The Overlay64 module allows superimposing predefined texts onto an existing analog video signal, depending on the states of up to 24 digital input lines.
Among other possible applications the overlay64 can be used to display the state of various hardware extensions build into a classic home computer directly on the screen:
Installed in a C64 to display the state of a stereo SID board and a Multirom adapter
The user writes a simple configuration file that determines which texts are to be displayed for which input line states as well as which lines control the display. The configuration file is converted to a binary format and flashed to the eeprom memory of the microcontroller using the supplied commandline utility, supported under Linux, MacOSX and Windows.