computing Computing is any goal-oriented activity requiring, benefiting from, or creating computer, computing machinery. It includes the study and experimentation of algorithmic processes, and the development of both computer hardware, hardware and softw ...

, sys is a

command Command may refer to: Computing * Command (computing), a statement in a computer language * command (Unix), a Unix command * COMMAND.COM, the default operating system shell and command-line interpreter for DOS * Command key, a modifier key on A ...

used in many

operating system An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

command-line A command-line interface (CLI) is a means of interacting with software via commands each formatted as a line of text. Command-line interfaces emerged in the mid-1960s, on computer terminals, as an interactive and more user-friendly alternativ ...

shells and also in

Microsoft BASIC Microsoft BASIC is the foundation software product of the Microsoft company and evolved into a line of BASIC interpreters and compiler(s) adapted for many different microcomputers. It first appeared in 1975 as Altair BASIC, which was the first v ...

DOS, Windows, etc.

SYS is an external command of

Seattle Computer Products Seattle Computer Products (SCP) was a Tukwila, Washington, microcomputer hardware company which was one of the first manufacturers of computer systems based on the 16-bit Intel 8086 processor. Founded in 1978, SCP began shipping its first S ...

86-DOS 86-DOS (known internally as QDOS, for Quick and Dirty Operating System) is a discontinued operating system developed and marketed by Seattle Computer Products (SCP) for its Intel 8086-based computer kit. 86-DOS shared a few of its commands wi ...

Microsoft Microsoft Corporation is an American multinational corporation and technology company, technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the History of personal computers#The ear ...

MS-DOS MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few op ...

IBM International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...

PC DOS PC or pc may refer to: Arts and entertainment * Player character or playable character, a fictional character controlled by a human player, usually in role-playing games or computer games * '' Port Charles'', an American daytime TV soap opera * ...

Digital Research Digital Research, Inc. (DR or DRI) was a privately held American software company created by Gary Kildall to market and develop his CP/M operating system and related 8-bit, 16-bit and 32-bit systems like MP/M, Concurrent DOS, FlexOS, Multiuser ...

FlexOS FlexOS is a discontinued modular real-time multiuser multitasking operating system ( RTOS) designed for computer-integrated manufacturing, laboratory, retail and financial markets. Developed by Digital Research's Flexible Automation Business ...

Toshiba is a Japanese multinational electronics company headquartered in Minato, Tokyo. Its diversified products and services include power, industrial and social infrastructure systems, elevators and escalators, electronic components, semiconductors ...

4690 OS 4690 Operating System (sometimes shortened to 4690 OS or 4690) is a specially designed point of sale (POS) operating system, originally sold by IBM. In 2012, IBM sold its retail business, including this product, to Toshiba, which assumed support. ...

PTS-DOS PTS-DOS (aka PTS/DOS) is a disk operating system, a DOS clone, developed in Russia by PhysTechSoft and Paragon Technology Systems. History and versions PhysTechSoft was formed in 1991 in Moscow, Russia by graduates and members of MIPT, inf ...

Itautec Itautec is a Brazilian electronics company founded in 1979. It is part of Itaúsa, a Brazilian business group. Itautec is an ATM, kiosk, and computer manufacturer in the Brazilian and South American markets. The company also has a key role i ...

/ Scopus Tecnologia SISNE plus, and Microsoft

Windows 9x Windows 9x is a generic term referring to a line of discontinued Microsoft Windows operating systems released from 1995 to 2000 and supported until 2006, which were based on the kernel introduced in Windows 95 and modified in succeeding version ...

operating systems. It is used to make an already formatted medium bootable. It will install a

boot sector A boot sector is the disk sector, sector of a persistent data storage device (e.g., hard disk, floppy disk, optical disc, etc.) which contains machine code to be loaded into random-access memory (RAM) and then executed by a computer system's bui ...

capable of booting the operating system into the first logical sector of the volume. Further, it will copy the principal DOS system files, that is, the DOS-

BIOS In computing, BIOS (, ; Basic Input/Output System, also known as the System BIOS, ROM BIOS, BIOS ROM or PC BIOS) is a type of firmware used to provide runtime services for operating systems and programs and to perform hardware initialization d ...

