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
Interface connection to J1P "Feature" Connector in the Wheelwriter Printer Board