Proprietary software is software that grants its creator, publisher, or other rightsholder or rightsholder partner a legal monopoly by modern copyright and intellectual property law to exclude the recipient from freely sharing the software or modifying it, and—in some cases, as is the case with some patent-encumbered and EULA -bound software—from making use of the software on their own, thereby restricting their freedoms.
84-780: BCU may refer to: Computing [ edit ] BIOS configuration utility Bus Coupling Unit , an EIB/ KNX bus coupler IBM Balanced Configuration Unit Universities and libraries [ edit ] Bengaluru City University , formerly Bengaluru Central University, in Karnataka, India Bethune–Cookman University Birmingham City University Briar Cliff University Business and Computer University , Lebanon Cantonal and University Library of Lausanne , Switzerland (Bibliothèque cantonale et universitaire de Lausanne) Other uses [ edit ] Awad Bing language (ISO 639-2 code "bcu") Babish Culinary Universe ,
168-478: A de facto standard . The BIOS in older PCs initializes and tests the system hardware components ( power-on self-test or POST for short), and loads a boot loader from a mass storage device which then initializes a kernel . In the era of DOS , the BIOS provided BIOS interrupt calls for the keyboard, display, storage, and other input/output (I/O) devices that standardized an interface to application programs and
252-468: A network adapter attempts booting by a procedure that is defined by its option ROM or the equivalent integrated into the motherboard BIOS ROM. As such, option ROMs may also influence or supplant the boot process defined by the motherboard BIOS ROM. With the El Torito optical media boot standard , the optical drive actually emulates a 3.5" high-density floppy disk to the BIOS for boot purposes. Reading
336-476: A trade secret . Software can be made available with fewer restrictions on licensing or source-code access; software that satisfies certain conditions of freedom and openness is known as " free " or " open-source ." Since license agreements do not override applicable copyright law or contract law , provisions in conflict with applicable law are not enforceable. Some software is specifically licensed and not sold, in order to avoid limitations of copyright such as
420-507: A "mixed source" model including both free and non-free software in the same distribution. Most if not all so-called proprietary UNIX distributions are mixed source software, bundling open-source components like BIND , Sendmail , X Window System , DHCP , and others along with a purely proprietary kernel and system utilities. Some free software packages are also simultaneously available under proprietary terms. Examples include MySQL , Sendmail and ssh. The original copyright holders for
504-523: A February 21, 1997, internal Microsoft memo drafted for Bill Gates : Early versions of the iPhone SDK were covered by a non-disclosure agreement . The agreement forbade independent developers from discussing the content of the interfaces. Apple discontinued the NDA in October 2008. Any dependency on the future versions and upgrades for a proprietary software package can create vendor lock-in , entrenching
588-467: A Government Security Program (GSP) to allow governments to view source code and Microsoft security documentation, of which the Chinese government was an early participant. The program is part of Microsoft's broader Shared Source Initiative which provides source code access for some products. The Reference Source License (Ms-RSL) and Limited Public License (Ms-LPL) are proprietary software licenses where
672-602: A ROM chip) that contains a BIOS extension ROM. The motherboard BIOS typically contains code for initializing and bootstrapping integrated display and integrated storage. The initialization process can involve the execution of code related to the device being initialized, for locating the device, verifying the type of device, then establishing base registers, setting pointers , establishing interrupt vector tables, selecting paging modes which are ways for organizing available registers in devices, setting default values for accessing software routines related to interrupts , and setting
756-523: A SLIC can be preactivated with an OEM product key, and they verify an XML formatted OEM certificate against the SLIC in the BIOS as a means of self-activating (see System Locked Preinstallation , SLP). If a user performs a fresh install of Windows, they will need to have possession of both the OEM key (either SLP or COA) and the digital certificate for their SLIC in order to bypass activation. This can be achieved if
840-568: A YouTube cooking channel Banco Central del Uruguay , official name in Spanish of the Central Bank of Uruguay Basic command unit British Canoeing former name of British Canoe Union British Columbia United is a centre-right political party in the province of British Columbia, Canada IATA airport code for Bauchi State Airport , Nigeria Bumilangit Cinematic Universe , an Indonesian superhero franchise Topics referred to by
