Comment 27 for bug 579336

Looking into this at the moment: the very first step for supporting an external assembler is providing an option to load assembled binary/HEX files. Then you could open and run an already assembled file with valid opcodes.

Saving to a HEX file has already been requested previously: https://bugs.launchpad.net/gnusim8085/+bug/579344

So once these two steps have been decoupled (saving and loading HEX files), supporting an external assembler would not be complicated to do, if that's really what people want to do.