The HP-75C was the first pocket computer ever produced by HP who wanted a pocket book format for computer as powerful as a desktop. It can also be considered as the first organizer able to deal with multiple alarms, time schedule, real time control of peripheral devices and to memorize text files.

Its 48KB ROM contained a very complete Basic language and a light version of the spreadsheet VisiCalc. Three slots allowed adding pre-programmed ROM modules (Math, finance, word processor).

HP-75 had an integrated a card reader. The cards were manually slipped in front of the magnetic head. Each card was capable of holding up to 1.3 KB of information on 2 tracks (650 bytes each). The card information coding allowed great variations of the reading speed, due to manual handling.

The HP-IL (Interface Loop) interface allowed connecting as many as 30 peripheral devices simultaneously to one computer. Amid the peripherals, one could find a display unit, printers, modems, tape recorder and other devices. As always with HP, the manuals were very complete and pedagogical.

The HP-75D was released two years later. It added a wand and wand port. When used with the Bar Code ROM, the computer could scan CODE11, CODE39, UPC, and EAN codes. This made the computer useful for inventory control.