TI-58/59 Modules Curiosity

[brouhaha]

The first handheld computer with non-battery-powered nonvolatile in-system-writable semiconductor memory for storage of user data may have been the Psion Organizer in 1984. It used EPROM capsules which were written in the device, but had to be removed to be erased by a separate UV lamp.

There were earlier handhelds that used EPROMs, e.g. The Matsushita/Panasonic/Quasar HHC, but the device did not write the EPROMs, and they were typically only used for canned programs in the same manner as HP-41 and TI-59 ROM modules.

The HP-71B was intended to support EEPROM modules, which are referenced in the IDS. Based on references in HP's bug tracker, apparently there were even prototypes, but they might not have been packaged to physically fit in a normal-sized 71B module.