Sorry to be so long in reporting back. I have some hardware now which is based on a Microchip microcontroller and USB. I chose USB because most PCs and laptops today have USB ports. I have been reading how Com Ports don't work so well, particularly on laptops, that I thought USB would appeal to more people. Let me know how you feel. Using USB also solves the problem of how to power an IR device as you can draw more than enough power from it whereas with a COM Port one has trouble getting adequate power.
I am programming the assembly code for it and so far I have been able to report IR activity to the PC. My son-in-law is writing code to read the IR activity, as reported to the PC, and also code to support the sequencing of the MX cloning process.
I will be completing the code for the micro-controller to transmit commands and data and also to sequence between transmitting and receiving so that the cloning process will work both ways, i.e to and from the PC.
