Freespin
Why Hacker News recommends it
Shared as a favorite example of retrocomputing hackery, a demo that runs entirely on a disk drive.
What it is
Freespin is a demo that runs on a Commodore 1541 floppy drive. It makes sound by vibrating the drive head and video by toggling the serial bus lines, and it keeps running after the C64 that booted it is disconnected.
Recommended by 1 HN commenters across 1 different months, 2021 to 2026.
What Hacker News said
Strong rec ObiKenobi · 2026-05 · on “WriteUp: 16 Bytes of x86 that turn Matrix rain into sound”
My most favourite demo is "Freespin" which runs entirely on a floppy drive without a computer. Crazy stuff. [this video]
Cites cbm-vic-20 · 2021-10 · on “The 100 MHz 6502”
Here's a demo running directly on the 1541 disk drive. It generates video by hacking the serial cable that's usually used to connect to the computer, and audio from the drive motors. [this video]
Cites einr · 2022-06 · on “The Floppotron 3.0”
See also: [LINK] -- [this video] A demo, including music and graphics, written for the 1541 disk drive -- no, it is not a C64 demo, it runs entirely on the 1541 (which has a 6502 CPU and some amount of RAM in it)
Cites thristian · 2023-07 · on “MartyPC, cycle accurate IBM PC/XT emulator”
The "C64" demo "Freespin" wires the drive's data cable directly into the monitor's data cable to play a demo (including audio!) without an actual C64 involved at all: [this video]
Cites rzzzt · 2023-12 · on “The 8-Bit Era: Eight Iconic Processor Designs – By Babbage”
There's a demo that plays entirely out of the 1541, you can disconnect the rest of the computer: [this video]