Hewlett Packard HP-75C - first HP portable computer! - Computer

The HP-75C was HP's first portable computer. It ran on BASIC and had 16 KB of RAM with an expansion port for additional RAM and 48 KB of ROM with three ROM expansion ports. It had a keyboard large enough to type blind on (about 95% of a full-size keyboard), a highly legible alphanumeric display with one line, and an HP-IL port that allowed it to be connected to almost anything.

The HP-75's filesystem made it possible to store multiple files in ROM, RAM, magnetic cards, or tape drives. All basic filesystem commands such as copy and rename were present.

In addition to BASIC, the HP-75 had a scheduling mode with alarms and could save/edit text files. This makes the HP-75 one of the first organizers. The alarms even came in 10 different styles, including: "A short beep", "A series of high, continuous tones" and "A sequence of eight siren sounds".

Card Reader
The HP-75 used a card reader with manually fed cards rather than the motor-driven cards of earlier calculators. These cards were preformatted with clocking information, allowing a fairly wide variation in "pull speeds". (Although mine has become quite fussy with age.) Each card had two tracks and each track held 650 bytes. A lot of data compared to the HP-65, but quite little compared to the HP-75's memory space.

Options included a CRT monitor, small thermal printers and large impact printers, a modem, a plotter, a tape drive, and almost anything that could be connected to HP-IL.

There are 3 modules included: Visicalc, Math & HP75 I/O, as well as various layouts and the bag!

Not tested, no power supply or battery!