If you’re diving into C64 Assembly Programming, Episode 2 from TheStuffMade YouTube channel is a goldmine of practical techniques. Focused on 6502 assembly for the Commodore 64, this episode walks you through smarter string handling, macro creation, and how to debug your code effectively. Whether you’re just getting started or refining your low-level skills, here are seven key takeaways.
1. Null-Terminated Strings Are Your Friend
Instead of hardcoding string lengths, use zero-terminated (a.k.a. C-style) strings. This simplifies loops and makes your code adaptable.
2. Code Flexibility with Self-Modifying Techniques
Want to place strings at different screen locations? The episode shows how to modify code in memory while it runs—a staple in 8-bit development.
3. Reusability Through Macros
Replace long repetitive routines with custom macros. Define parameters like string and screen position for cleaner and scalable code.
4. Debug Like a Pro with CBM prg Studio
Learn how to step through instructions, monitor CPU registers, and inspect memory using the built-in debugger. It’s not full C64 emulation, but it’s still powerful.
5. Mind the Macro Label Trap
Defining local labels inside macros avoids conflicts. Use the @ symbol to keep labels scoped and prevent assembler errors.
6. CPU Cycle Counting for Optimization
The debugger provides live CPU cycle counts. Perfect for squeezing out performance or learning how efficient (or inefficient) your loops are.
7. Visualizing Output Without a VIC-II
Even without full video chip emulation, CBM prg Studio simulates screen RAM, letting you verify string placement while debugging.
For anyone serious about C64 Assembly Programming, this episode breaks down complex topics with clear examples. It balances theory with hands-on tips, helping you write better, more flexible 6502 code—and maybe even enjoy it.
Watch the full episode and download the project files to start experimenting.
