Kenbak-1

[11] Since the Kenbak-1 was invented before the first microprocessor, the machine did not have a one-chip CPU but was instead based purely on small-scale integration TTL chips.

[12] The 8-bit machine offered 256 bytes of memory,[13] implemented on Intel's type 1404A silicon gate MOS shift registers.

It was designed and invented by John Blankenbaker of Kenbak Corporation in 1970, and was first sold in early 1971.

Unlike a modern personal computer, the Kenbak-1 was built of small-scale integrated circuits, and did not use a microprocessor.

256 bytes of memory, 8 bit word size, and I/O limited to switches and lights on the front panel are also characteristics of the 1975 Altair 8800, whose fate was diametrically opposed to that of the Kenbak.

If the Kenbak-1 were advertised better, and the machine had at least one serial port to make it more useful, it may have done very well at its price-point of $750 in 1971, which no other Turing-complete computer on the market came close to.

A program running in a Kenbak-1 IDE/emulator. Click to start animation. Note that the program's sole use is to show lights being shifted.
Kenbakuino, an Arduino -based Kenbak-1 emulator