Hey I'm Dave, welcome to the cab of my GMC pickup truck.
Now the fact that I'm coming to you live from the cab of a pickup truck means twoe things:
first, it means that the information I'm about to relay to you is critically important, absolutely
true, and so secret that I had to sit in the cab of this truck to even talk about it.
And second, I'm probably in this truck to imply that I might need to make a quick getaway
if I'm caught giving away the information "they" don't want you to know.
And that truth is that the world is divided into two camps.
The people who know what Scroll Lock does and the people who are too afraid to push
the buttons that they don't understand.
The sheeple, if you will.
The people that click OK on the Apple iTunes license agreement without even scrolling a
little bit.
Because that is the legal standard you know: did you scroll a little?
Well, then....
You're a diligent citizen.
I bet you're the kind of person that wants to know what Scroll Lock is for.
Find out now, in Dave's Garage.
[Intro] Now if you count yourself amongst the millions
of people who don't know what the Scroll Lock key is all about, don't feel too bad about
it.
In fact, back when PC Magazine interviewed and asked an executive of KeyTronic, then
a leading keyboard manufacturer, what the Scroll Lock even key did, he replied "I don't
know, but we put it on ours too!"
Like some people's little toenail - not mine, perfect feet, thanks - but like some people's
little toenail, we start to lose superfluous things as we evolve, and some modern keyboards
do in fact lack Scroll Lock.
I'll tell you how to click it if your keyboard doesn't have one so you can join the fun later,
because it still does serve a purpose, and even major applications like Office still
make use of it, even though it's a essentially a vestigial leftover from the days of the
original IBM PC.
On a PC keyboard, the Scroll Lock is actually a toggle key, just like the Num Lock and the
Caps Lock keys are.
An,d just like those lock keys, because they have a state, on or off, it is usually accompanied
by an LED indicator intended to show its state.
But what does that state even mean in the case of Scroll Lock?
Well, it can vary depending on the application.
Because unlike Num Lock or Caps Lock, it does not modify future keypresses.
Rather, it's up to the operating system or application to check the state of the key
and modify its behavior accordingly.
It means whatever the application thinks it means, really.
To quote the manual for the original IBM PC, page 5-20: "This key is interpreted by appropriate
application programs as indicating that the use of the cursor-control keys should cause
windowing over the text rather than cursor movement.
Pressing the Scroll Lock key a second time reverses the action.
The keyboard routine simply records the current shift state of the Scroll Lock key.
It is the responsibility of the system or application program to perform the function."
On that original IBM PC, then, the intent was that Scroll Lock would change how the
cursor keys operated.
If Scroll Lock was on, the arrow keys would not move the cursor - rather, they would move
the contents of the window underneath it.
You can still see this behavior in Excel today.
Let's bring up a blank sheet.
I'll type Dave into a random cell, and then using the cursor keys, as you can see, I can
move the cursor box around at will.
If I press up, the cursor moves up.
Left moves it left, and so on.
Exactly what you're used to and precisely what you've come to expect.
If you press and activate Scroll Lock, however, now something different happens: as I use
the cursor keys, the entire sheet scrolls around.
Instead of the cursor moving, the contents move as though the window itself is sliding
around the page.
There's still lots of application defined behavior to think about though, like what
happens to the cursor?
In the Excel implementation, the cursor stays where you put it relative to the spreadsheet,
not the screen.
In other words, it stays on the original cell and moves around with the content.
So you can't play a game of tail-gunner with a Spreadsheet, using the cursor as a reticle.
But it also means that the cursor can go offscreen, which is something that's not allowed when
Scroll Lock is in the other state, where the cursor is mobile.
So, if a mobile cursor must always be on the screen, but a locked cursor can be pushed
offscreen, what happens if you push the cursor offscreen and then hit the Scroll Lock key
to flip modes?
Join me next time to find out... no I'm kidding, I wouldn't do you like that.
I tested the scenario for you.
If you push the cursor offscreen, then toggle scroll lock back off, nothing happens.
You're now in regular mobile cursor mode, but the cursor is offscreen, an odd state.
But as soon as you do anything with that cursor, whether it's to move it or even just activate
it via the formula bar, Excel will immediately scroll it back into view.
That got me to thinking - maybe lots of applications support scroll lock and I've just overlooked
it as merely an Excel oddity for too long.
After all, did you know you can turn on what's called Caret mode in most web brows ers by
pressing F7?
That'll give you a cursor that you can use to navigate around a web page.
The page only scrolls when you hit the screen edge with your cursor.
But hit F7 again and now the entire screen contents scrolls around instead.
Now wait a minute... that's almost exactly what Scroll Lock is supposed to do for you.
There's literally an underused key on most every keyboard in the world dedicated to that
very purpose, yet they chose F7 instead?
And not only that, Scroll Lock seems to have no effect in the browser.
They least they could have done was have it map to the current state of caret browsing.
But, being a user interface guy by trade, here's what I bet happened: they tried it.
And then some 50% of those people who had never, ever even thought about the Scroll
Lock key, let alone cared which state it was in, were suddenly affected by the cursor doing
the exact opposite of what they hoped and/or expected it would.
And so that became a big usability problem, and someone decided that it was safer to use
an entirely different key that didn't have an existing hardware state or indicator light.
And that way they could set their default behavior to be whatever they wanted it to
be, and at least it would be consistent.
I'm not sure that's the best solution, but it's not my department anymore!
Forgetting that for a moment, I looked up some of the keyboard documentation, and I
did notice that under Windows NT and later you can use the keybd_event() API to toggle
the state of the NUM LOCK, CAPS LOCK, and SCROLL LOCK keys.
It should even set the indicator light appropriately, so they could have prompted the first time
the user launched the browser with it turned on.
Sort of like you're warned about caps lock being on if you enter your password wrong
because of it.
One thing I wonder is whether any keyboards have a physical toggle for any of these keys.
I notice that when you get to a password field they don't set Caps Lock to default off, and
perhaps that's because they can't, if there are keyboards with a two-state caps lock key.
If you have or authoritatively know of a keyboard that did have locking caps lock, num lock,
or scroll lock keys, such that the PC wouldn't be able to change their state programmatically,
let me know in the comments!
Under Linux, Scroll Lock is supposed to freeze console output if pressed during output, but
I didn't have any luck with that working in a WSL Terminal running Ubuntu.
I tried Ctrl-S and Ctrl-Q which should do the same thing, and they worked fine, so it
could be an oddity of the Windows Terminal.
As I mentioned earlier, some keyboards are abandoning it, particularly space-saving units,
so here's a tip: If for some reason you need to use the scroll lock key and don't have
one, you can simply bring up the Windows onscreen keyboard.
The problem is that there seem to be two completely different onscreen keyboards, and both are
wrapped up in accessibility somehow.
What confused me is that if you enable the onscreen keyboard in the notification area,
it lacks the scroll lock.
There's also an onscreen keyboard application on Windows 11 that includes the Scroll Lock
key, and that's how you'll gain access to it if needed.
That one you launch from the Start menu rather than from the notification area.
I find the fastest way to launch it is to press the windows key followed osk, as in
on screen keyboard.
If you find this kind of random Windows story interesting, be sure to subscribe to the channel
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And check out the playlist I'll put in a popup card right now for episodes on everything
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before you go today.
In the meantime and in between time, I hope to see you next time, right here in Dave's
Garage.