Proprietary hardware is

computer hardware Computer hardware includes the physical parts of a computer, such as the computer case, case, central processing unit (CPU), Computer monitor, monitor, Computer mouse, mouse, Computer keyboard, keyboard, computer data storage, graphics card, so ...

whose

interface Interface or interfacing may refer to: Academic journals * Interface (journal), ''Interface'' (journal), by the Electrochemical Society * ''Interface, Journal of Applied Linguistics'', now merged with ''ITL International Journal of Applied Lin ...

is controlled by the

proprietor Ownership is the state or fact of exclusive rights and control over property, which may be any asset, including an object, land or real estate, intellectual property, or until the nineteenth century, slaves, human beings. Ownership involves multi ...

, often under

patent A patent is a type of intellectual property Intellectual property (IP) is a category of property Property is a system of rights that gives people legal control of valuable things, and also refers to the valuable things themselves. Depe ...

patent

or trade-secret protection. Historically, most early computer hardware was designed as proprietary until the 1980s, when

IBM PC The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first computer released in the IBM PC model line and the basis for the IBM PC compatible IBM PC compatible computers are similar to the original IBM PC The IBM ...

changed this paradigm. Earlier, in the 1970s, many vendors tried to challenge IBM's monopoly in the

mainframe computer A mainframe computer, informally called a mainframe or big iron, is a computer used primarily by large organizations for critical applications like bulk data processing for tasks such as census, censuses, industry and consumer statistics, ent ...

market by

reverse engineering Reverse engineering (also known as backwards engineering or back engineering) is a process or method through the application of which one attempts to understand through deductive reasoning Deductive reasoning, also deductive logic, is the process ...

and producing hardware components electrically compatible with expensive equipment and (usually) able to run the same software. Those vendors were nicknamed ''

plug compatible Plug compatible refers to "hardware that is designed to perform exactly like another vendor's product." The term PCM was originally applied to manufacturers who made replacements for IBM peripherals. Later this term was used to refer to IBM-compatib ...

manufacturers'' (PCMs).

See also