I'm currently using a PR3 and it's working fine, at least as a computer/DCC interface (which is what I use if for). I was wondering if a PR4 would be more functional, but when I checked out the specifications, I couldn't find any differences between them. Are there any differences? You'd think a new model would provide some new feature or capability, but I can't seem to find one.
They both have the same functions, but the PR4 is meant to work with 64-bit operating systems (Windows 10/11, MacOS Catalina and later). I used to plug my PR3 into my MacBook pro running MacOS Mavericks, but once I upgraded the OS to a newer version, it failed to work anymore. I currently use my PR3 with a 20 year-old PC running Windows XP.
That's odd, because I programmed most of my locos using a PR3 via Decoder Pro on my MacBook running Big Sur with no issues. It's currently attached to a RasPi 4, with RPi-JMRI installed and it's working fine.
Older PR3s need a firmware update for 64 bit systems. Functionally, I think the PR4 is identical to the PR3 (notice that according to the PR4 manual they take the same driver). I suspect the change was due to a part no longer being available requiring a redesign.
That probably explains it. I've updated the firmware on a few things, I guess this was one of them. I'll just write a 4 over the 3 with a sharpie so I know what I'm dealing with.