Model: HP 67
Type: Programmable scientific calculator with built-in card reader
Picture: HP 67
Batteries: Battery pack
Lifetime: Introduced: 1976
Terminated: 1982
Notes: Whilst the HP 65 defined the programmable calculator, the HP 67 refined it. It has more memory and editing programs is made easier.

There's also a desktop version of this calculator, the HP 97.

When switching from the HP 65 to the HP 67 I had a little trouble. Instead of above the keys, second functions (again, three shift keys) are printed below the keys. For a while I actually thought my calculator was broken. I always perform a little accuracy-test, 1.0000001^(2^27) = 674530.4707... So when you want to know how accurate a calculator is, simply type 1.0000001 and then press x^2 27 times. When I tried this on the HP 67 I used the wrong keys and actually performed 27 arctan operations... Oh well :-) So beware.

My HP 67 was used intensely by its previous owner. This is the very first HP calculator ever I encountered where some of the keys bounce. And I think it has dropped on its bottom right corner (from quite a height I reckon, because HP calculators don't damage easily). Even so, the card reader/writer still works perfectly.

For more information on this beauty please refer to the better sources, like The Museum of HP Calculators (link valid 2022-12-30).


A power adapter.