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Does $4200 have to only be written to once?
http://forums.nesdev.com/viewtopic.php?f=12&t=16470
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Author:  psycopathicteen [ Sat Sep 09, 2017 2:18 pm ]
Post subject:  Does $4200 have to only be written to once?

I know $4210 has to be read once per frame to stop NMI, but does that reset $4200?

Author:  Pokun [ Tue Sep 12, 2017 3:36 am ]
Post subject:  Re: Does $4200 have to only be written to once?

I don't think so from reading Nintendo's dev docs. Reading $4210 acknowledges NMI and resets the NMI Flag (bit 7 of $4210), but NMIs are only enabled/disabled using bit 7 of $4200.

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