A 1981 Casio VL-1—once known for its cheap, sturdy design—has been rebuilt with modern electronics. The original sound synthesis hardware was removed, an ESP32-C3 now handles playback using samples from a microSD card, and the original buttons plus an OLED scr
There’s a particular kind of charm in old cheap keyboards: the kind that feel solid in your hands, even if the sounds they make can’t quite do everything you want. In 1981, Casio’s VL-1 leaned into that bargain reality—robust build, but a limited sound palette.
That’s exactly what [Max Vega] started with. Rather than treat the VL-1 as something to outgrow, he rethought what its “center” should be. The original electronics of the VL-1 were largely surplus to requirements for this rebuild. The original interface and speaker stayed in place, but most of the monophonic sound synthesis hardware came out.
In its place, [Max] enlisted an ESP32-C3 to run the show. The result is a ROMpler—turning the VL-1 from a synth that generates sound into an instrument that relies on hardcoded sample playback. Samples live on a microSD card, which the ESP32 reads to load sounds. The point is straightforward: microSD provides an enormous amount of storage. making it easier to keep lots of different sound packs available.
To keep the experience friendly, [Max] built instrument selection around the VL-1’s existing control scheme. The original buttons still do the heavy lifting. and an OLED screen provides the extra information you need to navigate between instruments. You play the instrument the same way as before using the simple keyboard. but the rebuild gives it a much larger sonic menu.
The fun doesn’t stop at swapping sounds. [Max] also implemented extra modes that let you play chords at a single touch, adding a little performance flexibility without changing how quickly you can get notes out.
If the idea is a versatile keyboard that can fit in a backpack. this kind of conversion lands in the sweet spot: keep the classic hardware that feels right. modernize what matters for sound storage and playback. The broader vibe will be familiar to anyone who’s followed Casio keyboard hacks before—this isn’t the first time someone’s taken the VL-1 and pushed it into new territory. But this specific upgrade—ESP32-C3. microSD-loaded sample packs. OLED-assisted selection. and one-touch chord modes—makes the old unit feel newly useful rather than just repurposed.
Video is available after the break.
Casio VL-1 ESP32-C3 ROMpler microSD keyboard hack OLED screen sound packs retro electronics
Why would you hack a 1981 Casio tho, just buy a new keyboard?
So they took out the original sound stuff and now it’s basically a sample player? Kinda cool but also kinda pointless? Like I’m not sure how it sounds compared to the original if it’s all from a microSD.
Wait OLED screen means it has internet now right? Like you can download sounds from WiFi or something? Because otherwise why put a screen on it… unless it’s for tracking chords or whatever.
This is the most “throwback but with extra steps” thing ever. I don’t even know what an ESP32-C3 is but I’m guessing it’s like a little brain that reads SD cards. Also one-touch chords?? back in my day you had to press stuff correctly and suffer. I hope it still feels like the original keyboard though, because that part is the whole point.