Author Topic: Sup 400-in-1 handheld dump  (Read 4700 times)

The_YongGrand

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Sup 400-in-1 handheld dump
« on: November 17, 2020, 10:44:31 AM »
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.
« Last Edit: January 31, 2023, 09:50:57 AM by The_YongGrand »

NewRisingSun

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Re: Sup 400-in-1 handheld dump
« Reply #1 on: November 17, 2020, 06:31:09 PM »
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.
« Last Edit: November 17, 2020, 06:35:44 PM by NewRisingSun »

The_YongGrand

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Re: Sup 400-in-1 handheld dump
« Reply #2 on: November 18, 2020, 05:36:39 AM »
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.