Tom03903 wrote:
I guess I don't understand. Isn't OS-10 -- OS-10? Are you saying OS-10, 14 has made changes my computer can't run?
Yes. Your Mac can non longer support run newer macOS versions.
OSx or macOS 10.x is an ever growing series of operating system versions. Each has changes and added features.
So that's like (in the PC world) saying is your computer running system 7 or system 10.
Correct.
10.13 vs 10.14 and 10.15. That's like Windows 7, 8 and 10.
Starting with 10.14 Mojave, the operating system, requires hardware your Mac does not have, and cannot have installed. More specifically a Metal capable video card, which cannot be installed in your Mac.