Talk:MMC1: Difference between revisions

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m (→‎SOROM, SUROM, and SXROM: clarify that I mean they look like the same submapper, i.e. 1 submapper instead of 3?)
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  0:C - 4k CHR banking control
  0:C - 4k CHR banking control


What am I missing? I can't spot the incompatibility that necessitated the submappers? - [[User:Rainwarrior|Rainwarrior]] ([[User talk:Rainwarrior|talk]]) 00:58, 8 August 2015 (MDT)
What am I missing? I can't spot the incompatibility that necessitated three submappers. Isn't this just one mapper together? - [[User:Rainwarrior|Rainwarrior]] ([[User talk:Rainwarrior|talk]]) 00:58, 8 August 2015 (MDT)

Revision as of 07:11, 8 August 2015

SOROM, SUROM, and SXROM

I'm a little fuzzy about why these are considered different NES 2.0 submappers. The functionality of all three of these looks the same to me if the extra banking bits become useless/mirror when the ROM/RAM addressed is a smaller size (just like in any other mapper supporting various sizes).

43210
+---+
PSSxC
4:P - A18 of 512k PRG ROM, disconnected if smaller
3:S - A13 of 16k PRG RAM, disconnected if smaller
2:S - A14 of 32k PRG RAM, disconnected if smaller
1:x - unused
0:C - 4k CHR banking control

What am I missing? I can't spot the incompatibility that necessitated three submappers. Isn't this just one mapper together? - Rainwarrior (talk) 00:58, 8 August 2015 (MDT)