Hi! Finally I got to revisit it again after checking the disassembly of the software in this github.

The problem with it is, right now it is very difficult to compile and load the games because:

• manually place the game graphics and code
• set the OneBus registers
• and recompile.

No, the Nesmaker from NesDev doesn't work - the init code does not match whatever hardware that is on the handhelds. I have read this over and over again to be sure, and I'm open to new feedback for this one! :D

I have written this builder to facilitate the task of loading Mapper 0 and 4 games and then compile it with the initialization ROM (again, you need to get the ROM dump from the handheld, and the build folder from the custom menu template!):

This compiles the whole thing into the BIN file for the emulator, and also a separate BIN file for the handheld. There are variations on these handheld such as bit swaps so after all the compilation it reverses whatever it is to be workable for the unit.

However, the recent one I'm testing are the TSOP-56 variant - the ones with the S29GL flash. It looks... easy right, since I can undo it through the hot air...?

Not really! Yes, with enough experience, I could do it a few times, but repeated cycles of unsoldering, reflashing and soldering could make these flimsy traces snap very easily! I have messed up one board because of this!

Worse of all, do not use a vice to hold the PCB of that unit too tightly! Flexing the board would means it breaks immediately!

Imitating previous work of mine, I might be doing a TSOP-56 version for this one so the board doesn't have to tolerate too many of the repeated cycles of de/soldering. :D