924-401: A copy can decide whether, and how much, to charge for a copy or related services. Proprietary software that comes for no cost is called freeware . Proponents of commercial proprietary software argue that requiring users to pay for software as a product increases funding or time available for the research and development of software. For example, Microsoft says that per-copy fees maximize
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#17327796070591008-608: A hard disk that is bootable, but sometimes there is a removable-media drive that has higher boot priority, so the user can cause a removable disk to be booted. In most modern BIOSes, the boot priority order can be configured by the user. In older BIOSes, limited boot priority options are selectable; in the earliest BIOSes, a fixed priority scheme was implemented, with floppy disk drives first, fixed disks (i.e., hard disks) second, and typically no other boot devices supported, subject to modification of these rules by installed option ROMs. The BIOS in an early PC also usually would only boot from
1092-564: A license for the Internet forum software vBulletin can modify the source for their own site but cannot redistribute it. This is true for many web applications, which must be in source code form when being run by a web server. The source code is covered by a non-disclosure agreement or a license that allows, for example, study and modification, but not redistribution. The text-based email client Pine and certain implementations of Secure Shell are distributed with proprietary licenses that make
1176-561: A message like "No bootable disk found"; some would prompt for a disk to be inserted and a key to be pressed to retry the boot process. A modern BIOS may display nothing or may automatically enter the BIOS configuration utility when the boot process fails. The environment for the boot program is very simple: the CPU is in real mode and the general-purpose and segment registers are undefined, except SS, SP, CS, and DL. CS:IP always points to physical address 0x07C00 . What values CS and IP actually have
1260-560: A monopoly position. Proprietary software may also have licensing terms that limit the usage of that software to a specific set of hardware. Apple has such a licensing model for macOS , an operating system which is limited to Apple hardware, both by licensing and various design decisions. This licensing model has been affirmed by the United States Court of Appeals for the Ninth Circuit . Proprietary software which
1344-547: A network device or a SCSI adapter) in a cooperative way, it can use the BIOS Boot Specification (BBS) API to register its ability to do so. Once the expansion ROMs have registered using the BBS APIs, the user can select among the available boot options from within the BIOS's user interface. This is why most BBS compliant PC BIOS implementations will not allow the user to enter the BIOS's user interface until
1428-422: A portion of the " upper memory area " (the part of the x86 real-mode address space at and above address 0xA0000) and runs each ROM found, in order. To discover memory-mapped option ROMs, a BIOS implementation scans the real-mode address space from 0x0C0000 to 0x0F0000 on 2 KB (2,048 bytes) boundaries, looking for a two-byte ROM signature : 0x55 followed by 0xAA. In a valid expansion ROM, this signature
1512-464: A reserved block of system RAM at addresses 0x00400–0x004FF with various parameters initialized during the POST. All memory at and above address 0x00500 can be used by the boot program; it may even overwrite itself. The BIOS ROM is customized to the particular manufacturer's hardware, allowing low-level services (such as reading a keystroke or writing a sector of data to diskette) to be provided in
1596-503: A simple boot loader in its ROM.) Versions of MS-DOS , PC DOS or DR-DOS contain a file called variously " IO.SYS ", " IBMBIO.COM ", "IBMBIO.SYS", or "DRBIOS.SYS"; this file is known as the "DOS BIOS" (also known as the "DOS I/O System") and contains the lower-level hardware-specific part of the operating system. Together with the underlying hardware-specific but operating system-independent "System BIOS", which resides in ROM , it represents
1680-481: A single user or computer. In some cases, software features are restricted during or after the trial period, a practice sometimes called crippleware . Proprietary software often stores some of its data in file formats that are incompatible with other software, and may also communicate using protocols which are incompatible. Such formats and protocols may be restricted as trade secrets or subject to patents . A proprietary application programming interface (API)
1764-621: A software licensing description table (SLIC), a digital signature placed inside the BIOS by the original equipment manufacturer (OEM), for example Dell . The SLIC is inserted into the ACPI data table and contains no active code. Computer manufacturers that distribute OEM versions of Microsoft Windows and Microsoft application software can use the SLIC to authenticate licensing to the OEM Windows Installation disk and system recovery disc containing Windows software. Systems with
