Scroll Lock - The Secret Key THEY Don't Want You to Press!

Everyone has seen it, most of us have one, but what the heck does the Scroll Lock key do and why is there? What is its purpose? What are its origins? Dave reports in this brief segment from the front seat of the Truthmobile, his 1970 GMC Sierra Grande Custom Camper, a two-owner, all-original big-block 402 with almost every option available.

For information on my book, Secrets of the Autistic Millionaire:

[PKudu]

Finally, a guy sitting in his truck who knows what he's talking about.

[johnadams]

Scroll Lock was essentially a prank key at an office I worked in. For data security, office policy was that you were supposed to lock your computer if you stepped away from it. So if someone was away from their pc and it was unlocked then pressing the scroll lock button was one of the possible consequences. We used excel extensively, and coming back to find your computer behaving totally weirdly when trying to cursor around caught all of us out the first time it happened to us.

[dichebach]

I'm old enough to have: learned to type on a mechanical typewriter, then "re-learned" on an electric, then eventually discovered the marvels of PC word-processing. I think I did at one point actively use the scroll-lock functionality as part of crunching through massive spreadsheet work. But as began to watch this video, I had forgotten that and had a blank as to what Scroll-Lock actually did. Now reminded, I have come full circle twice: a figure eight!

[supermalavox]

As a blind computer user, I enjoy learning everything related to keyboard shortcuts. After all, even though screen reading programs can speak what is under the mouse cursor, we tend to use the keyboard much more. So I surely enjoyed these informations on scroll lock!

[fredashay]

Yes, you are 100% correct at 2:58 as to the purpose of the Scroll Lock key.
Actually, Scroll Lock was on IBM mainframe terminals (3277) long before microcomputers were a thing (even before the Imsai 8080 and the Altair 8080).
I suspect they ended up standard on modern PCs because IBM put the Scroll Lock key on their original IBM PC keyboard to be compatible with mainframes for some applications and it just became a legacy feature.

[Elder-Sage]

In the IBM PC world, during the early PC/XT era, all the lock keys worked solely from the keyboard. The keyboard interface did not support two way communications. All information flowed from the keyboard to the computer. The state of the locks was entirely in the domain of the keyboard itself. Most of them did this through on board logic controllers, however there are the odd keyboards that used actual locking keys that stayed in a depressed state upon tapping. This all changed in 1984 with the introduction of the IBM PC/AT. A new protocol was introduced via the addition of a Intel 8042 controller. This provided two way communications allow the PC to change not only the lock state of the keyboard but also allowed independent control of the indicator LEDs. The i8042 is long gone in modern PCs, but is still emulated in current PS/2 and USB interfaces. All this being said the history of all the lock keys goes far beyond the IBM's original PC over 40 years ago.

[WardenWolf]

I use Scroll Lock and Pause / Break as mute buttons in voice chat apps. I'm glad they exist because they're perfectly suited to this purpose; otherwise unused and located away from keys you might actually want to press. And Scroll Lock provides a nice light to tell me when I'm muted.

The reason they don't set caps lock on or off with password fields is because the caps lock is a low level system function and doing so would allow applications dangerous levels of access. You can normally turn caps lock on and off unless the system is completely frozen.

[WatchesTrainsAndRockets]

Before there was Windows, the scroll lock was used to keep the text on the screen from scrolling. It allowed the user to freeze the output before it scrolled off the top of the screen. Yes, you can pipe it into MORE, but that is not always an option.

[MarcTompkins]

I did know about the standard/approved function of ScrollLock, but I'm surprised you didn't mention its (slightly) more modern use: it was the default switch key for nearly all hardware KVM switches from the 90s through the 10s or so, and - though I haven't needed a KVM switch in quite a while - I bet it's still used that way on current models. Drove me nuts when keyboards started popping up without a Scroll Lock key!
(For those unfamiliar: a KVM switch allows you to operate multiple computers with a single Keyboard, Video monitor, and Mouse; you either press a button on the KVM, or more commonly press Scroll Lock on the keyboard, to switch between them. Very useful in server rooms/data centers or on the workbench of a PC builder/repair shop.)

[SylviusTheMad]

As someone who relies heavily on the Pause|Break key, I am very glad to know what Scroll Lock does.

However, I vaguely recall that Scroll Lock would prevent the document from scrolling in WordPerfect 5.1 for DOS. Unfortunately, I can no longer verify this.

[StevenOBrien]

Thank you Dave for risking your life to bring this information to us.

[MickPsyphon]

The Scroll Lock key actually predates personal computers. While I don't know exactly when it was first implemented, I can confirm that it was present on some dumb terminals connected to mainframes, which we used to develop programs.

When reading pages and pages of programming code, or system dumps, the scroll lock would make it easier to ensure we didn't miss anything; and even made it possible to take breaks and pick up where we left off.

It was carried over onto PC keyboards to allow virtual terminals to do the same thing as a dumb terminal.

Everything else is pretty much what he said

[bagabooo]

These type of “secret history of… “ are my favourite episodes.

10 minutes is perfect length for a quick fyi type video.

20 minutes also works for more in-depth topics, just more difficult to put it on as soon as you uploaded it.

Thank you Dave. Keep the interesting stories coming ✊

[doublebrewski]

At work, when someone accidentally hits Scroll Lock, it basically locks our software from typing or doing anything. Hitting it by accident became such a common annoyance that I eventually took my pocket knife and popped off each Scroll Lock key off of every keyboard in the building.

[StephanieDaugherty]

Also worth mentioning, just about every KVM switch I've ever seen uses two quick presses of Scroll Lock to send commands to the KVM, likely because of how ubiquitous yet seldom used the Scroll Lock key is.

[borgdylan]

The scroll lock led is used on gnome shell to remind the user when setting an alternate input language. The led stays on until the normal input language is reactivated.

[morzee]

I love hearing the human story behind things we’ve all come across in the world. Thanks for your content Dave!

[Icedmindblow]

Your channel popped up in my recommendations and I can't stop watching. I started using "PCs" when my parents bought a C64, and my very first x86 PC I ever owned was a Win95 with Pentium 120MHz and 8MB RAM... and a HUGE 1, 2GB hard drive 😂 one thing I figured out very early is, that you never stop learning new (and even old) things in the IT world. The scroll lock function and the F7 option in browsers was something I never knew until I watched this clip. Which is kinda embarassing, since I work as service desk engineer for an IT firm. Then again, most of our customers and users are office workers, they're already happy if the rig boots up properly and the VM doesn't crash every 2 minutes 😄 Thanks for sharing your expertise with us, I will definitely make good use of these tricks and tips and "did you know" parts at work.

[Pooua]

I haven't used the Scroll Lock key since I gave up programming in DOS. I used it only to keep my screen echo from scrolling off the screen too fast, anyway. My current keyboard doesn't even have a scroll lock key, replacing that position on my keyboard with an LED key that changes the color of my keyboard backlight.

Beautiful truck. I'm not much of an auto guy, but I appreciate the craftsmanship.

[IanSlothieRolfe]

Looking forward to the deep dive into the "Sys Rq" key next :)