1971 Kenbak-1
The Kenbak-1 is considered the world’s first personal computer. The design was the work of John Blankenbaker of Kenbak Corporation in 1970, and the first sale took place in early 1971. At the time, the system cost US$750. In 1973, Kenbak Corporation closed its doors and production of the Kenbak -1 has been interrupted.
Since the Kenbak-1 was invented before the first microprocessor, it did not have the CPU on a single chip, but was based on several distinct ICs of TTL logic. It was an 8-bit machine and had only 256 bytes of RAM memory. The machine instruction cycle was 1 microsecond (equivalent to a clock frequency of 1 Mhz).
Kenbak-1 programming was done directly in machine code, adjusting various buttons and switches. To keep the cost as low as possible, the output consisted of a series of eight flashing lights on the front panel. There was a slot in the upper right part of the panel, designed to house a card reader, but this was never developed.
| NAME | Kenbak-1 |
| MANUFACTURER | Kenbak Computer Company |
| ORIGIN | U.S.A. |
| YEAR | 1971 |
| END OF PRODUCTION | 1973 |
| BUILT IN SOFTWARE / GAMES | None |
| CONTROLLERS | Front panel keys only |
| CPU | None – TTL based logic |
| SPEED | approx 1 MHz |
| RAM | 256 bytes of shift-register memory |
| TEXT MODES | None |
| GRAPHIC MODES | None |
| COLORS | None |
| SOUND | None |
| SIZE / WEIGHT | 18 |
| I/O PORTS | None |
| POWER SUPPLY | Linear |
| PRICE | $750 new |
Filed under: 70s Computers - @ January 30, 2022 7:49 PM