HP-65

The HP-65 was a stunning calculator. Just 18 months after introducing the first pocket calculator with transcendental functions, HP introduced a pocket calculator that was programmable with a magnetic card reader/writer. The HP Journal introduced it as "The Personal Computer" long before that term had become common. At the time, if people had any access to a computer it was probably via a keypunch machine. To this day, the HP-65 is impressive - even to HP 48 users.