Family 11 — "more horsepower, when the base hardware isn't enough." Some SNES cartridges carry a coprocessor. These examples boot one, prove it runs, then put it to real work — the branch you reach for late in a project, not on day one.

Three chips — SA-1 and Super FX as boot-then-work pairs, the DSP-1 as a single worked example (it needs no boot: the firmware is already on the chip):

The ladder

Rung	Example	Developer question	Chip
11.1	sa1_hello	How do I boot the SA-1 and hand data back via I-RAM?	SA-1
11.2	sa1_starfield	How do I offload real math to the SA-1?	SA-1
11.3	superfx_hello	How do I boot the GSU and run a hardware test?	SuperFX
11.4	superfx_3d	How do I render 3D with the SuperFX?	SuperFX
11.5	dsp1_cube	How do I offload 3D rotation + perspective to the DSP-1?	DSP-1

Boot first (11.1 / 11.3 — prove the chip is alive and talking), then a real workload (11.2 / 11.4).

The two chips, in one screen

SA-1 — the same 65816 ISA as the main CPU, but at 10.74 MHz and with its own I-RAM ($3000–$37FF) shared with the main CPU. So your SA-1 code is ordinary 65816 assembly; the art is the handshake (who writes what, when) through shared RAM. See the SA-1 tutorial.
SuperFX / GSU — a custom RISC processor for bitmap and 3D work. It has its own ISA (no C compiler — the GSU code is assembly, .sfx sources assembled by wla-superfx), renders into cartridge RAM, and DMAs the result to VRAM. See the SuperFX tutorial.

All three are validated natively by luna, which detects and runs the SA-1, the GSU and the DSP-1 in the headless test harness — no chip-ROM side channel needed. The DSP-1 leg additionally needs Sony's dsp1b.rom firmware installed into luna (copyrighted, not shipped); without it the test SKIPs rather than fails — see dsp1_cube.

DSP-1 Cube SA-1 Hello World SA-1 Save SA-1 Starfield (Murmuration) SuperFX 3D Cube Super FX Game Skeleton SuperFX Hello Super FX Save