HP-75

The HP-75C and HP-75D were hand-held computers programmable in BASIC, made by Hewlett-Packard from 1982 to 1986.

The HP-75 had a single-line liquid crystal display, 48 KiB system ROM
and 16 KiB RAM, a comparatively large keyboard (albeit without a
separate numeric pad), a manually operated magnetic card reader (2×650
bytes per card), 4 ports for memory expansion (1 for RAM and 3 for ROM
modules), and an HP-IL interface that could be used to connect printers,
storage and electronic test equipment. The BASIC interpreter also acted
as a primitive operating system, providing file handling capabilities
for program storage using RAM, cards, or cassettes/diskettes (via
HP-IL). 


The HP-75D (1984–1986) added a port for a bar code wand, often used for
inventory control tasks.