Programming the Commodore 64 Again: Create a Game Step by Step

A Commodore 64 Project, Documented Step by Step 🕹️

Jens Christian Ingvartsen Thomsen wrote this 2020 guide while re-learning the machine he had programmed in the 1980s. After buying a theC64 Mini and later a C64, he set a New Year’s resolution: build at least one game in C64 BASIC and one in C64 assembly. Programming the Commodore 64 Again follows that resolution from the first experiment to working code.

It is not a dry reference manual. The book carries the tone of a programmer’s notebook: what he tried, which tools helped, where assembly knowledge had to be rebuilt, and how a finished game took shape.

From BASIC to Assembly 💾

The first project is a Tic Tac Toe clone called Ticle Tocle, built in BASIC. Thomsen explains how he moved from editing code in Visual Studio Code and copying it to the VICE emulator to using CBM Prg Studio, where renumbering, sprite design, character-set editing and screen creation could all happen in one place. The book includes a BASIC listing for the game and shows how screen designs can be exported back into BASIC.

Attention then turns to assembly. The later material presents assembler code for CBM Prg Studio first and Kick Assembler later, reflecting the author’s own path between tools and platforms. Readers who have used CBM Prg Studio can follow one route; those working with Kick Assembler can follow the other.

Designing Sprites, Screens, and Characters 🎨

Commodore 64 games are as much about visual building blocks as they are about instructions. The book covers designing sprites for the game, creating screens with the screen editor, and exporting those screens as BASIC code. It also touches on character-set design within that workflow. For readers who want to understand how graphics data and code meet on the C64, these sections show a practical project route rather than abstract theory.

What the Book Covers

• Building a complete BASIC game, including the Ticle Tocle Tic Tac Toe clone
• Using CBM Prg Studio for code editing, renumbering, sprite design, and screen design
• Exporting sprites and screens into BASIC listings
• Working with the VICE emulator during development
• Moving into Commodore 64 assembly language
• Comparing CBM Prg Studio assembler code with Kick Assembler

Who May Find It Useful

The book sits comfortably with readers who already know something about the Commodore 64 or BASIC and want to see a full game project unfold. It can also suit programmers returning to the platform after years away, especially those who remember the excitement of typing listings and watching a machine respond. Complete beginners may find the early BASIC material approachable, while the assembly sections assume a willingness to work through lower-level concepts and tool-specific syntax.

A Personal Record of Learning by Building

Part of the book’s value is its honesty about the process. Thomsen writes as someone relearning assembly, discovering new tools and asking for help online when Kick Assembler behaved differently from CBM Prg Studio. That perspective makes the project feel attainable: not a polished retrospective from an expert who never struggled, but a record of solving problems one step at a time.

Start Your Own C64 Game Project

If you have ever wanted to understand how a Commodore 64 game is assembled from BASIC instructions, sprite data, screen layouts, and machine-level routines, this guide offers a concrete path. Follow the author’s project, compare his choices with your own, and use the code and tool workflows as a starting point for the game you want to build next.