Hello David,
While watching your assembler videos, I noticed a precedence issue in the expression evaluator.
XOR should have the same precedence as OR, but has currently the same precedence as + and -
The same goes for the cowgol version of the assembler.
Btw, I would like to thank you for your great content on your youtube channel. As a guy who started with a c64 and 8085 microcontrollers, I find your coding sessions videos both exciting and educational !