After trying to implement the digital rain algorithm in 6502 assembly and failing miserably, I decided to try the cc65 toolkit and write some C code.

It takes a while to load but what you are seeing above is a live emulation of the screensaver software.

Once it’s loaded, the following commands are available through the keyboard:

Aamber mode
Bbinary mode
Ddna mode
Ffull charset mode (default)
Ggreen mode (default)
Hhex mode
Llgbtq mode

You can take a look at the source code in my C64 Playground repository on github and download the prg image for your retro emulation enjoyment.

If you run the screensaver on the real thing and send me a video of it, you are my hero.

Speaking of heroes, this was obviously heavily inspired by the xmatrix screensaver by the legendary Jamie Zawinski.

Update 20210524

Here’s a video of the software running on a real C64, courtesy Jordan McGee.