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#17327796070591848-462: A software package may be ended to force users to upgrade and pay for newer versions ( planned obsolescence ). Sometimes another vendor or a software's community themselves can provide support for the software, or the users can migrate to either competing systems with longer support life cycles or to FOSS -based systems. Some proprietary software is released by their owner at end-of-life as open-source or source available software, often to prevent
1932-454: A standardized way to programs, including operating systems. For example, an IBM PC might have either a monochrome or a color display adapter (using different display memory addresses and hardware), but a single, standard, BIOS system call may be invoked to display a character at a specified position on the screen in text mode or graphics mode . The BIOS provides a small library of basic input/output functions to operate peripherals (such as
2016-425: A technical measure, such as product activation , a product key or serial number, a hardware key , or copy protection . Vendors may also distribute versions that remove particular features, or versions which allow only certain fields of endeavor, such as non-commercial, educational, or non-profit use. Use restrictions vary by license: Vendors typically distribute proprietary software in compiled form, usually
2100-406: A work of free software, even copyleft free software, can use dual-licensing to allow themselves or others to redistribute proprietary versions. Non-copyleft free software (i.e. software distributed under a permissive free software license or released to the public domain) allows anyone to make proprietary redistributions. Free software that depends on proprietary software is considered "trapped" by
2184-476: Is Windows 10 as Windows 11 requires a UEFI-compliant system (except for IoT Enterprise editions of Windows 11 since version 24H2 ). The term BIOS (Basic Input/Output System) was created by Gary Kildall and first appeared in the CP/M operating system in 1975, describing the machine-specific part of CP/M loaded during boot time that interfaces directly with the hardware . (A CP/M machine usually has only
2268-484: Is a software library interface "specific to one device or, more likely to a number of devices within a particular manufacturer's product range." The motivation for using a proprietary API can be vendor lock-in or because standard APIs do not support the device's functionality. The European Commission , in its March 24, 2004, decision on Microsoft's business practices, quotes, in paragraph 463, Microsoft general manager for C++ development Aaron Contorer as stating in
2352-406: Is bootable by attempting to load the first sector ( boot sector ). If the sector cannot be read, the BIOS proceeds to the next device. If the sector is read successfully, some BIOSes will also check for the boot sector signature 0x55 0xAA in the last two bytes of the sector (which is 512 bytes long), before accepting a boot sector and considering the device bootable. When a bootable device is found,
2436-501: Is different from Wikidata All article disambiguation pages All disambiguation pages BIOS#BCU In computing , BIOS ( / ˈ b aɪ ɒ s , - oʊ s / , BY -oss, -ohss ; Basic Input/Output System , also known as the System BIOS , ROM BIOS , BIOS ROM or PC BIOS ) is firmware used to provide runtime services for operating systems and programs and to perform hardware initialization during
2520-452: Is followed by a single byte indicating the number of 512-byte blocks the expansion ROM occupies in real memory, and the next byte is the option ROM's entry point (also known as its "entry offset"). If the ROM has a valid checksum, the BIOS transfers control to the entry address, which in a normal BIOS extension ROM should be the beginning of the extension's initialization routine. At this point,
2604-489: Is no longer marketed, supported or sold by its owner is called abandonware , the digital form of orphaned works . If the proprietor of a software package should cease to exist, or decide to cease or limit production or support for a proprietary software package, recipients and users of the package may have no recourse if problems are found with the software. Proprietors can fail to improve and support software because of business problems. Support for older or existing versions of
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2688-436: Is not synonymous with commercial software , although the two terms are sometimes used synonymously in articles about free software. Proprietary software can be distributed at no cost or for a fee, and free software can be distributed at no cost or for a fee. The difference is that whether proprietary software can be distributed, and what the fee would be, is at the proprietor's discretion. With free software, anyone who has
