Comment by corysama

Hey! I can speak here.

Back in the day, I wrote a simulator for the PS2’s vector units because Sony did not furnish any debugger for them. A month after I got it working, a Sony 2nd party studio made their VU debugger available to everyone… Anyway…

The good news is that the VU processors are actually quite simple as far as processors go. Powerful. Complicated to use. But, not complicated to specify.

This is made much simpler by the fact that the only documentation Sony provided was written by the Japanese hardware engineers. It laid out the bit-by-bit details of the instruction set. And, the bitwise inputs, outputs, delays and side effects of each instruction.

No guidance on how to use it. But, awesome docs for writing a simulator (or recompiler).