Editing MOS Technology 6502 (section)

{{Short description|8-bit microprocessor from 1975}}

{{Infobox CPU
|name         = MOS Technology 6502
|image        = MOS 6502AD 4585 top.jpg
|caption      = 6502 processor in a [[Dual in-line package|DIP-40]] plastic package. The four-digit [[date code]] indicates it was made in the 45th week (November 4–10) of 1985.
|produced-start={{Start date and age|1975}}
|produced-end = 
|slowest      = 1 |slow-unit=MHz
|fastest      = 3 |fast-unit=MHz
|manuf1=[[MOS Technology]], [[Rockwell International|Rockwell]], [[Synertek]]
|arch         = MOS 6502
|transistors  = 3,510,<ref>{{cite web |title=The MOS 6502 and the Best Layout Guy in the World |publisher=swtch.com |date=2011-01-03 |access-date=2014-08-09 |url=http://research.swtch.com/6502 |archive-date=2014-09-08 |archive-url=https://web.archive.org/web/20140908121520/http://research.swtch.com/6502 |url-status=live}}</ref> 3,218<ref>{{cite web |title=MOnSter6502 A complete, working discrete transistors (i.e. not integrated all on a single chip) replica of the classic MOS 6502 microprocessor |publisher=monster6502.com |date=2017 |access-date=2017-05-01 |url=http://monster6502.com/ |archive-date=2017-05-12 |archive-url=https://web.archive.org/web/20170512051122/http://monster6502.com/ |url-status=live }}</ref>
|numinstructions = 56 (55 originally)
|data-width   = [[8-bit computing|8 bits]]
|address-width=[[16-bit computing|16 bits]]
|pack1=40-pin [[Dual in-line package|DIP]]
|predecessor  = {{Plainlist|
*[[Motorola 6800]]
*MOS 6501}}
|successor    = {{Plainlist|
*[[MOS Technology 6510|MOS 6510]]
*[[WDC 65C02]]
*[[WDC 65C816]]}}
}}

The '''MOS Technology 6502''' (typically pronounced "sixty-five-oh-two" or "six-five-oh-two")<ref name="Mensch interview">{{cite interview |url=https://exhibits.stanford.edu/silicongenesis/catalog/kb642ng6104 |title=Interview with William Mensch |date=October 9, 1995 |medium=Web video |publisher=[[Silicon Genesis Project]], Stanford University Libraries |location=Atherton, California |subject=William Mensch |interviewer=Rob Walker |access-date=December 22, 2023 |archive-date=March 4, 2016 |archive-url=https://web.archive.org/web/20160304091031/http://silicongenesis.stanford.edu/transcripts/mensch.htm |url-status=live }} William Mensch and the moderator both pronounce the 6502 microprocessor as ''"sixty-five-oh-two"''.</ref> is an [[8-bit computing|8-bit]] [[microprocessor]] that was designed by a small team led by [[Chuck Peddle]] for [[MOS Technology]]. The design team had formerly worked at [[Motorola]] on the [[Motorola 6800]] project; the 6502 is essentially a simplified, less expensive and faster version of that design.

When it was introduced in 1975, the 6502 was the least expensive microprocessor on the market by a considerable margin. It initially sold for less than one-sixth the cost of competing designs from larger companies, such as the 6800 or [[Intel 8080]]. Its introduction caused rapid decreases in pricing across the entire processor market. Along with the [[Zilog Z80]], it sparked a series of projects that resulted in the [[home computer]] [[microcomputer revolution|revolution]] of the early 1980s.

[[Home video game console]]s and home computers of the 1970s through the early 1990s, such as the [[Atari 2600]], [[Atari 8-bit computers]], [[Apple II]], [[Nintendo Entertainment System]], [[Commodore 64]], [[Atari Lynx]], [[BBC Micro]] and others, use the 6502 or variations of the basic design. Soon after the 6502's introduction, MOS Technology was purchased outright by [[Commodore International]], who continued to sell the microprocessor and licenses to other manufacturers. In the early days of the 6502, it was [[second source|second-sourced]] by [[Rockwell International|Rockwell]] and [[Synertek]], and later licensed to other companies.

In 1981, the [[Western Design Center]] started development of a [[CMOS]] version, the [[WDC 65C02|65C02]]. This continues to be widely used in [[embedded system]]s, with estimated production volumes in the hundreds of millions.<ref>{{Cite web|url=http://www.westerndesigncenter.com/wdc/|title=Western Design Center (WDC) Home of 65xx Microprocessor Technology|website=www.westerndesigncenter.com|access-date=2019-04-08|archive-date=2019-04-08|archive-url=https://web.archive.org/web/20190408025716/http://www.westerndesigncenter.com/wdc/|url-status=live}}</ref>