-together plans from textbooks and maintenance manuals. Such projects nearly always ended in frustration when the dream ran up against the reality of just how complicated a computer really is.

Instead, hobbyists had to content themselves with making simple versions of computer components such as flip-flop boards and digital counters, knowing that their creations were distant relatives of the real thing. There was a bit of magic involved, the same magic known to kids who in those days might have lovingly assembled models of WWII bombers. It brought you closer to the mystery.

Is it any wonder, then, that these hobbyists greeted the Altair with such enthusiasm? The kit computer was made possible by a new development in electronics, the microprocessor, which consolidated the most complex circuits of the computer into a single chip. Assembly was still a huge, complicated task, but now it was at least possible, and when you were done you had something you had only dreamed of, a computer of your own.