The lights are on
Member - Level 2
Click here to learn more about our points system.
A central processing unit (CPU), also referred to as a central processor unit, is the hardware within a computer that carries out the instructions of a computer program by performing the basic arithmetical, logical, and input/output operations of the system. The term has been in use in the computer industry at least since the early 1960s. The form, design,
and implementation of CPUs have changed over the course of their
history, but their fundamental operation remains much the same.
A computer can have more than one CPU; this is called multiprocessing. Some integrated circuits (ICs) can contain multiple CPUs on a single chip; those ICs are called multi-core processors.
Two typical components of a CPU are the arithmetic logic unit (ALU), which performs arithmetic and logical operations, and the control unit (CU), which extracts instructions from memory and decodes and executes them, calling on the ALU when necessary.
Not all computational systems rely on a central processing unit. An array processor or vector processor has multiple parallel computing elements, with no one unit considered the "center". In the distributed computing model, problems are solved by a distributed interconnected set of processors.
XL stands for eXtensible Language. It is a computer programming language designed to support concept programming.
XL features programmer-reconfigurable syntax and semantics. Compiler plug-ins can be used to add new features to the language. A base set of plug-ins implements a relatively standard imperative language. Programmers can write their own plug-ins to implement application-specific notations, such as symbolic differentiation, which can then be used similarly to built-in language features.