Merge

Merge, merging, or merger may refer to:

Concepts

Computer science

Merge (software)

Merge is a software system which allows a user to run DOS/Windows 3.1 on SCO UNIX, in an 8086 virtual machine.

History

Merge was originally developed to run DOS under UNIX System V Release 2 on an AT&T 6300 Plus personal computer. Development of the virtual machine began in late 1984, and AT&T announced the availability of the machine on October 9, 1985, referring to the bundled Merge software as SimulTask. (The PC6300 Plus shipped with MS-DOS in 1985 though, because its Unix System V distribution was not ready until the end March 1986.) Merge was developed by engineers at Locus Computing Corporation, with collaboration from AT&T hardware and software engineers, particularly on aspects of the system that were specific to the 6300 Plus (in contrast to a standard PC/AT).

The AT&T 6300 Plus contained an Intel 80286 processor, which did not include the support for 8086 virtual machines (virtual 8086 mode) found in the Intel 80386 and later processors in the x86 family. On the 80286, the DOS program had to run in realmode. The 6300 Plus was designed with special hardware on the bus that would suppress and capture bus cycles from the DOS program if they were directed toward addresses not assigned for direct access by the DOS virtual machine. Various system registers, such as the programmable interrupt controller, and the video controller, had to be emulated in software for the DOS process, and a watchdog timer was implemented to recover from DOS programs that would clear the interrupt flag and then hang for too long. The hardware used the Non Maskable Interrupt (NMI) to take control back to the emulation code. More detail may be seen in the patent referenced in the External Links below.

Merge (linguistics)

Merge (usually capitalized) is one of the basic operations in the Minimalist Program, a leading approach to generative syntax, when two syntactic objects are combined to form a new syntactic unit (a set). Merge also has the property of recursion in that it may apply to its own output: the objects combined by Merge are either lexical items or sets that were themselves formed by Merge. This recursive property of Merge has been claimed to be a fundamental characteristic that distinguishes language from other cognitive faculties. As Noam Chomsky (1999) puts it, Merge is "an indispensable operation of a recursive system ... which takes two syntactic objects A and B and forms the new object G={A,B}" (p. 2).

Mechanisms of Merge

Within the Minimalist Program, syntax is derivational, and Merge is the structure-building operation. Merge is assumed to have certain formal properties constraining syntactic structure, and is implemented with specific mechanisms.

Binary branching

Merge takes two objects α and β and combines them, creating a binary structure.