Well, it's been a good run. I had to put a new video card in my Mac Pro a while back (mid 2010) to run Mojave. It needed a card that supported METAL, so I managed to find an EVGA reference card (GTX 680) that could be flashed with the Mac firmware to give me the boot screen. I figured that future support at that point was going to be short; the writing was on the wall essentially. So, it should really come as no surprise that Catalina won't officially support this old girl. She's had a few upgrades (SSD, newer CPU, more RAM) over the years and it technically is capable of running the OS, and I could get it on with a modification but I don't think I'm going to bother. Am considering swapping it out for Linux at some point once Mojave stops getting updates, or maybe sooner depending on my mood.