Editing Break key (section)

==Modern keyboards==
On many modern [[personal computer|PCs]], {{keypress|Pause}} interrupts screen output by [[BIOS]] until another key is pressed. This is effective during [[booting|boot]] in [[text mode]] and in a [[DOS]] box in [[Microsoft Windows|Windows]] safe mode with 50 lines. On early keyboards without a {{keypress|Pause}} key (before the introduction of 101/102-key keyboards) the Pause function was assigned to {{keypress|Ctrl|NumLock}}, and the Break function to {{keypress|Ctrl|ScrLock}}; these key-combinations still work with most programs, even on modern PCs with modern keyboards. Pressing the dedicated {{keypress|Pause}} key on 101/102-key keyboards sends the same [[scancode]]s as pressing {{keypress|Ctrl}}, then {{keypress|NumLock}}, then releasing them in the reverse order would do; additionally, an E1<sub>hex</sub> prefix is sent, which enables 101/102-key-aware software to discern the two situations, while older software usually just ignores the prefix. The {{keypress|Pause}} key is different from all other keys in that it sends no scancodes at all on release in PS/2 modes 1 or 2, so it is impossible to determine whether this key is being held down with older devices. Also, it's not "typematic", that is, unlike the other keys, it doesn't send repeat scancodes while being held.  In PS/2 mode 3 or USB HID mode, there is a release scancode, so it is possible to determine whether this key is being held down on modern computers.<ref>{{cite book |url=https://archive.org/details/ps-2-hardware-interface-technical-reference-ocr/PS2HardwareInterfaceTechnicalReference-OCR/page/n582/ |title=PS/2 Hardware Interface Technical Reference |date=October 1990 |publisher=IBM |page=19 |chapter=Keyboard 101- and 102-Key |quote=Except for the Pause key, all keys are make/break... Also, except for the Pause key, all keys are typematic |archive-url=https://ghostarchive.org/archive/20221009/http://www.mcamafia.de/pdf/ibm_hitrc11.pdf |archive-date=2022-10-09 |url-status=live}}</ref>

On modern keyboards, the {{keypress|Break}} key is usually labeled ''Pause'' with ''Break'' below, sometimes separated by a line: {{keypress|{{Sfrac|Pause|Break}}}}, or ''Pause'' on the top of the keycap and ''Break'' on the front, or only ''Pause'' without ''Break'' at all. Keyboards with [[ISO/IEC 9995]]-7 markings including Canadian [[CSA keyboard]] use <big>'''⎊'''</big> symbol for ''Break'' and <big>'''⎉'''</big> for ''Pause''.<ref name=":2" /> In most Windows environments, the key combination {{keypress|Win|Pause}} brings up the system properties.