Uses a Dallas Semiconductor DS89C440 (an Intel 8052-compatible microcontroller) to read data on the Wheelwriter's serial BUS. Commands generated by the Wheelwriter's Function Board when keys are pressed can be displayed as ASCII characters or as a 3 digit hex number.
This project only works on earlier Wheelwriter models, the ones that internally have two circuit boards: the Function Board and the Printer Board (Wheelwriter models 3, 5 and 6).
The MCU connects to the J1P "Feature" connector on the Wheelwriter's Printer Board. See the schematic for details.
Wheelwriter Interface