2772-556: Is not well defined. Some BIOSes use a CS:IP of 0x0000:0x7C00 while others may use 0x07C0:0x0000 . Because boot programs are always loaded at this fixed address, there is no need for a boot program to be relocatable. DL may contain the drive number, as used with interrupt 13h , of the boot device. SS:SP points to a valid stack that is presumably large enough to support hardware interrupts, but otherwise SS and SP are undefined. (A stack must be already set up in order for interrupts to be serviced, and interrupts must be enabled in order for
2856-471: Is performed each time the system is powered up. Without reprogrammable microcode, an expensive processor swap would be required; for example, the Pentium FDIV bug became an expensive fiasco for Intel as it required a product recall because the original Pentium processor's defective microcode could not be reprogrammed. Operating systems can update main processor microcode also. Some BIOSes contain
2940-541: Is rebooting. When interrupt 19h is called, the BIOS attempts to locate boot loader software on a "boot device", such as a hard disk , a floppy disk , CD , or DVD . It loads and executes the first boot software it finds, giving it control of the PC. The BIOS uses the boot devices set in Nonvolatile BIOS memory ( CMOS ), or, in the earliest PCs, DIP switches . The BIOS checks each device in order to see if it
3024-400: Is required for another party to use the software. In the case of proprietary software with source code available, the vendor may also prohibit customers from distributing their modifications to the source code. Shareware is closed-source software whose owner encourages redistribution at no cost, but which the user sometimes must pay to use after a trial period. The fee usually allows use by
3108-488: Is running. The interrupt vectors corresponding to the BIOS interrupts have been set to point at the appropriate entry points in the BIOS, hardware interrupt vectors for devices initialized by the BIOS have been set to point to the BIOS-provided ISRs, and some other interrupts, including ones that BIOS generates for programs to hook, have been set to a default dummy ISR that immediately returns. The BIOS maintains
3192-663: Is unique among PCs in having two ROM cartridge slots on the front. Cartridges in these slots map into the same region of the upper memory area used for option ROMs, and the cartridges can contain option ROM modules that the BIOS would recognize. The cartridges can also contain other types of ROM modules, such as BASIC programs, that are handled differently. One PCjr cartridge can contain several ROM modules of different types, possibly stored together in one ROM chip. The 8086 and 8088 start at physical address FFFF0h. The 80286 starts at physical address FFFFF0h. The 80386 and later x86 processors start at physical address FFFFFFF0h. When
3276-611: The CPU , chipset , RAM , motherboard , video card , keyboard , mouse , hard disk drive , optical disc drive and other hardware , including integrated peripherals . Early IBM PCs had a routine in the POST that would download a program into RAM through the keyboard port and run it. This feature was intended for factory test or diagnostic purposes. After the motherboard BIOS completes its POST, most BIOS versions search for option ROM modules, also called BIOS extension ROMs, and execute them. The motherboard BIOS scans for extension ROMs in
3360-574: The booting process (power-on startup). The firmware comes pre-installed on the computer's motherboard . The name originates from the Basic Input/Output System used in the CP/M operating system in 1975. The BIOS firmware was originally proprietary to the IBM PC ; it was reverse engineered by some companies (such as Phoenix Technologies ) looking to create compatible systems. The interface of that original system serves as
3444-425: The first-sale doctrine . The owner of proprietary software exercises certain exclusive rights over the software. The owner can restrict the use, inspection of source code, modification of source code, and redistribution. Vendors typically limit the number of computers on which software can be used, and prohibit the user from installing the software on extra computers. Restricted use is sometimes enforced through
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3528-468: The machine language understood by the computer's central processing unit . They typically retain the source code , or human-readable version of the software, often written in a higher level programming language . This scheme is often referred to as closed source. While most proprietary software is distributed without the source code, some vendors distribute the source code or otherwise make it available to customers. For example, users who have purchased
