codec

CODEC remembers everything you play into IN L, but it doesn't record it. It keeps a sketch: the pitch, and the rough shape of the sound, a hundred times a second. That's about 2 KB a second, so it keeps hours of it, in flash, and it's still there after the power's been off.

Each thing you play is filed on the channel FREQ is tuned to. Go quiet for as long as WAIT says and the ghost answers on that channel. It rebuilds what it remembers in its own voice, breath and buzz pushed through the shape of yours, and sends it back over the radio. It's never the recording. Every retelling is saved over what it told, a little worse: smeared, drifting in pitch, more breath than voice. ROT says how fast. In the end you recognise the phrase without hearing it.

It's half-duplex, like a real radio: one side talks at a time. Turn WAIT below noon and the ghost stops waiting and talks over you. Both sides keyed at once is doubling: both voices chopped, and a squeal.

Patch IN R and the right side is a second input instead of the ghost. Then CODEC is a plain two-way radio: two sources taking turns on one channel.

The top of the panel is lit from behind. Its windows are bare FR4, with no copper or mask on either side, over 76 RGB LEDs, each window in its own cell of a black printed baffle.

The two faces are printed on the back of the panel, in copper under black mask, as a line screen. With the module off they're black behind the glass against the black baffle: two blank screens. When a side talks, its window lights and the face comes up out of the light. Hers is your side. The ghost is her own skeleton, in her T-shirt and headset.