Editing Memory management controller (Nintendo) (section)

==Third-party chips==
Nintendo maintained tight control over internationally-released cartridge hardware and did not allow third parties to use their own PCBs and mappers. This remained the case until late in the NES's commercial lifespan when Nintendo eased up the restrictions. As a result, most third party mappers will only be found in Famicom or unlicensed cartridges.

===VRC1===
* Manufacturer: Konami, Jaleco (SS8805)
* Games: ''Exciting Boxing'', ''Ganbare Goemon! Karakuri Douchuu'', ''Jajamaru Ninpouchou'', ''King Kong 2: Ikari no Megaton Punch, Moero!!'', ''Junior Basket: Two on Two'', ''Tetsuwan Atom''<ref>{{Cite web|url=https://wiki.nesdev.com/w/index.php/VRC1|title=VRC1 - Nesdev wiki|website=wiki.nesdev.com|language=en|access-date=January 18, 2017}}</ref>

===VRC2===
* Manufacturer: Konami
* Games: ''[[Contra (video game)|Contra]]''<sup>JP</sup>, ''[[Tiny Toon Adventures (video game)|Tiny Toon Adventures]]''<sup>JP</sup>, ''[[Kid Dracula (1990 video game)|Akumajō Special: Boku Dracula-kun]]''
The VRC2 is a chip from Konami that allows program ROM to be switched in 8KB banks, and character ROM to be switched in 1KB banks. This MMC has two known revisions: VRC2a and VRC2b.<ref>{{Cite web|url=http://wiki.nesdev.com/w/index.php/VRC2|title=VRC2 and VRC4 - Nesdev wiki|website=wiki.nesdev.com}}</ref>

===VRC3===
* Manufacturer: [[Konami]]
* Games: ''[[Salamander (video game)|Salamander]]''<sup>JP</sup>
Exclusively used in the Japanese version of ''Salamander''.

===VRC4===
[[File:VRCIV 2-TYPE 01.jpg|thumb|right|The VRC4]]
* Manufacturer: [[Konami]]
* Games: ''[[Gradius II]]''<sup>JP</sup>, ''[[Crisis Force]]'', ''Bio Miracle:Boku tte Upa'', ''Ganbare Goemon Gaiden 2'', ''WaiWai World'', ''WaiWai World 2'', ''Twinbee 3''<ref>{{Cite web|url=https://mednafen.github.io/documentation/nes.html|title=Mednafen Nintendo Entertainment System/Famicom Documentation|website=mednafen.github.io|access-date=January 18, 2017}}</ref>
The VRC4 Chip is similar to the VRC2 chip, other than the VRC4 allowing for 512KB CHR capacity, 2 8KB PRG ROM banking modes and 1 screen mirroring.

===VRC5===
* Manufacturer: [[Konami]]
* Games: ''Space School''<sup>JP</sup>
Exclusively used in the QTa adapter in Konami's ''Space School'' series of educational games.<ref>{{Cite web|url=https://arstechnica.com/gaming/2019/08/collector-unearths-long-lost-8-bit-konami-games-dumps-them-for-emulation|title=Collector unearths long-lost 8-bit Konami games, dumps them for emulation|website=Arstechnica|date=August 29, 2019 |access-date=August 29, 2019}}</ref>

===VRC6===
[[File:vrc6.jpg|thumb|right|The VRC6]]
* Manufacturer: [[Konami]]
* Games: ''[[Castlevania III: Dracula's Curse|Akumajō Densetsu]]'', ''Mōryō Senki MADARA'', ''[[Esper Dream|Esper Dream II]]''
The VRC6 (Virtual Rom Controller) is an advanced MMC chip from Konami, supporting bank switching for both program code and graphics as well as a CPU cycle–based [[Interrupt request|IRQ]] counter, which can also act as a scanline counter. The chip also contains support for three extra sound channels (two [[Square wave (waveform)|square wave]]s of eight [[duty cycle]]s each, which can be configured to play PCM samples using 100% duty cycle, and one [[sawtooth wave]]). It is used in ''Akumajō Densetsu'', the Japanese version of ''[[Castlevania III: Dracula's Curse]]'', while the Western version uses the MMC5 from Nintendo. Since the [[Nintendo Entertainment System]] by design does not allow cartridges to add additional sound channels, the Famicom version's soundtrack was reworked to follow those specifications; the soundtrack for the Western version utilizes the five stock sound channels built into the NES.<ref name="Gamasutra">{{cite web|title=Breaking the NES for Shovel Knight|url=https://www.gamedeveloper.com/design/breaking-the-nes-for-shovel-knight|website=[[Gamasutra]]|last=D'Angelo|first=David|date=June 25, 2014}}</ref>

