Editing Lisp machine (section)

===Historical context===
[[Artificial intelligence]] (AI) computer programs of the 1960s and 1970s intrinsically required what was then considered a huge amount of computer power, as measured in processor time and memory space. The power requirements of AI research were exacerbated by the Lisp symbolic programming language, when commercial hardware was designed and optimized for [[Assembly language|assembly]]- and [[Fortran]]-like programming languages. At first, the cost of such computer hardware meant that it had to be shared among many users. As [[integrated circuit]] technology shrank the size and cost of computers in the 1960s and early 1970s, and the memory needs of AI programs began to exceed the [[address space]] of the most common research computer, the [[Digital Equipment Corporation]] (DEC) [[PDP-10]], researchers considered a new approach: a computer designed specifically to develop and run large artificial intelligence programs, and tailored to the semantics of the [[Lisp (programming language)|Lisp]] language. To keep the [[operating system]] (relatively) simple, these machines would often not be shared, but would be dedicated to a single user at a time.{{Citation needed|date=October 2009}}