Does anyone know of a converter to take 8051 assembly source code to C source code.
The conventional reply to this request is: "No. You can't turn back hamburgers into a cow." What you can get, and is sometimes advertised as a decompiler, is a CPU simulator written in C hard-linked to a copy of the machine code. That's equivalent to constructing a statue of a cow from hamburgers. It still wont eat grass and give milk, though.