The 4HP eurorack module has a 8-pin DIP socket on the outside like the old Simmons EPROM drums that host an ATtiny85 MCU.
Like an Ardcore or Euroduino it can host whatever you program yourself into an ATtiny85.
Anything from simple VCO’s, LFO’s and other oscillators to complete drum sounds and complex FM voices.
2 analog/CV inputs with attenuators and 1 cv analog/digital input jack.
1 audio output jack.
It is supplied with the necessary library/core interface for writing any DSP application you want with the Arduino IDE and playing it in your eurorack synthesizer.
The dsp-Host is shipping now for $99 and is supplied with a preprogrammed chip for instant playing.