Talk:System request

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Regarding footnote #3:

Could find nothing on the internet about Sandy Meade, who he/she is, or what their function was.

How does the author know enough to make the claim that person invented the SysRq key? Facts needed. —Preceding unsigned comment added by Ssybesma (talk • contribs) 02:05, 30 September 2009 (UTC)Reply

I've always wondered about this key. Does anyone know what it was originally used for? --Stephen Gilbert

It was used by Microsoft OS/2 1.0 to initiate task switching. IBM added the key to the PC AT, the first PC to use the Intel 80286 chip, which made pre-emptive multitasking practical. IBM felt that a hardware-level interrupt that could be initiated by the user would be handy. Oddly, when IBM later took over OS/2, they didn't make much use of the key. --LDC

Deleted "e.g., the linux kernel can be compiled with "Magic System Request Key support" (without using the BIOS, most likely)" since I'm pretty sure Linux doesn't use the BIOS for this, and any other key could have been chosen instead of SysRq. Put the comment in a separate paragraph, without any implication of it having anything to do with the BIOS. -- SJK

When MS-DOS was the dominant operating system (version 6, certainly), pressing SysRq would output subsequent screen output to my printer. It was useful to print a directory listing - turn on SysRq, type dir, then turn off SysRq. Print Screen, on the other hand, would print whatever was visible on the screen at the time the key was pressed. —Preceding unsigned comment added by Jamietshaw (talk • contribs) 21:31, 18 June 2010 (UTC)Reply

This key was originally put onto the PC keyboard, as it was present on IBM3270 keyboards. IBM had great hopes that the PC would be used as an intelligent terminal for their mainframes.

One of the great mysteries of life solved at last. Why didn't I think to look here before? — Trilobite (Talk) 07:16, 7 Feb 2005 (UTC)

If the magic sysrq key is part of the Linux Kernel, it should work with all Linux-based systems, not just GNU/LINUX (The most common Linux variant) right? 42istheanswer 22:13, 29 October 2005 (UTC)Reply

The most common variant? If there is a linux that isn't GNU/Linux, show me it. That said, since we're discussing only the kernel here, writing Linux instead of GNU/Linux is indeed correct.

In Windows, tou cna coyp the active window (instead fo the whole screen to the clipboard by pressing Alt+Pritn Screen. This would technically be the SysRq command, wouldn't it?

Good question. I also wondered about this. Since my notebook has separate keys for PrintScreen (Fn+Insert) and SysRq (Fn+Delete), i could test that. It happens that i only get the image of the current window using Alt+PrintScreen (i.e., Fn+Alt+Insert), not by pressing SysRq (Fn+Delete, which does nothing on my Windows). Now i wonder what's the difference between Alt+PrintScreen and SysRq. Maybe the the text on the key of my keyboard is wrong? Or SysRq is not the same as Alt+PrintScreen, after all (at least on Windows)? Oh dear, another mystery about the SysRq key! --qnac

Well on my keyboard Pause/Break is notated the same as PrintScreen/SysRq... traditionally break was control+pause, so maybe ctrl+printscreen invokes the SysRq function. 130.101.20.142 16:35, 11 October 2006 (UTC)Reply

This is complicated. SysRq really only exists as a separate function under BIOS/DOS, where it has a special software interrupt assigned to it. Windows 95 and later, and all versions of Windows NT, don't use DOS/BIOS for keyboard I/O. They read keyboard scan codes, which correspond to physical keys on the keyboard. So whatever labels might happen to be on the keyboard don't really matter to Windows. What Microsoft is after there is "Print Screen", not "System Request", so I'd say they key is acting as "Print Screen" in that usage. —DragonHawk (talk|hist) 06:26, 8 January 2008 (UTC)Reply

Just adding to this discussion out of interest. On my netbook (Lenovo S10), when I press SysRq (Fn+Ins), it has the same effect as just PrintScreen ie It takes a screenshot of the entire screen. Looks like different units implement this differently... — 0612 (TALK); Posted: 11:24, 16 September 2009 (UTC)Reply

Are you sure that the kernel debugger is attached by IEEE 1394 (Firewire) or IEEE 1284 (parallel)? I don't know, but in Win NT wasn't support for Firewire. —Preceding unsigned comment added by 89.6.17.218 (talk) 15:22, 10 September 2007 (UTC)Reply

In more recent versions of NT, the debugger can be attached via serial cable, FireWire, and some other things, as noted in the MSKB article I just added. Irrelevant now, as I've trimmed back that stuff, since it was superfluous to the article topic. —DragonHawk (talk|hist) 06:22, 8 January 2008 (UTC)Reply

I think the comment about sysreq tsr for killing current process in DOS is untrue. I couldn't find anything online about it. Cany anyone cite this? I'd love to use it! — Preceding unsigned comment added by 71.254.115.213 (talk) 00:11, 5 October 2011 (UTC)Reply