Interesting information about using the GPU of the Raspberry π.
In the forum thread https://stardot.org.uk/forums/viewtopic.php?p=152451#p152451 emulators for 6502 and other processors are discussed, even pdp-11 was mentioned.
More details can be found at https://github.com/hoglet67/PiTubeDirect/wiki
The pdp-11 emulator is in the 'egg-eater-dev' branch.