Evercade

So, how to add new games to an Evercade cartridge ?
It's certainly possible but kind of defeats the purpose of this console, there are other handhelds on the market more suitable to loading with zillions of roms.

Anyhow..

Each cartridge contains a single flash memory, this device MKDV 1GCL-NE is a 1Gb SD flash chip. So its basically a 128MB SD Card but soldered to the cartridge.





So, if its a SD card we should be able to mount it and see whats on it, assuming its got a standard filesystem and not encrypted.

The pinout of the cartridge works out to be:

Pin 1 - DAT2
Pin 2 - DAT3
Pin 3 - CMD
Pin 4 - VDD
Pin 5 - CLK
Pin 6 - GND
Pin 7 - DAT0
Pin 8 - DAT1

Initially I soldered this directly to a cheapo USB card reader and was able to read and write to the card successfully - its using the FAT16 filesystem.

Obviously with the cartridge soldered to the card reader its difficult to stick it back in the console, so needed a better solution. Well, turns out the card edge on the cartridge is the same as a Gameboy cart so a connectors was taken from a dead Gameboy - the edges to the connector need to be filed out a bit before the Evercade cartridge would fit correctly.



So, whats on the cartridge then ?



Emulators: we've got blastem Megadrive emulator and a couple of Retroarch core libraries for the NES & SNES emulation.

launch.sh - this is called by the the console to startup whatever game you've selected.

/usr/bin/retroarch -y "12"\
-c "$2"\
-L /sdcard/$GAME_LIB "$3"\

Games:


Here each game installed has 7 files associated with it.

The game Burnin Force has the following files:

NM2BF.md - Game ROM
NM2BF0.png - Cover art (112 x 157 pixels)
NM2BF0_hd.png - Cover art (210 x 295 pixels)
NM2BF1.png - Screenshot (193 x 146 pixels)
NM2BF1_hd.png - Screenshot (418 x 295 pixels)
NM2BF2.png - Banner (340 x 50 pixels)
NM2BF2_hd.png - Banner (920 x 128 pixels)

The naming convention is the same on all the carts I looked at.

<Cartidge Name><Game identifier><Image>
AT1 - Atari Collection 1
IP1- Interplay 1
PI1 - Piko Interactive 1
NM1 - Namco Collection 1
NM2 - Namco Collection 2

Adding another game to the cartridge is just a matter of replicating these files for each game you add. The console scan the cartridge on boot and builds the list based on what it finds.
I'm not sure all the files are actually necessary but I added them anyway and resized the images to the correct dimensions.

For Zero Wing I added files:

NM2ZW.md, NM2ZW0.png, NM2ZW0_hd.png, NM2ZW1.png, NM2ZW1_hd.png, NM2ZW2.png, NM2ZW2_hd.png