This is a snapshot of the shoddily maintained Pinky Processor repo,
cobbled together to lure Jaymin Kessler.

The instruction set is described in pinky_isa1.txt

The top-level simulator ran last I played with it.

The idea behind the pinky is to have lots of very small, simple processors
with bitwise-addressible memory and a little bit of visible local memory,
no addressible registers, no cache, and 4 instructions, which are focused
on self-modifying code and the idea that they quiesce quickly to a sleep
state while possibly being fully implementable with async logic.

They're meant to be interconnected using a serial bus to lots of other
pinkies, as a single pinky can't get much done alone.

The core operation of a pinky is the move instruction, which is meant
to change data in another move instruction, so that when that next move
instruction runs, it's doing a lookup operation.  The other important
operation is arm, which waits for you to write to an armed address, and
when you do, it executes the specified code as soon as it gets to the next
wait instruction.  The last instruction setN is meant only to change
the dynamic length of the instruction set and its operands, which helps
optimize code around the working set size.