Sup 400-in-1 ROM dump analysis (VT-XX system?) - TFT initialization routines

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The_YongGrand
Posts: 29
Joined: Tue Mar 19, 2013 9:30 am

Sup 400-in-1 ROM dump analysis (VT-XX system?) - TFT initialization routines

Post by The_YongGrand »

Hi there,

I got a couple of the Sup 400-in-1 Handheld console which is popular in SE Asia: Image

... and I had took out the little ROM board for dumping. Earlier on, the ROM dump was incomplete due to connecting the wrong address lines, and recently I got another schematic from somewhere and tried it - the dump actually worked in EmuVT:
1NSMVRX.png
However, I am very curious on how the firmware actually initialize its TFT. The startup code from the beginning was showing writes to 0x4107 and 0x4108 which possibly refers to the OneBus mechanism.
400in1_init.PNG
400in1_init.PNG (4.92 KiB) Viewed 2715 times
I checked these VT-03, VT-16, VT-18 for the TFT and LCD registers and the code after the address 0x7ff01 doesn't seem to write to any of these registers that are mentioned in the datasheet. Maybe the initialization routines are stored inside another ROM inside the NOAC. But from the Youtube videos, when uploading custom ROM inside the handheld, the screen got disabled (and the TV out is active), so I suspect there could be init routines beforehand:

https://www.youtube.com/watch?v=xjbU4m2szbE

https://www.youtube.com/watch?v=XzvhbVjI8a0

I'm not sure if it's legal to put a link of the ROM dump - let me know if its okay or not. I'm not familiar with the VT-XX architecture and only getting these info from various forums. :D
The_YongGrand
Posts: 29
Joined: Tue Mar 19, 2013 9:30 am

Re: Sup 400-in-1 ROM dump analysis (VT-XX system?) - TFT initialization routines

Post by The_YongGrand »

Here's the ROM dump from the forum http://bootleg.games/BGC_Forum/index.php?topic=3138.0. Thanks to NewRisingSun for the help in making it work on the NintendulatorNRS. :D
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