3612-423: The "first sector" of a CD-ROM or DVD-ROM is not a simply defined operation like it is on a floppy disk or a hard disk. Furthermore, the complexity of the medium makes it difficult to write a useful boot program in one sector. The bootable virtual floppy disk can contain software that provides access to the optical medium in its native format. If an expansion ROM wishes to change the way the system boots (such as from
3696-430: The 1980s under MS-DOS , when programmers observed that using the BIOS video services for graphics display were very slow. To increase the speed of screen output, many programs bypassed the BIOS and programmed the video display hardware directly. Other graphics programmers, particularly but not exclusively in the demoscene , observed that there were technical capabilities of the PC display adapters that were not supported by
3780-424: The BIOS after completing its initialization process. Once (and if) an option ROM returns, the BIOS continues searching for more option ROMs, calling each as it is found, until the entire option ROM area in the memory space has been scanned. It is possible that an option ROM will not return to BIOS, pre-empting the BIOS's boot sequence altogether. After the POST completes and, in a BIOS that supports option ROMs, after
3864-601: The BIOS to carry out most input/output tasks within the PC. Calling real mode BIOS services directly is inefficient for protected mode (and long mode ) operating systems. BIOS interrupt calls are not used by modern multitasking operating systems after they initially load. In the 1990s, BIOS provided some protected mode interfaces for Microsoft Windows and Unix-like operating systems, such as Advanced Power Management (APM), Plug and Play BIOS , Desktop Management Interface (DMI), VESA BIOS Extensions (VBE), e820 and MultiProcessor Specification (MPS). Starting from
3948-408: The BIOS transfers control to the loaded sector. The BIOS does not interpret the contents of the boot sector other than to possibly check for the boot sector signature in the last two bytes. Interpretation of data structures like partition tables and BIOS Parameter Blocks is done by the boot program in the boot sector itself or by other programs loaded through the boot process. A non-disk device such as
4032-630: The BIOS. Code in option ROMs runs before the BIOS boots the operating system from mass storage . These ROMs typically test and initialize hardware, add new BIOS services, or replace existing BIOS services with their own services. For example, a SCSI controller usually has a BIOS extension ROM that adds support for hard drives connected through that controller. An extension ROM could in principle contain operating system, or it could implement an entirely different boot process such as network booting . Operation of an IBM-compatible computer system can be completely changed by removing or inserting an adapter card (or
4116-625: The Free Software Foundation. This includes software written only for Microsoft Windows, or software that could only run on Java , before it became free software. Most of the software is covered by copyright which, along with contract law , patents , and trade secrets , provides legal basis for its owner to establish exclusive rights. A software vendor delineates the specific terms of use in an end-user license agreement (EULA). The user may agree to this contract in writing, interactively on screen ( clickwrap ), or by opening
4200-717: The IBM BIOS and could not be taken advantage of without circumventing it. Since the AT-compatible BIOS ran in Intel real mode , operating systems that ran in protected mode on 286 and later processors required hardware device drivers compatible with protected mode operation to replace BIOS services. In modern PCs running modern operating systems (such as Windows and Linux ) the BIOS interrupt calls are used only during booting and initial loading of operating systems. Before
4284-500: The analogue to the " CP/M BIOS ". The BIOS originally proprietary to the IBM PC has been reverse engineered by some companies (such as Phoenix Technologies ) looking to create compatible systems. With the introduction of PS/2 machines, IBM divided the System BIOS into real- and protected-mode portions. The real-mode portion was meant to provide backward compatibility with existing operating systems such as DOS, and therefore
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#17327796070594368-510: The boot sequence by inserting its own boot actions into it, by preventing the BIOS from detecting certain devices as bootable, or both. Before the BIOS Boot Specification was promulgated, this was the only way for expansion ROMs to implement boot capability for devices not supported for booting by the native BIOS of the motherboard. The user can select the boot priority implemented by the BIOS. For example, most computers have
4452-416: The box containing the software ( shrink wrap licensing ). License agreements are usually not negotiable . Software patents grant exclusive rights to algorithms, software features, or other patentable subject matter , with coverage varying by jurisdiction. Vendors sometimes grant patent rights to the user in the license agreement. The source code for a piece of proprietary software is routinely handled as
