WriteUp: 16 Bytes of x86 that turn Matrix rain into sound • Hacker News Board

Re: WriteUp: 16 Bytes of x86 that turn Matrix rain into sound

#21

Post by HellMood » Mon, May 18, 2026, 7:39 AM UTC

amenghra wrote: post #19

There are several tiny demos on pouet.net, such as this 32 bytes dragon fractal: https://m.pouet.net/prod.php?which=63522 Very impressive what people can craft in an order of magnitude fewer bytes than this comment!

Oh yes, that was one of my first demoscene productions :)

Actually, just a few days ago, i had the chance to run a modified CGA 8086 version of this on a real old piece of hardware https://youtu.be/XLrjChvJf0k

Re: WriteUp: 16 Bytes of x86 that turn Matrix rain into sound

#22

Post by pjmlp » Mon, May 18, 2026, 7:48 AM UTC

HellMood wrote: post #2

"wake up! 16b" (Outline Demoparty, May 2026, Ommen, NL) is a 16-byte MS-DOS production that uses video memory to calculate a Sierpinski fractal and play it as audio. Video: https://youtu.be/MvycyU-kLjg | Pouet: https://www.pouet.net/prod.php?which=106210 The 16-Byte Code: int 10h ; Init Video Mode 0 mov bh, 0xb8 ; Setup VRAM segment mov ds, bx L: lodsb ; Load [SI] to AL, inc SI sub si, 57 ; Move pointer backward xor…

Great stuff!

Re: WriteUp: 16 Bytes of x86 that turn Matrix rain into sound

#23

Post by HellMood » Mon, May 18, 2026, 7:48 AM UTC

briansm wrote: post #16

For a more laid-back chill 'rain' demo, have a look at "Rainy 32b" 32-byte x86 demo: https://www.pouet.net/prod.php?which=86923 https://www.youtube.com/watch?v=iCgIQuPHb5w

Hey, glad you like this as well. Fun fact, i had a COVOX version which even sounded better, but didnt work sometimes ... so i handed in the "slightly worse" version xD

Re: WriteUp: 16 Bytes of x86 that turn Matrix rain into sound

#24

Post by gsliepen » Mon, May 18, 2026, 7:51 AM UTC

Seems like this does the reverse of the C64 demo "A Mind Is Born" (https://linusakesson.net/scene/a-mind-is-born/): that one is making music first, and simultaneously interprets it as graphics. Of course that C64 demo is huge compared to this x86 one :)

Re: WriteUp: 16 Bytes of x86 that turn Matrix rain into sound

#25

Post by Fnoord » Mon, May 18, 2026, 7:58 AM UTC

briansm wrote: post #16

For a more laid-back chill 'rain' demo, have a look at "Rainy 32b" 32-byte x86 demo: https://www.pouet.net/prod.php?which=86923 https://www.youtube.com/watch?v=iCgIQuPHb5w

Ranked 6th. WriteUp is ranked 2nd. Makes one wonder about the other entries.

Re: WriteUp: 16 Bytes of x86 that turn Matrix rain into sound

#26

Post by HellMood » Mon, May 18, 2026, 7:58 AM UTC

gsliepen wrote: post #24

Seems like this does the reverse of the C64 demo "A Mind Is Born" ( https://linusakesson.net/scene/a-mind-is-born/ ): that one is making music first, and simultaneously interprets it as graphics. Of course that C64 demo is huge compared to this x86 one :)

In that way the title is misleading. My original "m8trix" from 2014 already did smear pseudorandom letters across the screen ( in 8 bytes, then in 7 ) https://www.pouet.net/prod.php?which=63126 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 doesnt really matter, but "16 bytes that turn sierpinski sound into matrix rain" would be true too =)

Re: WriteUp: 16 Bytes of x86 that turn Matrix rain into sound

#27

Post by HellMood » Mon, May 18, 2026, 8:10 AM UTC

Fnoord wrote: post #25

briansm wrote: post #16

For a more laid-back chill 'rain' demo, have a look at "Rainy 32b" 32-byte x86 demo: https://www.pouet.net/prod.php?which=86923 https://www.youtube.com/watch?v=iCgIQuPHb5w

Ranked 6th. WriteUp is ranked 2nd. Makes one wonder about the other entries.

"Rainy" was a 32 bytes production in a (strong!) 256byte competition "Wakeup" was a 16 bytes production in a (strong ^^) 128byte competition

Sometimes, content to size ratio wins. Other times, not so much ;)

Re: WriteUp: 16 Bytes of x86 that turn Matrix rain into sound

#28

Post by userbinator » Mon, May 18, 2026, 8:26 AM UTC

Remarkably, sending this entire mixed-data byte directly to system port 61h, which historically manages various low-level motherboard controls, does not disrupt the system. In standard DOS environments and modern emulators, pushing these extra bits to the port is effectively harmless.

If anyone is curious what the other bits do and how the PC speaker really works:

https://fd.lod.bz/rbil/ports/keyboard/p0060006f.html#table-P...

https://forum.vcfed.org/index.php?threads/pc-speak-technical...

...and I wouldn't be surprised if some chipset put more hazardous functionality in those reserved bits.

Re: WriteUp: 16 Bytes of x86 that turn Matrix rain into sound

#29

Post by ObiKenobi » Mon, May 18, 2026, 8:39 AM UTC

My most favourite demo is "Freespin" which runs entirely on a floppy drive without a computer. Crazy stuff.

https://www.youtube.com/watch?v=zprSxCMlECA

Re: WriteUp: 16 Bytes of x86 that turn Matrix rain into sound

#30

Post by HellMood » Mon, May 18, 2026, 8:40 AM UTC

userbinator wrote: post #28

Remarkably, sending this entire mixed-data byte directly to system port 61h, which historically manages various low-level motherboard controls, does not disrupt the system. In standard DOS environments and modern emulators, pushing these extra bits to the port is effectively harmless. If anyone is curious what the other bits do and how the PC speaker really works: https://fd.lod.bz/rbil/ports/keyboard/p0060006f.html#…

I tested this on a real FreeDos based notebook and it survived ;) But seriously, on more modern systems it doesnt do anything harmful anymore, while i have read that on older systems, you could provoke a system crash this way. Which then would create the interesting task of designing the CA in a way that it "avoids" the hazardous values. For now it seems that "anything goes", at least on all my semi-old and newer systems. DosBox Emulators literally dont care ;)