Rob wrote in :
You can do this with an FPGA. That is a programmable VLSI chip that
you program yourself to perform the functions you need. It operates
at logic speed, not at processor speed.
Thanks.

I'll look into it. I suspect my abilities might be constrained to
running my code as currently, on a PC with at least 1 GHz for the 48+ voice
polyphony I'm getting, but Yamaha hadn't got that when they got 16 voices out
of a DX7 so I do at least have a strong incentive to explore.