4536-459: The card is not supported by the motherboard BIOS and the card needs to be initialized or made accessible through BIOS services before the operating system can be loaded (usually this means it is required in the boot process). An additional advantage of ROM on some early PC systems (notably including the IBM PCjr) was that ROM was faster than main system RAM. (On modern systems, the case is very much
4620-776: The chip from the motherboard. This allows easy, end-user updates to the BIOS firmware so new features can be added or bugs can be fixed, but it also creates a possibility for the computer to become infected with BIOS rootkits . Furthermore, a BIOS upgrade that fails could brick the motherboard. Unified Extensible Firmware Interface (UEFI) is a successor to the legacy PC BIOS, aiming to address its technical limitations. UEFI firmware may include legacy BIOS compatibility to maintain compatibility with operating systems and option cards that do not support UEFI native operation. Since 2020, all PCs for Intel platforms no longer support Legacy BIOS. The last version of Microsoft Windows to officially support running on PCs which use legacy BIOS firmware
4704-492: The computer, and if it was lost the system settings could not be changed. The same applied in general to computers with an EISA bus, for which the configuration program was called an EISA Configuration Utility (ECU). A modern Wintel -compatible computer provides a setup routine essentially unchanged in nature from the ROM-resident BIOS setup utilities of the late 1990s; the user can configure hardware options using
4788-440: The device's configuration using default values. In addition, plug-in adapter cards such as SCSI , RAID , network interface cards , and video cards often include their own BIOS (e.g. Video BIOS ), complementing or replacing the system BIOS code for the given component. Even devices built into the motherboard can behave in this way; their option ROMs can be a part of the motherboard BIOS. An add-in card requires an option ROM if
4872-485: The expansion ROMs have finished executing and registering themselves with the BBS API. Also, if an expansion ROM wishes to change the way the system boots unilaterally, it can simply hook interrupt 19h or other interrupts normally called from interrupt 19h, such as interrupt 13h, the BIOS disk service, to intercept the BIOS boot process. Then it can replace the BIOS boot process with one of its own, or it can merely modify
4956-416: The extension ROM code takes over, typically testing and initializing the hardware it controls and registering interrupt vectors for use by post-boot applications. It may use BIOS services (including those provided by previously initialized option ROMs) to provide a user configuration interface, to display diagnostic information, or to do anything else that it requires. An option ROM should normally return to
5040-465: The first floppy disk drive or the first hard disk drive, even if there were two drives installed. On the original IBM PC and XT, if no bootable disk was found, the BIOS would try to start ROM BASIC with the interrupt call to interrupt 18h . Since few programs used BASIC in ROM, clone PC makers left it out; then a computer that failed to boot from a disk would display "No ROM BASIC" and halt (in response to interrupt 18h). Later computers would display
5124-403: The keyboard and video display. The modern Wintel machine may store the BIOS configuration settings in flash ROM, perhaps the same flash ROM that holds the BIOS itself. Peripheral cards such as hard disk drive host bus adapters and video cards have their own firmware, and BIOS extension option ROM code may be a part of the expansion card firmware; that code provides additional capabilities in
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#17327796070595208-654: The keyboard, rudimentary text and graphics display functions and so forth). When using MS-DOS, BIOS services could be accessed by an application program (or by MS-DOS) by executing an interrupt 13h interrupt instruction to access disk functions, or by executing one of a number of other documented BIOS interrupt calls to access video display , keyboard , cassette, and other device functions. Operating systems and executive software that are designed to supersede this basic firmware functionality provide replacement software interfaces to application software. Applications can also provide these services to themselves. This began even in
5292-447: The late 1960s, computers—especially large and expensive mainframe computers , machines in specially air-conditioned computer rooms—were usually leased to customers rather than sold . Service and all software available were usually supplied by manufacturers without separate charge until 1969. Computer vendors usually provided the source code for installed software to customers. Customers who developed software often made it available to
