3 ms·

In terms of 3D SNES graphics, the few later games that did support 3D graphics (e.g. Starfox) had an "enhancement chip" built into the game cart that allowed fo

In terms of 3D SNES graphics, the few later games that did support 3D graphics (e.g. Starfox) had an "enhancement chip" built into the game cart that allowed for it. And by "enhancement" I mean the SuperFX chip basically ran the game and the SNES just provided power and A/V out.

seeekr 10y ago
How was it economically viable to, iiuc, basically include computational power comparable to that of a full console, inside every single game cartridge? That sounds ludicrous! (Starfox on SNES was an excellent game, enjoyed it very much!)
- gambiting 10y ago
  Well, the CPU they added was probably far less than $1/each when bought in bulk, so if you were making a PCB with chips on it already, you might as well add an extra processing unit.
- tinus_hn 10y ago
  For one thing, it's the ultimate form of copy protection.
  - planteen 10y ago
    But most cartridges used the same design. So if you had one SuperFX cartridge, you could put it in your copiers cartridge slot and then play all the others.
    - b409ba0801cd21 10y ago
      That was true of the DSP-1, but not true of the SuperFX or SA1. The DSP-1 was a preprogrammed microcontroller that preformed certain calculations that would have been inefficient to preform on the SNES CPU. The inputs were written to a memory mapped location, and the outputs read back. An interposed copier could simply redirect these reads and writes. The SuperFX and SA1 used the cartridge's ROM and RAM for program and data, and therefore these enhancement chips are placed between the SNES bus and the cartridge memory. The cartridge memory is unavailable to the SNES bus while the enhancement chip is executing, as in the SuperFX, or the the enhancement chip enters wait states while the CPU is accessing the cartridge memory, as in the SA1.
      - planteen 10y ago
        Ah gotcha. My memory is getting hazy. I had a floppy disk copier many years ago and remember using Mario Kart to play other games. I thought it was SuperFX but I was wrong.
pcwalton 10y ago
> And by "enhancement" I mean the SuperFX chip basically ran the game and the SNES just provided power and A/V out. Sorta—there was no direct video out from the cartridge on the SNES (though oddly enough, there were audio out pins), so the Super FX chip had to actually generate sprites on the fly for the PPU to composite together. This resulted in unfortunate color limitations. You can see in the debug info for Star Fox 2 that the dynamically allocated sprite count was something that they had to constantly keep track of: https://r.mprd.se/fup/up/35454-Star_Fox_2_(Japan)_(Proto)_(Alt_1)_[En_by_Aeon_Genesis_v1.0]_(Debug_Version)-1460132615.png https://r.mprd.se/fup/up/35454-Star_Fox_2_(Japan)_(Proto)_(A...

seeekr 10y ago

How was it economically viable to, iiuc, basically include computational power comparable to that of a full console, inside every single game cartridge? That sounds ludicrous! (Starfox on SNES was an excellent game, enjoyed it very much!)

gambiting 10y ago
Well, the CPU they added was probably far less than $1/each when bought in bulk, so if you were making a PCB with chips on it already, you might as well add an extra processing unit.
tinus_hn 10y ago
For one thing, it's the ultimate form of copy protection.
- planteen 10y ago
  But most cartridges used the same design. So if you had one SuperFX cartridge, you could put it in your copiers cartridge slot and then play all the others.
  - b409ba0801cd21 10y ago
    That was true of the DSP-1, but not true of the SuperFX or SA1. The DSP-1 was a preprogrammed microcontroller that preformed certain calculations that would have been inefficient to preform on the SNES CPU. The inputs were written to a memory mapped location, and the outputs read back. An interposed copier could simply redirect these reads and writes. The SuperFX and SA1 used the cartridge's ROM and RAM for program and data, and therefore these enhancement chips are placed between the SNES bus and the cartridge memory. The cartridge memory is unavailable to the SNES bus while the enhancement chip is executing, as in the SuperFX, or the the enhancement chip enters wait states while the CPU is accessing the cartridge memory, as in the SA1.
    - planteen 10y ago
      Ah gotcha. My memory is getting hazy. I had a floppy disk copier many years ago and remember using Mario Kart to play other games. I thought it was SuperFX but I was wrong.

pcwalton 10y ago

> And by "enhancement" I mean the SuperFX chip basically ran the game and the SNES just provided power and A/V out. Sorta—there was no direct video out from the cartridge on the SNES (though oddly enough, there were audio out pins), so the Super FX chip had to actually generate sprites on the fly for the PPU to composite together. This resulted in unfortunate color limitations. You can see in the debug info for Star Fox 2 that the dynamically allocated sprite count was something that they had to constantly keep track of: https://r.mprd.se/fup/up/35454-Star_Fox_2_(Japan)_(Proto)_(Alt_1)_[En_by_Aeon_Genesis_v1.0]_(Debug_Version)-1460132615.png https://r.mprd.se/fup/up/35454-Star_Fox_2_(Japan)_(Proto)_(A...