( IO.SYS or IBMBIO.COM) and the DOS kernel ( MSDOS.SYS or IBMDOS.COM) into the root directory of the target. Due to restrictions in the implementation of the

boot loader A bootloader, also spelled as boot loader or called bootstrap loader, is a computer program that is responsible for booting a computer and booting an operating system. If it also provides an interactive menu with multiple boot choices then it's o ...

s in the boot sector and DOS' IO system, these two files must reside in the first two directory entries and be stored at the beginning of the data area under MS-DOS and PC DOS. Depending on version, the whole files or only a varying number of sectors of the DOS-BIOS (down to only three sectors in modern issues of DOS) will have to be stored in one consecutive part. SYS will try to physically rearrange other files on the medium in order to make room for these files in their required locations. This is why SYS needs to bypass the filesystem driver in the running operating system. Other DOS derivatives such as

DR-DOS DR-DOS is a disk operating system for IBM PC compatibles, originally developed by Gary A. Kildall's Digital Research, Inc. and derived from Concurrent PC DOS 6.0, which was an advanced successor of CP/M-86. Upon its introduction in 198 ...

do not have any such restrictions imposed by the design of the boot loaders, therefore under these systems, SYS will install a DR-DOS boot sector, which is capable of mounting the filesystem, and can then simply copy the two system files into the root directory of the target. SYS will also copy the

command line A command-line interface (CLI) is a means of interacting with software via command (computing), commands each formatted as a line of text. Command-line interfaces emerged in the mid-1960s, on computer terminals, as an interactive and more user ...

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses Science Biology * Seashell, a hard outer layer of a marine ani ...

( COMMAND.COM) into the root directory. The

can be applied to hard drives and

floppy disk A floppy disk or floppy diskette (casually referred to as a floppy, a diskette, or a disk) is a type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined with a ...

s to repair or create a boot sector. Although an article on Microsoft's website says the SYS command was introduced in

version 2.0, this is incorrect. SYS actually existed in

0.3 already. According to ''The MS-DOS Encyclopedia'', the command was licensed to

as part of the first version of MS-DOS, and as such it was part of MS-DOS/PC DOS from the very beginning (

IBM PC DOS IBM PC DOS (an acronym for IBM Personal Computer Disk Operating System),Formally known as "The IBM Personal Computer DOS" from versions 1.0 through 3.30, as reported in those versions' respective COMMAND.COM outputs also known as PC DOS or IBM ...

1.0 and MS-DOS 1.25). DR DOS 6.0 includes an implementation of the command.DR DOS 6.0 User Guide Optimisation and Configuration Tips
/ref>

Syntax

The command

syntax In linguistics, syntax ( ) is the study of how words and morphemes combine to form larger units such as phrases and sentences. Central concerns of syntax include word order, grammatical relations, hierarchical sentence structure (constituenc ...

is: SYS rive1:path] drive2: Arguments: * rive1:path] – The location of the system files *drive2: – The drive to which the files will be copied

Example

C:\>sys a:

Microsoft BASIC

SYS is also a command in Microsoft BASIC used to execute a

machine language In computer programming, machine code is computer code consisting of machine language instructions, which are used to control a computer's central processing unit (CPU). For conventional binary computers, machine code is the binaryOn nonb ...

program in memory. The command took the form SYS n where ''n'' is a

memory location In computing, a memory address is a reference to a specific memory location in memory used by both software and hardware. These addresses are fixed-length sequences of digits, typically displayed and handled as unsigned integers. This numeric ...

where the executable code starts.

Home computer Home computers were a class of microcomputers that entered the market in 1977 and became common during the 1980s. They were marketed to consumers as affordable and accessible computers that, for the first time, were intended for the use of a s ...

platforms typically publicised dozens of

entry point In computer programming, an entry point is the place in a program where the execution of a program begins, and where the program has access to command line arguments. To start a program's execution, the loader or operating system passes co ...

s to built-in routines (such as Commodore's

KERNAL KERNAL is Commodore's name for the ROM-resident operating system core in its 8-bit home computers; from the original PET of 1977, followed by the extended but related versions used in its successors: the VIC-20, Commodore 64, Plus/4, Commodore ...

) that were used by programmers and users to access functionality not easily accessible through BASIC.

References

External links

MS-DOS and Windows command line sys commandOpen source SYS implementation that comes with MS-DOS v2.0
{{Windows commands External DOS commands Microcomputer software Microsoft free software BASIC commands