My hardware has little modules, which contain a transistor, a resistor, an LED, and two jumpers (for deactivation and testing). There is one module per PL board. The PL boards and COR are active low, although one may change that in the source code. The clock is 8 MHz, and the source code is written in assembly language for speed, although I do have Hi-Tech C source also.
The total cost for a new Controller Aide with five boards would be about $370. You may download the source code at http://www.qsl.net/n1yew.
Written and documented by Andy N1YEW