HeadRoom is a

DOS DOS is shorthand for the MS-DOS and IBM PC DOS family of operating systems. DOS may also refer to: Computing * Data over signalling (DoS), multiplexing data onto a signalling channel * Denial-of-service attack (DoS), an attack on a communicatio ...

context switching In computing, a context switch is the process of storing the state of a process or thread, so that it can be restored and resume execution at a later point, and then restoring a different, previously saved, state. This allows multiple processes ...

and multitasking memory manager produced by Helix Software Company in the late 1980s and early 1990s. HeadRoom managed multiple

terminate-and-stay-resident program A terminate-and-stay-resident program (commonly TSR) is a computer program running under DOS that uses a system call to return control to DOS as though it has finished, but remains in computer memory so it can be reactivated later. This technique ...

s (TSRs) and was the first TSR manager to allow sharing of

address space In computing, an address space defines a range of discrete addresses, each of which may correspond to a network host, peripheral device, disk sector, a memory cell or other logical or physical entity. For software programs to save and retrieve st ...

and

interrupts In digital computers, an interrupt (sometimes referred to as a trap) is a request for the processor to ''interrupt'' currently executing code (when permitted), so that the event can be processed in a timely manner. If the request is accepted, ...

among TSRs in DOS. HeadRoom v1.0 was released in September 1988. In April 1989, Helix Software released HeadRoom v1.1 together with the "HeadRoom Network Extensions." This version added support for network communications processes. The HeadRoom Network Extensions intercepted and buffered

NETBIOS NetBIOS () is an acronym for Network Basic Input/Output System. It provides services related to the session layer of the OSI model allowing applications on separate computers to communicate over a local area network. As strictly an API, NetB ...

and

TCP/IP The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the set of communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suit ...

communications Communication (from la, communicare, meaning "to share" or "to be in relation with") is usually defined as the transmission of information. The term may also refer to the message communicated through such transmissions or the field of inquir ...

requests, allowing HeadRoom to manage network communications software such as

mainframe 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 censuses, industry and consumer statistics, enterprise ...

Terminal Emulator A terminal emulator, or terminal application, is a computer program that emulates a video terminal within some other display architecture. Though typically synonymous with a shell or text terminal, the term ''terminal'' covers all remote termin ...

s and e-mail programs. The background communications of these programs would continue while the programs were swapped out. HeadRoom would reactivate the swapped-out programs when activity occurred on the NETBIOS or TCP/IP sockets. In October 1989, Helix Software released HeadRoom v2.0 which included support for

Microsoft Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

and

LIM EMS In DOS memory management, expanded memory is a system of bank switching that provided additional memory to DOS programs beyond the limit of conventional memory (640 KiB). ''Expanded memory'' is an umbrella term for several incompatible techn ...

v4.0. Starting in March 1990, this version of HeadRoom was bundled with

AST Research AST Research, Inc., later doing business as AST Computer, was a personal computer manufacturer. It was founded in 1980 in Irvine, California by Albert Wong, Safi Qureshey, and Thomas Yuen, as an initialism of their first names. In the 1980s, AS ...

RAMpage, RAMpage Plus and SixPack memory expansion boards. In June 1990, Helix Software licensed technology from Headroom to

Digital Communications Associates Digital Communication Associates, Inc. (DCA), was a company in the computer and telecommunications industry, located in Alpharetta, Georgia, United States. Overview Digital Communications Associates was founded by John Alderman, who led the compan ...

for use with their

IRMA board Irma may refer to: People * Irma (name), a female given name * Irma (singer), full name Irma Pany, a Cameroonian female singer-songwriter Places * Irma, Alberta, Canada, a village * Irma, Lombardy, Italy, a ''comune'' * Irma, Wisconsin, USA, a ...

s and IRMALan software. In January 1991, Helix released the final version of Headroom, v2.03 and thereafter incorporated HeadRoom's features into its Netroom LAN memory manager, a decision which caused market confusion.

References

{{Reflist, refs= {{cite journal, title=Headroom One-Ups Software Carousel With Memory-Management Innovation , url=https://books.google.com/books?id=9wwQdu9dei0C&pg=PA38, first=Edward, last=Mendelson, author-link=Edward Mendelson, page=38, accessdate=28 April 2015, date=28 Feb 1989 {{cite patent , country = US , number = 5167030 , status = patent {{cite patent , country = US , number = 5371871 , status = patent {{cite journal, title=Headroom Software Update Swaps Out LAN Programs, url=https://books.google.com/books?id=njAEAAAAMBAJ&pg=PT13, first=Jeff, last=Ansus, page=14, accessdate=28 April 2015, date=22 May 1989 {{cite journal, title=Headroom Allows Users To Swap Out Programs With No RAM Overhead, url=https://books.google.com/books?id=pTAEAAAAMBAJ&pg=PP16, first=Mark, last=Brownstein, page=16, accessdate=28 April 2015, date=23 Oct 1989 {{cite magazine, title=SixPak 286 , url=https://books.google.com/books?id=1DsEAAAAMBAJ&pg=PT32, magazine=InfoWorld, page=33, accessdate=28 April 2015, date=26 Mar 1990 {{cite journal, title=Industry Briefs , url=https://books.google.com/books?id=QB0EAAAAMBAJ&pg=PA9, page=9, accessdate=28 April 2015, date=30 Jun 1990 {{cite journal, title=Best Utilities, url=https://books.google.com/books?id=XNt4ttAFAiwC&pg=PA134, first=Rick, last=Ayre, accessdate=29 Apr 2015, date=14 September 1993, page=139 DOS memory management