This was written before I had even heard of "linkers". My fundamental problem was that the Merlin assembler had to hold, in the memory of an Apple 2, both the source and the object, at one time, as this was an in-memory compiler.

However the source was much too large to all fit in memory.

So I broke the source down into logical, and fairly self-contained parts:

Part 1 - tokenization and general utilities

Part 2 - compiler (produces P-codes)

Part 3 - menu, file handling

Part 4 - interpreter (interprets P-codes)

Part 5 - text editor

Part 6 - more of the compiler (processing a 'block')