Not entirely sure if you're still looking for info on this, but generally the ICs are made by one or two companies and are then bought and shoved into various toys. There's more info spread out across https://chinafake.wiki.

Quote from: GroupNebula563 on May 10, 2024, 03:25:35 AM

Quote from: lancuster on February 10, 2024, 02:44:57 PM

I could have converted the title screen and the missing graphics from the original if the game had been converted to the standard NES format.

What do you mean by "standard nes format"? You can't just convert a game from VT03 to NES.

This is possible if you rewrite the registers to fit the standard NES mapper, and redo the graphics to the standard 2bpp format.
The program code, sound engine, and so on in the game are still sharpened for NES hardware.

Yeah, but at that point why bother porting the game to change one small title screen issue to then have to port it back…

Quote from: Y2K05 on April 30, 2024, 08:28:53 PM

Yeah, but I mean if UM5678 cannot be converted, no way that it can be done for VT03 without reprogramming it excessively.

Nevertheless, we managed to port "Commando" and "Curly Monkey" from VT03 to the standard MMC3 format, without resorting to serious reprogramming.

MMC3 is a mapper, the game still needs to run on VT03 hardware (if I’m not mistaken)

Don’t know what happened, but Cheer-Tech's main page got replaced with some scam site. Thankfully, the rest of the website seems to still function fine, and after a bit of messing around I found the old index page at http://www.cheertech.com.hk/index1.html! There’s also still a default index page at http://www.cheertech.com.hk/index.htm.

Because one doesn't exist already.