updated build instructions

README.md

@@ -13,12 +13,12 @@ Source Code for [snake](examples/snake.asm)
 2. Change to newly created directory  
    `cd 6502_emulator`
 4. Assemble one of the provided examples under `examples/` using [vasm](http://www.compilers.de/vasm.html) or just use the provided `a.out`  
-   `vasm6502_oldstyle -Fbin -dotdir examples/snake.asm`  
-   This should build an `a.out` file which the emulator can understand.
+   `python build_asm.py examples/snake.asm`  
+   This should build an `a.out` binary which the emulator can understand along with `symbols.dbg` for debugging.
 5. Run the emulator  
-   `cargo run -- a.out`
+   `cargo run -- a.out --assembly-source examples/snake.asm --debug-symbols symbols.dbg`
 6. For an explaination of all possible arguments  
-   `cargo run -- -help`
+   `cargo run -- --help`
 
 ## Usage
 ### Debugging