Video computer terminal with detachable intelligent keyboard module

摘要

An interchangeable keyboard application module is connected to a video monitor module in a computer terminal to provide sequences of processor instructions and a keyboard for performing a plurality of selectable applications. The video monitor module includes a CRT display, a serial I/O interface and a processor that processes characters received through the serial I/O interface for display on the CRT screen whether or not the application module is attached. The processor in the video monitor module detects the connection of the application module, and then selects its instructions from a memory in the application module first, to prompt the selection of a mode of operation for the terminal, and second to execute the selected mode of operation. The application module uses a plurality of keyboard overlays, each corresponding to a respective mode of operation. In a specific embodiment two of the modes of operation are programming applications related to programmable controllers.