===VRC7===
[[File:KVRC7.JPG|thumb|The VRC7 with a post-processor for FM synthesis]]
* Manufacturer: [[Konami]], [[Yamaha Corporation|Yamaha]]
* Games: ''[[Lagrange Point (video game)|Lagrange Point]]'', ''[[Tiny Toon Adventures 2: Trouble in Wackyland]]''<sup>JP</sup>
The VRC7 is an advanced MMC chip from Konami, supporting bank switching and IRQ counting equivalent to the VRC6, as well as containing a [[YM2413]] derivative providing 6 channels of 2-op [[Frequency modulation synthesis|FM synthesis]]. The advanced audio hardware is used only in the Famicom game ''Lagrange Point''. The Japanese version of ''Tiny Toon Adventures 2'' also uses the VRC7 but does not take advantage of the extended audio.<ref>{{Cite web |title=VRC7 - Nesdev wiki |url=https://www.nesdev.org/wiki/VRC7 |website=www.nesdev.org}}</ref><ref>{{Cite web|url=https://www.nesdev.org/wiki/VRC7_audio|title=VRC7 audio|website=NESdev Wiki}}</ref> A disadvantage of the extended audio portion is that it produces some quantization noise, noticeable at lower notes. This was a carryover from the YM2413, which the VRC7's FM chip is based on.

===Namco 163===
* Manufacturer: [[Namco]]
* Games: ''[[Erika to Satoru no Yume Bōken]]'', ''[[Final Lap]]'', ''[[King of Kings (1988 video game)|King of Kings]]'', ''[[Mappy Kids]]'', ''[[Digital Devil Story: Megami Tensei II]]'', ''Namco Classic II'', ''[[Romance of the Three Kingdoms (video game series)|Romance of the Three Kingdoms]]'', ''[[Romance of the Three Kingdoms II]]'', ''[[Yokai Dochuki]]'', ''[[Rolling Thunder (video game)|Rolling Thunder]]''<sup>JP</sup>, ''Top Striker''
The 163 has been only used in games exclusive to Japan. Its capabilities were a little better than Nintendo's MMC3. A variant contained extra sound hardware that plays 4-bit wave samples. It supports 1 to 8 extra sound channels, but audible [[aliasing]] appears when a sufficiently large number of channels are enabled due to the increasingly audible [[time-division multiplexing]].{{citation needed|date=September 2023}}

===FME-7===
* Manufacturer: [[Sunsoft]]
* Games: ''[[Batman: Return of the Joker]]'', ''[[Hebereke]]'', and more.
The FME-7 is a memory mapping circuit developed by Sunsoft for use in NES and Famicom cartridges. It switches program ROM in 8KB banks and switches the character ROM 1KB banks. It also contains hardware to generate [[Interrupt request|IRQ]] signals after a specified number of CPU [[clock cycle]]s, thus achieving split-screen effects with minimal use of processing power.{{Citation needed|date=September 2023}}

===SUNSOFT-4===
[[File:SUNSOFT-4 01.jpg|thumb|right|SUNSOFT-4]]
* Manufacturer: [[Sunsoft]]

===SUNSOFT 5B===
* Manufacturer: [[Sunsoft]]
* Games: ''[[Gimmick!]]''
This version of the FME-7 contains a variant of the widely used [[Yamaha YM2149]] (SSG), a derivative of the popular [[AY-3-8910]] chip.{{citation needed|date=September 2023}}