Divacore: Smuggling 256-color graphics into a CD — Adélaïde Casa

Divacore: Smuggling 256-color graphics into a CD

Aizysse Baga · 80mm mini-CD EP with CD+G and CD+EG

ArtistAizysse Baga<br>Released2026<br>Format80mm mini-CD EP, CD+G and CD+EG, 5 tracks<br>Runtime17:12<br>UPC / EAN9 91043 61604 7<br>ProductionAdélaïde Sokolov and Aizysse Baga<br>Recording StudioTeenage Wasteland (Montréal, QC)<br>PhotographyPiscenis<br>MasteringAntoine Rotondo for Duke Mastering<br>ManufacturingDuplication.com

Tracklist

Neon Sound · with Rita Baga · 3:39 · CBHBN2600001

Nightmare (Divacore Remix) · 3:33 · CBHBN2600002

Game Over · with J4DE · 3:22 · CBHBN2600003

Moonlight · with Kiara · 3:03 · CBHBN2600004

Top Modèle (Divacore Remix) · 3:35 · CBHBN2600005

The record

Aizysse Baga is a talented drag queen from Montréal and a dear friend of mine. Together we recorded and produced Divacore, a five-track EP, in our hometown at the Teenage Wasteland studio, and we had the honour of three guest collaborators joining us on it. To celebrate, we decided to press a promotional item: a mini-CD, the adorable 3-inch (80mm) format that was popular in the 1990s for releasing singles.

What if I told you that our Mini CD contains NO files, that it's a genuinely, certifiably real Audio CD that plays just as happily in your boombox as in your car, and that shows up as exactly that on your computer? And that if you slip it into a compatible machine, like an old video game console, a slideshow appears on your screen? It's all true: depending on the hardware you're using, our EP will display images in either 16 colors or 256 colors while it plays. This is thanks to a fully official extension of the Audio CD called CD Graphics (CD+G), and even its rarer successor: CD Extended Graphics (CD+EG)!! Take a look below:

One frame straight off the disc: 16-color CD+G (left) and 256-color CD+EG (right).

Proof that a technical limitation won't stop queer beauty from prevailing.

Before we dive in, here's the whole trick in one breath: a CD carries a tiny hidden data lane running right next to the music; we filled it with pictures; some machines know how to show them. That's it, that's the magic. The rest of this page explains how, and fair warning, it gets nerdy. Gloriously so.

The hidden lane: subcodes

How is this possible? An Audio CD contains audio encoded as 16-bit, 44.1 kHz PCM. Running right alongside that audio is a separate control stream, the subcode, organized into 75 blocks per second (those blocks are the "frames": on an old CD player's time display, next to the minutes and seconds, there's often a third, faster counter ticking them by). It's tiny: it comes to exactly 8 bits, one single byte per frame, split across eight separate channels named P through W. Two of them handle the everyday business: channel P flags the start of each track, and channel Q carries the running time and track numbers (that very MM:SS:FF readout), plus things like the disc's catalog number. The other six, R through W, were left undefined in the original Audio CD spec: reserved, held at zero, waiting for someone to find a use for them. And at first, almost nobody did. And that's where CD Graphics comes in.

Straight from IEC 60908, clause 17: one subcode byte per frame, and the 98-frame block with its two sync patterns.

1985: six idle channels get a job

The official Red Book standard, the document that lays out how to build and encode an Audio CD, was updated circa 1985 to add a new mode: TV-Graphics, better known as CD+G, aka CD+Graphics. The idea is to take those unused RW subcodes and finally put them to work. Read together, the six R-to-W bits of each frame form one 6-bit symbol. Frames are grouped into blocks of 98 (the block from the figure above), and the first two frames of each block carry sync patterns, which leaves 96 usable symbols per block. At 75 blocks per second, 75 x 96 x 6 works out to 43,200 bits per second: a raw 43.2 kbit/s.

You group those symbols into packs of 24 (a PACK, 144 bits), and four packs into a PACKET (576 bits, which is exactly one subcode block), and that's your data format. The subcode doesn't get the heavy CIRC error correction that shields the audio, but it carries its own lighter armor: a (24, 20) Reed-Solomon code plus eightfold interleaving, with an extra (4, 2) code for the first two symbols of every pack. (When a disc gets burned, the drive itself computes and fills in those parity bytes.) That protection is roughly on par with one of CIRC's two layers. Once you subtract the parity room and the command overhead, the usable graphics payload lands at about 28.8 kbit/s.

Straight from IEC 60908: one PACKET, four PACKs of 24 symbols each.

So where does that 28.8 come from? Take one PACK, those 24 symbols, and look inside: only part of it is your picture. One symbol is the command (the MODE and ITEM that announce "this is TV-Graphics"), one is the instruction (what to actually do: write a font, set a color, scroll the screen), six are for...