Bootleg Games Central Forum
Pirate Discussion => Famicom/NES => Famicom/NES dumps => Topic started by: The_YongGrand on November 17, 2020, 10:44:31 AM
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Hello there,
I just happened to extract the COB ROM and tried to dump the contents using the Raspberry Pi and a couple of MCP23017s. [Story here: https://hackaday.io/project/175322-dissecting-a-hand-held-noac-console]
I tried running this on the Nintendulator which is modified for VT-series NOAC but couldn't run. I'm suspecting this one is a possible variant of the VT series where the reset vector is entirely different.
Inside the dump I could see sprite sheets as usual with some data in between, but I couldn't find a lot of references on the 400-in-1 menu text. It could be possibly encrypted or the dump is incomplete.
The dump is attached here for the reference.
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The dump does seem awfully small for the given number of games, even when accounting for repeated titles. I could not find any writes anywhere in the entire ROM image to important VTxx registers $4100 or $410B, so my assessment is that the menu is just missing. I also could not find the CHR data of some of the games depicted in the various YouTube video describing this handheld.
I find the "variant of the VT series where the reset vector is entirely different" explanation extremely unlikely. The only VT series chip that allows such a thing and that is still NES-compatible is the VT369, which allows the reset vector to be stored inside a 4 KiB ROM that is embedded in the NOAC chip itself. In every known instance, that 4 KiB ROM only contained code to download and execute LCD initialization code from an external serial EPROM, and the other 2 KiB half containing code for the sound CPU. Even if one allowed for a super-special embedded ROM variant, it would not fit an entire menu.
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Hello @NewRisingSun,
Thanks for the feedback - I found out in my Python script that I dumped only the first half.
I'm in the process of dumping the other half and then proceed to "glue" onto that one after it's all done.