I'd like to add a few comments (memory permitting):
1) Their official name since 1938, was Asahi Optical Company - the Pentax was the name of one of their first models, and is now the name by which they are known. An older name is Asahiflex, the flex referring to the flip-up mirror.
2) They initally made lenses for Minolta, Konica and others before making their own cameras.
3) AOC developed the pentaprism for the viewfinder - hence the name Pentax. This spelled the beginning of the end for rangefinder cameras.
4) AOC also came up with TTL metering. The Spotmatic (1964) was ground-breaking as I recall. Since I was a university student, and had just bought an SV (with the clip-on meter) to replace my model S (with the manual stop-down diaphragm), the Spotmatic was not in my budget.
5) Their lenses were among the world's best. And one never heard of the term "bad copy" in reference to their bodies/lenses.
6) Canon was a relatively minor player until the A series came out (A-1 and AE-1).
If I was looking for my first DSLR, I would seriously consider them.