4kB demo wow

mindblowing considering what I could write on my 1kB ZX81 lol, is it in dos or windows ? does it rely in any way on available windows resources to pull this off ? the framebuffer alone would be bigger than 4kB ? presumeably the instruction to perform the animation is 4kB, cart manufacturers are to blame for muddying the water by popularising kilobit (kb) versus kilobyte (kB) confuses people even now. a kilobit is 1000 bits and a kiloByte is 8000 bits. 8 bits to a byte etc … yawn