Editing Von Neumann architecture (section)

==Evolution==
[[File:Computer system bus.svg|thumb|Single [[system bus]] evolution of the architecture]]

Through the decades of the 1960s and 1970s computers generally became both smaller and faster, which led to evolutions in their architecture. For example, [[memory-mapped I/O]] lets input and output [[Peripheral|devices]] be treated the same as memory.<ref>{{Citation |title=A New Architecture for Mini-Computers – The DEC PDP-11 |author-first1=C. Gordon |author-last1=Bell |author-link1=Gordon Bell |author-first2=R. |author-last2=Cady |author-first3=H. |author-last3=McFarland |author-first4=J. |author-last4=O'Laughlin |author-first5=R. |author-last5=Noonan |author-first6=W. |author-last6=Wulf |work=Spring Joint Computer Conference |pages=657–675 |date=1970 |url=http://research.microsoft.com/en-us/um/people/gbell/CGB%20Files/New%20Architecture%20PDP11%20SJCC%201970%20c.pdf}}.</ref> A single [[system bus]] could be used to provide a modular system with lower cost{{clarify|date=November 2015}}. This is sometimes called a "streamlining" of the architecture.<ref>{{Citation |title=The essentials of computer organization and architecture |author-first1=Linda |author-last1=Null |author-first2=Julia |author-last2=Lobur |publisher=[[Jones & Bartlett]] Learning |date=2010 |isbn=978-1-4496-0006-8 |edition=3rd |pages=36, 199–203 |url=https://books.google.com/books?id=f83XxoBC_8MC&pg=PA36}}.</ref>
In subsequent decades, simple [[microcontrollers]] would sometimes omit features of the model to lower cost and size.
Larger computers added features for higher performance.