[makapuf]

Attiny4 has 32B RAM, 6 pins and 0.5KB of flash ... see the whole product range here (pdf link) http://ww1.microchip.com/downloads/en/DeviceDoc/30010135E.pd...

[JAlexoid]

Why would you need more?

I prefer with PIC, as they offer real time very predictable execution. All instructions have same execution time.