Long before the invention of Bluetooth or WiFi the "Red Eye" protocol was used by many HP calculators to drive a small wireless printer via infra red signals.
Having an independent receiver for the signals sent by the calculators allows to "print" to a computer to store program listings. It is also possible to use a printer emulator to capture the data and display a virtual printout (including screen dumps).
|HP-IR Receiver with Arduino.pdf||
This document describes the "Red Eye" protocol and explains how to build a receiver which can be connected via a serial or USB interface to your PC.
The hardware is based on the Arduino platform so that no PCB has to be manufactured.
The HP 82240B printer.