5376-619: The legal status of software copyright , especially for object code , was not clear until the 1983 appeals court ruling in Apple Computer, Inc. v. Franklin Computer Corp . According to Brewster Kahle the legal characteristic of software changed also due to the U.S. Copyright Act of 1976 . Starting in February 1983 IBM adopted an " object-code -only" model for a growing list of their software and stopped shipping much of
5460-527: The operating system's first graphical screen is displayed, input and output are typically handled through BIOS. A boot menu such as the textual menu of Windows, which allows users to choose an operating system to boot, to boot into the safe mode , or to use the last known good configuration, is displayed through BIOS and receives keyboard input through BIOS. Many modern PCs can still boot and run legacy operating systems such as MS-DOS or DR-DOS that rely heavily on BIOS for their console and disk I/O, providing that
5544-471: The operating system. More recent operating systems do not use the BIOS interrupt calls after startup. Most BIOS implementations are specifically designed to work with a particular computer or motherboard model, by interfacing with various devices especially system chipset . Originally, BIOS firmware was stored in a ROM chip on the PC motherboard. In later computer systems, the BIOS contents are stored on flash memory so it can be rewritten without removing
5628-425: The option ROM scan is completed and all detected ROM modules with valid checksums have been called, the BIOS calls interrupt 19h to start boot processing. Post-boot, programs loaded can also call interrupt 19h to reboot the system, but they must be careful to disable interrupts and other asynchronous hardware processes that may interfere with the BIOS rebooting process, or else the system may hang or crash while it
5712-548: The point of successfully initializing a video display adapter. Options on the IBM PC and XT were set by switches and jumpers on the main board and on expansion cards . Starting around the mid-1990s, it became typical for the BIOS ROM to include a "BIOS configuration utility" (BCU ) or "BIOS setup utility", accessed at system power-up by a particular key sequence. This program allowed the user to set system configuration options, of
5796-712: The public without charge. Closed source means computer programs whose source code is not published except to licensees. It is available to be modified only by the organization that developed it and those licensed to use the software. In 1969, IBM, which had antitrust lawsuits pending against it, led an industry change by starting to charge separately for mainframe software and services, by unbundling hardware and software. Bill Gates ' " Open Letter to Hobbyists " in 1976 decried computer hobbyists' rampant copyright infringement of software, particularly Microsoft's Altair BASIC interpreter, and asserted that their unauthorized use hindered his ability to produce quality software. But
5880-621: The reverse of this, and BIOS ROM code is usually copied ("shadowed") into RAM so it will run faster.) Option ROMs normally reside on adapter cards. However, the original PC, and perhaps also the PC XT, have a spare ROM socket on the motherboard (the "system board" in IBM's terms) into which an option ROM can be inserted, and the four ROMs that contain the BASIC interpreter can also be removed and replaced with custom ROMs which can be option ROMs. The IBM PCjr
5964-403: The same term [REDACTED] This disambiguation page lists articles associated with the title BCU . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=BCU&oldid=1216010577 " Category : Disambiguation pages Hidden categories: Short description
6048-561: The software from becoming unsupported and unavailable abandonware . 3D Realms and id Software are famous for the practice of releasing closed source software into the open source . Some of those kinds are free-of-charge downloads ( freeware ), some are still commercially sold (e.g. Arx Fatalis ). More examples of formerly closed-source software in the List of commercial software with available source code and List of commercial video games with available source code . Proprietary software
6132-484: The software. This is particularly common with certain programming languages . For example, the bytecode for programs written in Java can be easily decompiled to somewhat usable code, and the source code for programs written in scripting languages such as PHP or JavaScript is available at run time . Proprietary software vendors can prohibit the users from sharing the software with others. Another unique license
6216-402: The source code available. Some licenses for proprietary software allow distributing changes to the source code, but only to others licensed for the product, and some of those modifications are eventually picked up by the vendor. Some governments fear that proprietary software may include defects or malicious features which would compromise sensitive information. In 2003 Microsoft established
