xbbasm: The seX-Bob-omB X-Assembler!

A cross-assembler targeting the 6502/6510 processor. Mainly written for learning purposes and to assist me in my experiments with assembly language programming for the Commodore 64. Its syntax, although very limited, borrows a bit from Merlin and from the C64 Macro Assembler Development System.

Usage

Basic usage is extremely simple, just run:

$ ./xbbasm program.asm

Optionally specify an output with:

$ ./xbbasm -out b.prg program.asm

For maximum convenience (!) put the binary into your local ~/bin and make sure it's in your PATH.

Features

Some cool things you can do with it (a.k.a. Do-s and Don't-s):

• Use LISP style S-Expressions in operands like:

lda [+ color $27]
ldy [- color 1],x

• Use include syntax anywhere in your file like:

./include screen.asm

{... some code ...}

./include subs/math.asm

{... some more code ...}

./include ../misc.asm

• Insert binary files with ./bin {filename}

• Inline or off-line labels, just take into account that labels not on the same line need to end with :. For labels on the same line that is optional.

• It is allowed to enter label aliases (EQU in Merlin) between an off-line label and the next code line (see examples). This helps to put those below the subroutine name label but above the code and give it a more function-like look.

• For opcodes and operands syntax is case-insensitive.

Notes

About the examples:

Example asm source files in the /examples directory were taken from different sources, credited when relevant, mostly to show what it can be done.

A note on building from sources:

For keeping the directory structure of the project, if you're using the default workspace in $HOME/go in Linux you can create a symbolic link like:

$ ln -s /home/you/path/to/xbbasm/src/ /home/you/go/src/xbbasm

To-Dos:

• Document all the supported syntax so a user doesn't have to go through the sources to figure things not in the examples.
• Add more unit tests since at the moment only the most basic ones exist (no tests for expected errors for example).
• Would be nice to extend the ./bin instruction to support offset and length params ACME style.