svn commit: r294011 - head/share/man/man4

[Bruce Evans]

On Thu, 14 Jan 2016, Slawa Olhovchenkov wrote:

> On Fri, Jan 15, 2016 at 06:27:05AM +1100, Bruce Evans wrote:
>> The BREAK_TO_DEBUGGER option used to mean: enter (not break into) the
>> debugger using a serial line break.  This is a good method, except it
>> ...
>>
>> This option was broken to mean: the default for the sysctl that controls
>> "breaking into" the debugger using either a serial line break or the console
>> key for "breaking into" the debugger.  For almost perfection confusion,
>> this key is normally the "Ctrl-Print Screen" key on PC keyboards and
>> there is a "Break" key nearby.  Ctrl-Alt-Esc also works.  syscons(4)
>
> On may keyboard "Break" subscribe to "Pause", to "Print Screen"
> subscribe "SysReq".

This is similar but not quite the same on all 6 of my (US) keyboards
(except it is the same on 2 identical models).  SysReq seems to be
going away and is only on my 2 20+ year old keyboards.  PrintScreen is
is even more useless/unsupported for its original operation.  But
my worst (and most expensive) keyboard axed ScrollLock before
PrintScreen.  I use ScrollLock a lot under FreeBSD but never noticed
it doing anything elsewhere.

Bruce