It does seem to run things. video with no sound from 2023 of pico-xt (pico-286 was based on it) https://www.youtube.com/watch?v=9F0lXviwLE8 and one review from 2024 https://habr-com.translate.goog/ru/articles/842292/?_x_tr_sl... with actual useful info:
-performance ~8MHz 286 on rp2040
-“VGA and EGA modes on pico-xt are supported to a very limited extent (there is little memory in the microcontroller) and 90% of games will not work in them” but that was 2 years ago
-Prince of Persia and Monkey Island run
-“King’s Bounty just doesn’t start”
Getting "some things" to run is 0.001% of work of writing an emulator. Reaching "50% of the software corpus for the system" is 1% if the work, reaching "90% of the software corpus" is 10% of the work, reaching "99% of the software corpus" is 20% of the work, and so on...
The long tail is long, and for older, more esoteric systems, it is veeeeeeeeery long. You'd be surprised how far a 286 emulator will get with broken implementation of carry out sometimes.
Source: wrote more emulators than I can count