Kenbak-1
The Kenbak-1 is considered by the Computer History Museum and the American Computer Museum to be the world's first "personal computer", invented by John V. Blankenbaker (born 1929) of Kenbak Corporation in 1970, and first sold in early 1971.  Only 50 machines were ever built using  Bud Industries enclosures as its housing. The system first sold for US$750.  Today, only 14 machines are believed to exist worldwide, in the hands of various collectors. Production of the Kenbak-1 stopped in 1973 as Kenbak failed, and was taken over by CTI Education Products, Inc.  CTI rebranded the inventory and renamed it the H5050, though sales remained elusive.

Since the Kenbak-1 was invented before the first microprocessor, the machine didn't have a one-chip CPU but instead was based purely on small-scale integration TTL chips. The 8-bit machine offered 256 bytes of memory, implemented on Intel's type 1404 silicon gate MOS shift registers. The instruction cycle time was 1 microsecond (equivalent to an instruction clock speed of 1 MHz), but actual execution speed averaged below 1000 instructions per second due to architectural constraints such as slow access to serial memory.

The machine was programmed in pure machine code using an array of buttons and switches. Output consisted of a row of lights.

Internally, the Kenbak-1 has a serial computer architecture, processing one bit at a time.

See also
Datapoint 2200, a contemporary machine with alphanumeric screen and keyboard, suitable to run non-trivial application programs.
Mark-8 The Mark-8 was designed by graduate student Jonathan A. Titus and announced as a 'loose kit' in the July 1974 issue of Radio-Electronics magazine.
Altair 8800, a very popular 1975 microcomputer that provided the inspiration for starting Microsoft.

References

External links
KENBAK-1 Computer Article
KENBAK-1 Computer – Official Kenbak-1 website at www.kenbak-1.net
KENBAK-1 Series 2 – Official Kenbak-1 reproduction kit at www.kenbakkit.com
Kenbak-1 Emulator – Online Kenbak-1 Emulator
Kenbak-1 Emulator – Kenbak-1 Emulator download
The Kenbak 1 - The first Personal Computer – At the Computer Museum of Nova Scotia
Kenbak 1 – Images and information at www.vintage-computer.com
Kenbak documentation at bitsavers.org
KENBAK-uino Hardware-based Kenbak-1 Emulator
Recreating the First PC article about KENBAK-uino at hackaday.com
KENBAK-1 Emulator/Trainer, RetroWiki.es  (Invalid, 2015-02-10)
The Kenbak-1 Prototype, Official Kenbak-1 prototype website at www.thefirstpc.com
Early microcomputers
Computer-related introductions in 1971
Serial computers
8-bit computers