[cmrdporcupine]

Assembler isn't hard to write.

It's just bloody hard to read, unless you wrote it, and wrote it recently. You effectively have to have the state of the register set in your mind the whole time.

Lots of C code from back then is just as impenetrable though. It has structure but it's terse and mechanical. Everyone rolling their own lists and hash tables and string functions in every program, lots of unrolled loops, etc. Different constraints. Memory & CPU was expensive.