[summa_tech]

I don't think I've seen anything sufficiently RAM-like. The classic sense amplifier architecture tends to make this impractical. I guess modern Flash can store a few levels but that's a far cry from actual analog storage.

For a while, you could get things like bucket-brigade CCDs for analog signals (used for reverbs and suchlike). They're still made in small quantities, I think, by boutique operations like Xvive.

Also, there was the ISD ChipCorder, which was actual analog Flash. (Current devices are digital, but the old ones were for a while sold as "MLS ChipCorder" by Nuvoton.)