I love these fantasy computers. This one looks very similar to Pico-8, which I've made a couple of games for. I wonder how TIC-80 compares to it. One obvious thing is that it's open source, which is very cool. From a quick search, Pico-8 seems to have a larger community though.
Perhaps my favorite fantasy console is one of the first, if not the first to exist: CHIP-8. It was originally an easy way to program video games for the Cosmac VIP hobbyist computer, but it found new life in recent years because writing a CHIP-8 interpreter is a good "babby's first emulator" exercise. It's not really capable of much by today's standards, but it goes to show that the fantasy console phenomenon has a long and deep history.
Yes, you can write code in a separate file and then import it to cartridge with tic-80 console commands[1]
You don't have to do this manually every time, just make a shell script with multiple commands; e.g. this will import code, save and run the cartridge:
./tic80 --skip --fs="$PWD" --cmd="load cart.tic & import code main.lua & save & run
The other way is indeed to buy or build yourself a PRO version, it can work with cartridges in plaintext format.
