2024/Moniterm monitor support

[jesup]

It would be cool to have A2024/Moniterm monitor support; which would allow much higher resolution displays (~1K x 800 ish, at 10 or 15 hz).

Speaking as someone who has both A2024 and Moniterms :-) When I imaged one of my drives, I had to delete envarc:system/screedmode.prefs and reboot to use it. (You can kinda use it in 2024 mode, but it's a nasty experience today)