It is more than 10 years I worked with an Archmedes, and I used the Basic (btw. interpreted but incredibly fast) but not the assembler in it, so maybe I don't recall it completely right, but it wentlike this: the running program had to reserve a piece of memory for the asm result first, simplydeclaring an array using DIM (the name of such declared array was then the reference to the code). Then it had to come across the assembly code (enclosed in some tags). It had to pass the code twice, so it had to be enclosed in a FOR..TO..NEXT cycle. Then you could run the result. The code could include OS calls and maybe references to already declared/used variables.

However, the Archimedes was closer to a PC than to a microcontoller - this approach is not quite trivial. And I would not expect such amount of "luxury" in a resident debugger/monitor...

Jan Waclawek