Please start by telling us the device you are interested in generating codes for. This will determine which IRP file you should edit. John has been gracious enough to supply IRP files for NEC protocol and all Sony Protocols.
Presumably, you've downloaded and extracted file from the zip for MakeHex? If you have not, please do so and see the readme, looking at it side-by side in notepad.exe with an existing .irp file (pick any one you'd like).
Then, let us know what device you are wanting to generate codes for. If you are unsure, post a sample learned code and we can point you in the right direction.
Please don't take offense as I'm not purposely trying to be a hard-ass or speak down to you here as this program is really, really technical. This stuff is just plain hard to grasp unless you've done signal processing or other fields such as telecom, etc.
Even I had some difficulty first time around. I still ping JArmstrong and John every now and then. In fact, we are working to decode my IR keyboard's mouse functions. It is not always easy.
A good place to start for background info would be the Pronto (not Pronto NG) faq where discrete codes are discussed. The FAQ talks about device IDs and function(command)s. That is exactly what Makehex does: Generate Pronto friendly IR code data conforming to a specific IR protocol and containing data to address a particular device ID and send a specific command.
IRP file contents.
There is typically an individual .IRP (IR Protocol) file for specific protocol. You will see Sony15.irp, Sony12.irp etc. These are variations of a sony IR Protocol used by different Sony devices. (12 bit, 15 bit). Hopefully, the light bulb just came on. Inside these files are placeholders to specify the Device ID and a range of Functions to generate. That's why it will help to open files side-by-side so you can get the bigger picture.
To reiterate...
To know which .IRP you need to use, we need to know the Manufacturer and Type of device. Then, using well known sources on John's website, especially for all Sony devices, we can tell you what values you need to plug in for Device and Function to generate a full codeset of Pronto-Friendly IR code data.
I hope this sheds some light on this rather deep subject.
And...
You never thought you'd be in this deep when you paid that money for the Pronto, did ya?
It is an addiction. Once you get this thing setup to do what you want, you'll never ever use an OEM remote again.
