A desktop replacement computer (DTR) is a

personal computer A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or te ...

that provides the full capabilities of a

desktop computer A desktop computer (often abbreviated desktop) is a personal computer designed for regular use at a single location on or near a desk due to its size and power requirements. The most common configuration has a case that houses the power supply ...

while remaining mobile. They are often larger, bulkier

laptop A laptop, laptop computer, or notebook computer is a small, portable personal computer (PC) with a screen and alphanumeric keyboard. Laptops typically have a clam shell form factor with the screen mounted on the inside of the upper li ...

s or in some cases 2-in-1 PCs with a

tablet Tablet may refer to: Medicine * Tablet (pharmacy), a mixture of pharmacological substances pressed into a small cake or bar, colloquially called a "pill" Computing * Tablet computer, a mobile computer that is primarily operated by touching the ...

-like form factor and interface. Because of their increased size, this class of computer usually includes more powerful components and a larger display than generally used in smaller portable computers and can have a relatively limited battery capacity (or none at all). Some use a limited range of desktop components to provide better performance at the expense of battery life. These are sometimes called desknotes, a blend of "desktop" and "notebook", though the term is also applied to desktop replacement computers in general. Other names being monster notebooks or musclebooks in reference to muscle cars.

Origins

Micro ordinateur portable le PORTAL de R2E CCMC

The forerunners of the desktop replacement were the

portable computer A portable computer is a computer designed to be easily moved from one place to another and included a display and keyboard together, with a single plug, much like later desktop computers called '' all-in-ones'' (AIO), that integrate the s ...

s of the early to mid-1980s, such as the

Portal Portal often refers to: *Portal (architecture), an opening in a wall of a building, gate or fortification, or the extremities (ends) of a tunnel Portal may also refer to: Arts and entertainment Gaming * ''Portal'' (series), two video games ...

R2E CCMC, the

Osborne 1 The Osborne 1 is the first commercially successful portable computer, released on April 3, 1981 by Osborne Computer Corporation. It weighs , cost US$1,795, and runs the CP/M 2.2 operating system. It is powered from a wall socket, as it has no ...

Kaypro II Kaypro Corporation was an American home and personal computer manufacturer based out of San Diego in the 1980s. The company was founded by Non-Linear Systems (NLS) to compete with the popular Osborne 1 portable microcomputer. Kaypro produced a ...

, the

Compaq Portable The Compaq Portable was an early portable computer which was one of the first IBM PC compatible systems. It was Compaq Computer Corporation's first product, to be followed by others in the Compaq Portable series and later Compaq Deskpro serie ...

and the

Commodore Commodore may refer to: Ranks * Commodore (rank), a naval rank ** Commodore (Royal Navy), in the United Kingdom ** Commodore (United States) ** Commodore (Canada) ** Commodore (Finland) ** Commodore (Germany) or ''Kommodore'' * Air commodore ...

Executive 64 (SX-64) computers. These computers contained the

CPU A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, a ...

, display, floppy disk drive and

power supply A power supply is an electrical device that supplies electric power to an electrical load. The main purpose of a power supply is to convert electric current from a source to the correct voltage, current, and frequency to power the load. As ...

all in a single briefcase-like enclosure. Similar in performance to the desktop computers of the era, they were easily transported and came with an attached keyboard that doubled as a protective cover when not in use. They could be used wherever space and an electrical outlet were available, as they had no battery. The development of the

form factor gave new impetus to portable computer development. Many early laptops were feature-limited in the interest of portability, requiring such mobility-limiting accessories as external floppy drives or clip-on

trackball A trackball is a pointing device consisting of a ball held by a socket containing sensors to detect a rotation of the ball about two axes—like an upside-down ball mouse with an exposed protruding ball. Users roll the ball to position the o ...

pointing devices. One of the first laptops that could be used as a standalone computer was the EUROCOM 2100 based on Intel's 8088 CPU architecture, it duplicated the functionality of the desktop models without requiring an external

docking station In computing, a docking station or port replicator (hub) or dock provides a simplified way to ''plug-in'' a mobile device, such as a laptop, to common peripherals. Because a wide range of dockable devices—from mobile phones to wireless mou ...

. The development of the modern desktop replacement computer came with the realization that many laptops were used in a semi-permanent location, often remaining connected to an external power source at all times. This suggested that a market existed for a laptop-style computer that would take advantage of the user's reduced need for portability, allowing for higher-performance components, greater expandability, and higher-quality displays. Desktop replacement computers are also often used with a port replicator, to full enjoy the desktop comfort.

Design features

Modern desktop replacements generally perform better than traditional laptop-style computers as their size allows the inclusion of more powerful components. The larger body means more efficient heat-dissipation, allowing manufacturers to use components that would otherwise overheat during normal use. Furthermore, their increased size allows for more

modularity Broadly speaking, modularity is the degree to which a system's components may be separated and recombined, often with the benefit of flexibility and variety in use. The concept of modularity is used primarily to reduce complexity by breaking a sy ...

, which allows for a greater expandability and features, as well as larger and brighter displays. However, these advantages generally come at a price premium, with many computers in this class costing as much as two desktop computers with similar specifications. Using a laptop form factor, however, desktop replacements still often suffer from limitations similar to those of more mobile laptops. They usually lack the ability to accept standard PCIe expansion cards, somewhat limiting their expandability. While desktop replacements can offer better cooling than other laptops, they rarely dissipate heat efficiently enough to allow for high-end desktop-class components, and thus may not reach the same performance levels as

s. Desktop replacement computers are, with a few exceptions, difficult to upgrade compared to desktop computers, with many of their major components (such as the display) integral to the design of the machine, and others (such as the

and GPU) often being hard to access and replace.Upgrading and Repairing Laptops
accessed April 2010 A small segment of desktop replacements do not include a battery as a standard feature, while some do not include ExpressCard support. They have the same limitations on serviceability as laptops, and can rarely use identical components to a desktop computer.

References

{{Computer sizes Laptops Portable computers

Origins

Design features

See also

References