Bad Apple C64 ((exclusive)) 〈FULL - 2025〉

The C64 demo treats the video frames not as pictures, but as polygons. It stores a stream of vector coordinates. When the video plays, the CPU is rapidly drawing lines and filling polygons to create the silhouettes on the screen in real-time.

The Oxyron demo utilized a specific set of tricks that are hallmarks of the "Demoscene"—a subculture of programmers dedicated to pushing old hardware past its breaking point.

And yet, there is the shadow. Reimu fires a homing amulet. The screen scrolls. The beat drops. bad apple c64

Porting a high-frame-rate video to a 1 MHz machine with only 64KB of RAM is a nightmare. The original video contains over 6,000 frames. On a standard C64, a single uncompressed frame could take up 8KB or more—meaning the entire video would require dozens of floppy disks. How Onslaught Cracked the Code In 2014, the demo group Bad Apple 64

The Commodore 64 is a legendary machine, but its limitations by modern standards are severe. At its heart sits the MOS Technology 6510 CPU, running at a sluggish 1 MHz (or roughly 0.98 MHz in PAL regions). It possesses 64 kilobytes of RAM—the amount of memory modern computers use to store a single low-resolution icon. The C64 demo treats the video frames not

The internet soon saw "Bad Apple!!" running on everything: scientific calculators, graphing calculators, Arduino microcontrollers, old Game Boys, and even a hard drive actuator. But the Commodore 64 version, released in the late 2010s by the demo group Oxyron, is widely considered the "final boss" of these ports—a masterpiece of optimization that pushed the hardware to its absolute thermal limits.

While the original shadow video is black and white, the C64 version uses the machine’s native luminance. They chose a dark grey (Color $0B) and a bright white (Color $01) on a black background. This reduces color data to zero—each pixel is simply "on" or "off." This allows them to use without wasting bytes on color attributes. The Oxyron demo utilized a specific set of

While the CPU draws the vectors, the computer still needs to access the data for the shapes. This is where the demo utilizes the Commodore 1750 RAM Expansion Unit (REU). The REU adds up to 512KB (or even 2MB in later iterations) of fast RAM to the system.

The demo runs at 12 frames per second (fps) at a 1MHz clock speed—an incredible achievement for hardware from 1982 .

The video featured silhouetted characters from the Touhou Project game series morphing and dancing against a stark white background. The high-contrast, black-and-white aesthetic was visually striking, but more importantly for programmers, it was algorithmically friendly. Because the video consisted mostly of solid black shapes and white backgrounds, it was ripe for compression and porting.