Editing PDP-8 (section)

==Architectural significance==
The PDP-8 combines low cost,<ref name=LowPrice/> simplicity, expandability, and careful engineering for value. The greatest historical significance was that the PDP-8's low cost and high volume made a computer available to many new customers for many new uses. Its continuing significance is as a historical example of value-engineered<ref name=Handbook.8I>{{cite book
|title=Small Computer Handbook, NEW PDP 8/I edition (Forward)
|publisher=[[Digital Equipment Corporation]] |date=1968}}</ref> computer design.

The low complexity brought other costs. It made programming cumbersome, as is seen in the examples in this article and from the discussion of "pages" and "fields". Much of one's code performed the required mechanics, as opposed to setting out the algorithm. For example, subtracting a number involves computing its two's complement then adding it; writing a conditional jump involves writing a conditional skip around the jump, the skip coding the condition negative to the one desired. Some ambitious programming projects failed to fit in memory or developed design defects that could not be solved. For example, as noted [[#Subroutines|below]], inadvertent recursion of a subroutine produces defects that are difficult to trace to the subroutine in question.

As design advances reduced the costs of logic and memory, the programmer's time became relatively more important.<ref>{{cite magazine |magazine=PC Magazine |date=October 29, 1985
|title=Benchmarking the Languages |volume=4 |issue=22 |page=112 |url=https://books.google.com/books?id=jBnPebByBGkC&q=%22the%20best%20use%20of%20today%27s%20most%20precious%20computer%20resource%3A%20a%20programmer%27s%20time%22&pg=PA112|quote=the best use of today's most precious computer resource: a programmer's time ...}}</ref> Subsequent computer designs emphasized ease of programming, typically using larger and more intuitive instruction sets.<ref>a phrase used in Section 1.1 of "Introduction to the Central Processing Unit (CPU)" of a 2007 document about a Texas Instruments microcomputer.{{cite web |url=http://www.ti.com.cn/cn/lit/ug/spru430f/spru430f.pdf |title=TMS320C28x CPU and Instruction Set (Rev. F)}}</ref>

Eventually, most machine code was generated by [[compiler]]s and report generators.<ref>{{cite book |url=http://www.diku.dk/~torbenm/Basics/basics_lulu2.pdf |title=Basics of Compiler Design |author=Torben Ægidius Mogensen |date=August 20, 2010 |page=1 |quote=Another advantage of using a high-level level language is that the same program can be compiled to many different machine languages and, hence, be brought to run on many different machines.}}</ref> The [[reduced instruction set computer]] returned full-circle to the PDP-8's emphasis on a simple instruction set and achieving multiple actions in a single instruction cycle, in order to maximize execution speed, although the newer computers have much longer instruction words.