Before Commodore became famous for the Vic-20 and Commodore 64, it was primarily a manufacturer of typewriters and calculators. That changed when Commodore bought MOS Technology in 1976, acquiring the 6502 processor and engineer Chuck Peddle in the process. Peddle persuaded Commodore boss Jack Tramiel that calculators were yesterday's business and that the emerging personal computer market was where the action was.
The result was the Commodore PET, launched in 1977 and one of the famous "1977 Trinity" alongside the Apple II and Radio Shack TRS-80. Unlike many early microcomputers, which looked as though they had escaped from an electronics laboratory halfway through construction, the PET was a complete machine: computer, monitor, keyboard and cassette storage were all built into one enormous steel case. BASIC was built into ROM, so you could switch it on and immediately start programming.
The most distinctive feature of this original PET 2001 is the keyboard. Commodore needed to squeeze a cassette recorder into the front of the case, so the actual keyboard was reduced to a collection of tiny calculator-style keys. These inevitably became known as "chicklet" keys, and typing anything longer than a BASIC program on them quickly explains why later PETs acquired proper keyboards. They look fantastic. They are also absolutely appalling to use.
While the PET never made inroads into British homes, particularly once Sinclair started selling computers for a fraction of the price, they did carve out a niche in businesses, universities and schools. Before Acorn became entrenched in that sector, for many people a PET was their first encounter with a real microcomputer.
The original chicklet-keyboard PET 2001 remains the most recognisable machine in the range. It looks like a computer imagined by somebody making a 1970s television programme about the year 2000, weighs roughly as much as the desk you put it on, and should be prosecuted for crimes against human fingers. It is also where Commodore's journey into personal computing really began. Without the PET there would have been no Vic-20 and, ultimately, no Commodore 64.