Mapper: Difference between revisions

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A '''mapper''' is a piece of hardware soldered to a cartridge's printed circuit board that performs address decoding, [[Wikipedia:bank switching|bank switching]], and possibly interrupt generation for timing.
A '''mapper''' is a piece of hardware soldered to a cartridge's printed circuit board that performs address decoding, [[Wikipedia:bank switching|bank switching]]. A mapper may also generate interrupts for timing; some Famicom games' mappers even have extra audio channels.


NES cartridges can include extra hardware which allows the use of large program and graphics ROMs and extra features. This extra hardware is usually referred to as a "mapper", as it is used primarily to map the relatively small CPU and PPU address spaces to a portion of the larger address space of the ROM(s) on the cartridge.
NES cartridges can include extra hardware which allows the use of large program and graphics ROMs and extra features. This extra hardware is usually referred to as a "mapper", as it is used primarily to map the relatively small CPU and PPU address spaces to a portion of the larger address space of the ROM(s) on the cartridge.
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The emulation community generally refers to mappers by a numbering scheme that originated with the [[iNES]] emulator (e.g. "mapper 002").
The emulation community generally refers to mappers by a numbering scheme that originated with the [[iNES]] emulator (e.g. "mapper 002").


=== Programmer's reference ===
== See also ==
* Nintendo: [[MMC1|MMC1]], [[MMC2|MMC2]], [[MMC3|MMC3]], [[MMC4|MMC4]], [[MMC5|MMC5]]/[[MMC5_audio|audio]], [[MMC6|MMC6]]
* Nintendo: [[MMC1]], [[MMC2]], [[MMC3]], [[MMC4]], [[MMC5]] with [[MMC5_audio|audio]], [[MMC6]]
* Konami: [[VRC1|VRC1]], [[VRC2|VRC2]], [[VRC3|VRC3]], [[VRC4|VRC4]], [[VRC6|VRC6]]/[[VRC6_audio|audio]], [[VRC7|VRC7]]/[[VRC7_audio|audio]], [[VRC_irq|VRC irqs]]
* Konami: [[VRC1]], [[VRC2]], [[VRC3]], [[VRC4]], [[VRC6]] with [[VRC6_audio|audio]], [[VRC7]] with [[VRC7_audio|audio]], [[VRC irq]]s
* Others: [[Color Dreams]], [[NINA-101]], [[NINA-003-006|NINA-003/006]], [[SUBOR|SUBOR]]
* Others: [[Color Dreams]], [[NINA-101]], [[NINA-003-006|NINA-003/006]], [[SUBOR]]
*[[:Category:Discrete logic mappers|List of discrete logic mappers]]
*[[:Category:Discrete logic mappers|List of discrete logic mappers]]
*[[:Category:INES Mappers|List of iNES mapper numbers]]
*[[:Category:INES Mappers|List of iNES mapper numbers]]
== See also ==
* [[Hardware pinout]], including mapper pinouts
* [[Hardware pinout]], including mapper pinouts


== External links ==
== External links ==
* For a more exhaustive resource of mappers, Disch compiled a very detailed list of mappers all in one, covering more than 50 [[http://www.romhacking.net/docs/362/ mappers]].
* [http://www.romhacking.net/docs/362/ Disch's detailed list of over 50 mappers] at romhacking.net


[[Category:Mappers|*]]
[[Category:Mappers|*]]

Revision as of 17:09, 28 November 2009

A mapper is a piece of hardware soldered to a cartridge's printed circuit board that performs address decoding, bank switching. A mapper may also generate interrupts for timing; some Famicom games' mappers even have extra audio channels.

NES cartridges can include extra hardware which allows the use of large program and graphics ROMs and extra features. This extra hardware is usually referred to as a "mapper", as it is used primarily to map the relatively small CPU and PPU address spaces to a portion of the larger address space of the ROM(s) on the cartridge.

Mappers vary in how they translate addresses. The various CPU memory mapping schemes expand the maximum program size above the standard 32 KiB to larger powers of 2, while PPU memory mapping schemes can add new graphic features.

Most mappers fall into one of two categories: discrete logic, and ASIC based. Some discrete logic mappers are susceptible to bus conflicts. Nintendo uses the term Memory Management Controller (or MMC for short) for its ASIC mappers ("Why Game Paks Never Forget" article in Nintendo Power).

Discrete logic mappers are often referred to by the name of a board that they are commonly used in (e.g. "UNROM"). ASIC mappers are named after the ASIC (e.g. "MMC1" or "FME-7"). The emulation community generally refers to mappers by a numbering scheme that originated with the iNES emulator (e.g. "mapper 002").

See also

External links