As the title describes, id like to know exactly how and what's needed to mod the nes, to deliver the mmc5s pulse channels? And does this work foe the mmc5s pcm as well? Thank you.
On the NES-ExROM board, you'll find a bunch of places for R1, R2, R4, R9, C2, and C3. They also have sizes specified.
Ste p one: Stuff all six of those components with the marked sizes.
Step two: Add a ~100kiloohm potentiometer between NES expansion port pins 9 (EXP6) and 3 (audio in). Adjust value to make the volume nice.
Cheapo alternative: Instead just add a ≥100nF capacitor in lieu of R1, and connect an RCA jack in lieu of C2. (Dangle the RCA jack out the top front of the cartridge). This will omit the DAC, but seriously, no-one cares about the DAC except your hack.
Oh is the mod for an mmc5 cartridge? I though I read online years ago, that the Nintendo console needed to he modified, to output the extra sound the mmc5 itself produces?
Both parts need to be modified. (Hence step one (MMC5) and step two (NES))
Oh I apologize. Thank you. I find it odd an actual mmc5 cartridge needs to be modified, for a function the mapped claims to produce . Is this solely because of the nes's design lacking proper output?
Nah. I'm not really clear why the NES MMC5 cartridges left the solder pads for the expansion audio on the PCB—I honestly would have expected them to leave all four pins on the IC itself just bare, not connected to anything.
In any case, because including those 6 parts wouldn't have produced sound on any NESes, they saved the 20-ish cents per cartridge for the parts by not stuffing them.