AI Without Microcontroller?

Would it be possible to create an AI system without using a microcontroller?

Build neural net with transistors

Could be a lot of work but build it with transistors, no CPU needed. Until now neural nets are only simulated within computer software.

Neural nets have been

Neural nets have been simulated with hardware: http://csis.pace.edu/~ctappert/srd2011/rosenblatt-contributions.htm