Ricoh 2A03: Difference between revisions

| produced-start = 1983{{Start (40date Years)and age|1983}}

The Ricoh 2A03<ref name="visual6502">{{cite web|url=http://visual6502.org/images/pages/Nintendo_RP2A_die_shots.html|title=Nintendo RP2A03 and RP2A07|last=Sattler|first=Christian|website=visual6502.org|access-date=2020-08-12}}.</ref> contains aan [[secondunlicensed source|second-source]]dderivative of the [[MOS Technology 6502]] core, modified to disable the 6502's [[binary-coded decimal]] mode (possibly to avoid a MOS Technology patent<ref>[https://patents.google.com/patent/US3991307 Patent US3991307]</ref>). It also integrates a [[programmable sound generator]] (also known as APU, featuring twenty two [[memory-mapped I/O]] registers),<ref>{{Cite web|url=http://www.atkinsoft.com/soundgenerators.html|title=Sound generators of the 1980s home computers|website=www.atkinsoft.com|access-date=2019-12-02}}</ref> rudimentary [[Direct memory access|DMA]], and game controller polling.<ref name="2A03techref">{{cite web|url=https://www.nesdev.com/2A03%20technical%20reference.txt|title=2A03 technical reference|last=Taylor|first=Brad|date=April 23, 2004|website=NesDev.com|archive-url=https://web.archive.org/web/20181017163239/https://www.nesdev.com/2A03%20technical%20reference.txt|archive-date=October 17, 2018|url-status=live|access-date=June 6, 2008}}</ref>

PAL versions of the NES (sold in Europe, Asia, and [[Video gaming in Australia|Australia]]) use the '''Ricoh 2A07''' or '''RP2A07''' processor, which is a 2A03 with modifications to better suit the 50&nbsp;[[Hertz|Hz]] [[Refresh rate|vertical refresh rate]] used in the PAL television standard. However, most developers lacked the resources to properly adjust their games' music from NTSC to PAL, leading to many PAL games sounding slower, slightly lower-pitched, and in some cases, out-of-tune compared to their original NTSC releases.<!--{{citation missingneeded|date=April source; this was common2024|reason=Common on computers, but on consoles? -->}}