Category:Mappers with battery-backed CHR-RAM: Difference between revisions
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[[Category:Mappers with CHR RAM]] | |||
Very few boards use a battery to retain the content of CHR-RAM. The purpose of doing so is presumably that if a game already uses CHR-RAM [[CHR ROM vs. CHR RAM|for other reasons]] and only has a few bytes of save data to retain, storing these bytes in the same CHR-RAM chip (and sacrificing available tile numbers in the process) and connecting a battery to it is more economical than adding a separate WRAM chip. | Very few boards use a battery to retain the content of CHR-RAM. The purpose of doing so is presumably that if a game already uses CHR-RAM [[CHR ROM vs. CHR RAM|for other reasons]] and only has a few bytes of save data to retain, storing these bytes in the same CHR-RAM chip (and sacrificing available tile numbers in the process) and connecting a battery to it is more economical than adding a separate WRAM chip. | ||
[http://forums.nesdev.org/viewtopic.php?f=2&t=16925 Nintendo's early MMC1 data sheet] mentions an "SLROM" board with 8 KiB of battery-backed CHR-RAM. The actual [[SLROM]] board that went into production uses CHR-ROM and no PRG-RAM or CHR-RAM at all. | [http://forums.nesdev.org/viewtopic.php?f=2&t=16925 Nintendo's early MMC1 data sheet] mentions an "SLROM" board with 8 KiB of battery-backed CHR-RAM. The actual [[SLROM]] board that went into production uses CHR-ROM and no PRG-RAM or CHR-RAM at all. | ||
Latest revision as of 20:39, 31 May 2018
Very few boards use a battery to retain the content of CHR-RAM. The purpose of doing so is presumably that if a game already uses CHR-RAM for other reasons and only has a few bytes of save data to retain, storing these bytes in the same CHR-RAM chip (and sacrificing available tile numbers in the process) and connecting a battery to it is more economical than adding a separate WRAM chip.
Nintendo's early MMC1 data sheet mentions an "SLROM" board with 8 KiB of battery-backed CHR-RAM. The actual SLROM board that went into production uses CHR-ROM and no PRG-RAM or CHR-RAM at all.
Pages in category "Mappers with battery-backed CHR-RAM"
The following 2 pages are in this category, out of 2 total.
