Wake up! 16b

Released at the Outline Demoparty in May 2026, Ommen, NL

An exploration of algorithmic density in 16 bytes of x86 assembly.

Hey everyone. I learned programming as a kid on an old IBM PC with a monochrome green monitor over 30 years ago and always wanted to create a program for this system. I created well over 100 tiny intros in the last 15 years. Recently I was not too active but the fantastic "Rainbow Surf" from Plex in just 16 bytes motivated me to dig up some old dusty sketches again and get to work.

The creation of this program happened with the usual tinkering around. I was messing with cellular automaton for graphics and sounds and discovering sizecoding tricks. Actually: a) polymorphic asm instructions, like add [bx+si],al

which is 0x0000

b) jumping into the middle of instructions to save bytes and reuse opcodes. In hundreds of tiny experiments, this one stuck out, just by the sound of it.

When I unfolded what's left and removed "the rest", I had a hard time to grasp what's really going on. I was scratching my head looking at the simple formula that remained after golfing many bytes away. I myself didn't expect that the explanation would go this deep for just these few bytes xD.

My original "M8trix" from 2014 already did smear pseudorandom letters across the screen (in 8 bytes, then in 7) and I always wondered how I could make it "sound good". But chronologically in the development of "wakeup", the sound was first. Since you "see what you hear" it doesn't really matter, but "16 bytes that turn Sierpinski sound into Matrix rain" would be a good subtitle =)

So, here are the 16 bytes of x86 real-mode DOS assembly. When you run it, it uses the video memory as a calculation space to draw an infinite Sierpinski fractal, and at the same time bangs the speaker with that geometry.

int 10h ; 2 bytes
mov bh, 0xb8 ; 2 bytes
mov ds, bx ; 2 bytes
L:
lodsb ; 1 byte
sub si, byte 57 ; 3 bytes
xor [si], al ; 2 bytes
out 61h, al ; 2 bytes
jmp short L ; 2 bytes

The code starts with a standard BIOS interrupt: int 10h

. This sets up video mode 0, giving a 40x25 text mode grid. Then the data segment (ds

) is pointed to 0xb800

, the memory address of the VGA/CGA text buffer.

When the BIOS clears the screen, it doesn't fill memory with absolute zeroes. Every character space is two bytes: the ASCII character and the color attribute. All 2,000 slots are set to ** 0x20** (space) and

0x07

The intertwine, the synesthesia goes far beyond w