6300-476: The source code is made available . Governments have also been accused of adding such malware to software themselves. According to documents released by Edward Snowden , the NSA has used covert partnerships with software companies to make commercial encryption software exploitable to eavesdropping, or to insert backdoors . Software vendors sometimes use obfuscated code to impede users who would reverse engineer
6384-606: The source code, even to licensees. In 1983, binary software became copyrightable in the United States as well by the Apple vs. Franklin law decision, before which only source code was copyrightable. Additionally, the growing availability of millions of computers based on the same microprocessor architecture created for the first time an unfragmented and big enough market for binary distributed software. Software distributions considered as proprietary may in fact incorporate
6468-672: The stack set up by BIOS is unknown and its location is likewise variable; although the boot program can investigate the default stack by examining SS:SP, it is easier and shorter to just unconditionally set up a new stack. At boot time, all BIOS services are available, and the memory below address 0x00400 contains the interrupt vector table . BIOS POST has initialized the system timers, interrupt controller(s), DMA controller(s), and other motherboard/chipset hardware as necessary to bring all BIOS services to ready status. DRAM refresh for all system DRAM in conventional memory and extended memory, but not necessarily expanded memory, has been set up and
6552-537: The system has a BIOS, or a CSM-capable UEFI firmware. Intel processors have reprogrammable microcode since the P6 microarchitecture. AMD processors have reprogrammable microcode since the K7 microarchitecture. The BIOS contain patches to the processor microcode that fix errors in the initial processor microcode; microcode is loaded into processor's SRAM so reprogramming is not persistent, thus loading of microcode updates
6636-479: The system is initialized, the first instruction of the BIOS appears at that address. If the system has just been powered up or the reset button was pressed (" cold boot "), the full power-on self-test (POST) is run. If Ctrl+Alt+Delete was pressed (" warm boot "), a special flag value stored in nonvolatile BIOS memory (" CMOS ") tested by the BIOS allows bypass of the lengthy POST and memory detection. The POST identifies, tests and initializes system devices such as
6720-405: The system timer-tick interrupt, which BIOS always uses at least to maintain the time-of-day count and which it initializes during POST, to be active and for the keyboard to work. The keyboard works even if the BIOS keyboard service is not called; keystrokes are received and placed in the 15-character type-ahead buffer maintained by BIOS.) The boot program must set up its own stack, because the size of
6804-461: The type formerly set using DIP switches , through an interactive menu system controlled through the keyboard. In the interim period, IBM-compatible PCs—including the IBM AT —held configuration settings in battery-backed RAM and used a bootable configuration program on floppy disk, not in the ROM, to set the configuration options contained in this memory. The floppy disk was supplied with
6888-780: The user performs a restore using a pre-customised image provided by the OEM. Power users can copy the necessary certificate files from the OEM image, decode the SLP product key, then perform SLP activation manually. Some BIOS implementations allow overclocking , an action in which the CPU is adjusted to a higher clock rate than its manufacturer rating for guaranteed capability. Overclocking may, however, seriously compromise system reliability in insufficiently cooled computers and generally shorten component lifespan. Overclocking, when incorrectly performed, may also cause components to overheat so quickly that they mechanically destroy themselves. Some older operating systems , for example MS-DOS , rely on
6972-754: The year 2000, most BIOSes provide ACPI , SMBIOS , VBE and e820 interfaces for modern operating systems. After operating systems load, the System Management Mode code is still running in SMRAM. Since 2010, BIOS technology is in a transitional process toward UEFI . Proprietary software Proprietary software is a subset of non-free software , a term defined in contrast to free and open-source software ; non-commercial licenses such as CC BY-NC are not deemed proprietary, but are non-free. Proprietary software may either be closed-source software or source-available software . Until
7056-433: Was named "CBIOS" (for "Compatibility BIOS"), whereas the "ABIOS" (for "Advanced BIOS") provided new interfaces specifically suited for multitasking operating systems such as OS/2 . The BIOS of the original IBM PC and XT had no interactive user interface. Error codes or messages were displayed on the screen, or coded series of sounds were generated to signal errors when the power-on self-test (POST) had not proceeded to
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