There’s one thing most people forget about PlayStation 1 games, that moment the music shifted suddenly when you entered a new room, and the disc in the back just kept spinning, making that weird metallic sound, without the game ever stuttering. Back then, nobody really cared, we just wanted to play, but it was almost a miracle of engineering to get that working in a box with two megabytes of RAM. Two. I take a random photo of my breakfast today and it eats up more memory than the whole console had, yet they still managed to jam footsteps, explosions, raspy voices, and entire orchestral tracks in there without the whole thing exploding. <br>The key to all this was a chip dedicated just for audio, the SPU. I think it had about 512KB of its own memory, which meant the main processor could be focused on drawing polygons and physics while the sound ran alongside in a world of its own, with 24 channels playing at the same time and a built-in reverb effect that gave you that cave-like feeling. But, you know, 512KB is still a pittance if you try to stuff uncompressed audio in there. One second of clean sound would kill it in an instant. <br>They used a compression technique called ADPCM, a version adapted by Sony that instead of storing the sound point by point, only stored the difference from one second to the next. It’s kind of like trying to summarize a story by only telling what changed and ignoring the rest. Was it perfect? No, of course not. You could hear this sort of hiss in the background, a tinny sound you notice right away in the voices and the sound effects. Actually, I noticed the other day on a Bandcamp electronic playlist that people are trying to recreate that exact muffled ADPCM timbre now, which is funny because back then it was just a desperate technical limitation and today it’s become an entire aesthetic, a kind of nostalgia for anyone who grew up playing on a 14-inch tube TV in their bedroom. <br>And then there was the music itself, which in most cases didn't even go into the memory. It played straight off the CD in standard audio format, the same Redbook format of the CDs we bought in stores. In Final Fantasy VII or Symphony of the Night that’s how it worked, the player would read the music while they used a format called CD-XA to interleave the scene data without cutting the sound. That’s why sometimes the music would stutter for a millisecond when you changed screens or when the disc was busy loading data for a boss. <br>The Super Nintendo already used a logic similar to Sony’s chip, the SPC700, but with way fewer channels and no chance of streaming straight from a disc. Actually, going back to that PS1 disc player, it was precisely that reading juggle that made the laser wear out after a few years and forced us to turn the console upside down just to get it to read the scratched discs. <br>When the Dreamcast and PlayStation 2 came along, all that gymnastics stopped being so dramatic because the memory shot up and developers finally had some space to breathe. But we lost a bit of that raw magic of hearing an entire soundtrack coming out of a space where today not even a text document with half a dozen pages fits right.