In computing, BIOS is firmware used to provide runtime services for operating systems and programs and to perform hardware initialization during the booting process. The BIOS firmware comes pre-installed on an IBM PC or IBM PC compatible's system board and exists in some UEFI-based systems to maintain compatibility with operating systems that do not support UEFI native operation. The name originates from the Basic Input/Output System used in the CP/M operating system in 1975. The BIOS originally proprietary to the IBM PC has been reverse engineered by some companies looking to create compatible systems. The interface of that original system serves as a de facto standard.
In digital computers, an interrupt is a request for the processor to interrupt currently executing code, so that the event can be processed in a timely manner. If the request is accepted, the processor will suspend its current activities, save its state, and execute a function called an interrupt handler to deal with the event. This interruption is often temporary, allowing the software to resume normal activities after the interrupt handler finishes, although the interrupt could instead indicate a fatal error.
In computing, booting is the process of starting a computer as initiated via hardware such as a button or by a software command. After it is switched on, a computer's central processing unit (CPU) has no software in its main memory, so some process must load software into memory before it can be executed. This may be done by hardware or firmware in the CPU, or by a separate processor in the computer system.
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 terminals, including graphical interfaces. A terminal emulator inside a graphical user interface is often called a terminal window.
In computing, a crash, or system crash, occurs when a computer program such as a software application or an operating system stops functioning properly and exits. On some operating systems or individual applications, a crash reporting service will report the crash and any details relating to it, usually to the developer(s) of the application. If the program is a critical part of the operating system, the entire system may crash or hang, often resulting in a kernel panic or fatal system error.
A touchpad or trackpad is a type of pointing device. Its largest component is a tactile sensor: an electronic device with a flat surface, that detects the motion and position of a user's fingers, and translates them to a position on a screen, to control a pointer in a graphical user interface. Touchpads are common on laptop computers, contrasted with desktop computers, where mice are more prevalent. Trackpads are sometimes used on desktops, where desk space is scarce. Because trackpads can be made small, they can be found on personal digital assistants (PDAs) and some portable media players. Wireless touchpads are also available, as detached accessories.
A boot disk is a removable digital data storage medium from which a computer can load and run (boot) an operating system or utility program. The computer must have a built-in program which will load and execute a program from a boot disk meeting certain standards.
David J. Bradley is one of the twelve engineers who worked on the original IBM PC, developing the computer's ROM BIOS code. Bradley is credited for implementing the "Control-Alt-Delete" (Ctrl-Alt-Del) key combination that was used to reboot the computer. Bradley joined IBM in 1975 after earning his doctorate in electrical engineering from Purdue University with a dissertation on computer architectures.
A watchdog timer, sometimes called a computer operating properly timer, is an electronic or software timer that is used to detect and recover from computer malfunctions. Watchdog timers are widely used in computers to facilitate automatic correction of temporary hardware faults, and to prevent errant or malevolent software from disrupting system operation.
In computing, a non-maskable interrupt (NMI) is a hardware interrupt that standard interrupt-masking techniques in the system cannot ignore. It typically occurs to signal attention for non-recoverable hardware errors. Some NMIs may be masked, but only by using proprietary methods specific to the particular NMI. With regard to SPARC, the non-maskable interrupt (NMI), despite having the highest priority among interrupts, can be prevented from occurring through the use of an interrupt mask.
The magic SysRq key is a key combination understood by the Linux kernel, which allows the user to perform various low-level commands regardless of the system's state. It is often used to recover from freezes, or to reboot a computer without corrupting the filesystem. Its effect is similar to the computer's hardware reset button but with many more options and much more control.
The booting process of Windows NT is the process run to start Windows NT. The process has been changed between releases, with the biggest changes being made with Windows Vista. In versions before Vista, the booting process begins when the BIOS loads the Windows NT bootloader, NTLDR. Starting with Vista, the booting process begins with either the BIOS or UEFI load the Windows Boot Manager, which replaces NTLDR as the bootloader. Next, the bootloader starts the kernel, which starts the session manager, which begins the login process. Once the user is logged in, File Explorer, the graphical user interface used by Windows NT, is started.
The terms Recovery disc, Rescue Disk/Disc and Emergency Disk all refer to a capability to boot from an external device, possibly a thumb drive, that includes a self-running operating system: the ability to be a boot disk/Disc that runs independent of an internal hard drive that may be failing, or for some other reason is not the operating system to be run.
In computing, error recovery control (ERC) is a feature of hard disks which allow a system administrator to configure the amount of time a drive's firmware is allowed to spend recovering from a read or write error. Limiting the recovery time allows for improved error handling in hardware or software RAID environments. In some cases, there is a conflict as to whether error handling should be undertaken by the hard drive or by the RAID implementation, which leads to drives being marked as unusable and significant performance degradation, when this could otherwise have been avoided.
A factory reset, also known as hard reset or master reset, is a software restore of an electronic device to its original system state by erasing all data, settings, and applications that were previously stored on the device. This is often done to fix an issue with a device, but it could also be done to restore the device to its original settings.
In computing, a hang or freeze occurs when either a process or system ceases to respond to inputs. A typical example is when computer's graphical user interface no longer responds to the user typing on the keyboard or moving the mouse. The term covers a wide range of behaviors in both clients and servers, and is not limited to graphical user interface issues.
In computing, rebooting is the process by which a running computer system is restarted, either intentionally or unintentionally. Reboots can be either a cold reboot in which the power to the system is physically turned off and back on again ; or a warm reboot in which the system restarts while still powered up. The term restart is used to refer to a reboot when the operating system closes all programs and finalizes all pending input and output operations before initiating a soft reboot.
Control-Alt-Delete is a computer keyboard command on IBM PC compatible computers, invoked by pressing the Delete key while holding the Control and Alt keys: Ctrl+Alt+Delete. The function of the key combination differs depending on the context but it generally interrupts or facilitates interrupting a function. For instance, in pre-boot environment or in MS-DOS, Windows 3.0 and earlier versions of Windows or OS/2, the key combination reboots the computer. Starting with Windows 95, the key combination invokes a task manager or security related component that facilitates ending a Windows session or killing a frozen application.
A hardware reset or hard reset of a computer system is a hardware operation that re-initializes the core hardware components of the system, thus ending all current software operations in the system. This is typically, but not always, followed by booting of the system into firmware that re-initializes the rest of the system, and restarts the operating system.
MicroPython is a software implementation of a programming language largely compatible with Python 3, written in C, that is optimized to run on a microcontroller.
