Well, I'm making slow but steady progress on the mainboard. I cleaned up the SNES core schematic, which was a disgusting EAGLE mess before because I didn't know what I was doing.
The Super Everdrive schematic is done, and the routing is in progress.
What I'm dreading is the cartridge slot connections. Both the Everdrive and cart slot ZIF connect to the SNES core through level shifter-buffers (so that both can be enabled/disabled at will). That means three different cartridge buses (SNES, slot, Everdrive) need to merge below the 1-Chip in a sane way. Gonna be rough, but I'll figure it out. I'm doing via-in-pad for everything to buy myself as much space as possible.
The build will use iPhone 15 Pro Max loudspeakers. Smartphone speakers have compact enclosures designed by the world's top audio engineers, and little styrofoam balls to make the chamber acoustically larger than its physical volume would suggest. TL;DR they sound very bassy and rich for their size! Have a listen!
With super crisp video that looks like an emulator, and super crisp audio using the
Scampi architecture, this portable will be the ultimate way to play SNES on the go!!!
For those concerned about the inclusion of a Super Everdrive instead of an SD2SNES, I get it. I did want to have an SD2SNES initially, but the fact is that the SD2SNES circuitry is outrageously large and complex, while only enabling ~12 additional
(good) games to be played:
- Megaman X2 and X3
- Super Mario RPG
- Super Mario Kart
- Pilotwings
- Super Mario World 2
- Star Ocean
- Ballz 3D
- Star Fox
- Kirby Super Star
- Kirby's Dream Land 3
- Doom
And here's the difference in implementation size / complexity between ED (top) and SD2SNES. Note that this is with BGA replacements for the SD2SNES, but not for the Everdrive. The Everdrive could be even smaller with BGA flash.
The SD2SNES also has to be programmed at startup, which is a kinda arduous process involving flashing the PIC, swapping the SD card multiple times, and power cycling it. Super Everdrives, on the other hand, are literally
$17 on AliExpress, and the chips can be transplanted with no fuss.
So, in the interest of picking my battles, I will "settle" for 98% library playability via Everdrive, and play expansion chip games via real carts or an SD2SNES in the cart slot. Maybe this compromise will help me actually finish the project
