Talk:Errata

Some things to add by people who know what these refer to:

PPU: must wait a couple of vblanks before chip is fully active

PPU: can't reliably write to ports more often than several CPU cycles apart

Page-crossing pointer quirks:

JMP ($nnnn)

($nn),Y

($nn,X)

I don't understand this ceaveat

 In horizontal or 4-screen mirroring, writing $2000 at the exact start of horizontal blanking may cause the PPU to start reading from the first pattern table instead of the second.
 (Workaround: Don't disable NMI during active picture. Instead, use a variable to lock out reentrant NMI.)

Can someone rewrite it with a better wording so that non-native english speakers understand it ? Bregalad (talk) 05:12, 4 November 2013 (MST)

Errata in the errata? Chalk it up to Muphry's law. --Tepples (talk) 15:54, 4 November 2013 (MST)

This was the SMB bug where on 1/3 power-ons, the PPU alignment allows the mid-screen write to $2000 to interfere with the nametable selection on the next line if perfectly (unfortunately) timed. It results in one line of the screen being rendered with the wrong nametable. What do you think would help the wording, Bregalad? Rainwarrior (talk) 09:52, 5 November 2013 (MST)