BlackTop

There is no key for turning the screen off. You can wait for the timeout, or put the whole machine to sleep, and neither covers the situation where the computer should keep working while the display should not be on. BlackTop fills that gap with a hotkey.

Press it and the display actually powers down, receiving no signal rather than showing a black picture. Everything running carries on exactly as it was.

An option locks the session at the same time, so stepping away covers both the screen and the machine in one keystroke.

The situations where this actually matters

Three BlackTop situations come up repeatedly and they are all real.

A long task running overnight, meaning a render, an encode, a backup or a large download, does not need a display. Leaving one lit for eight hours is wasted power and, in a bedroom, wasted sleep.

A machine in a room where somebody else is trying to sleep is the second, and the glow from a monitor at two in the morning is more disruptive than the noise from the fans.

The third is newer and better than the others. Displays using organic panels degrade where a static image sits for long periods, so turning the screen off promptly rather than waiting out a timeout is properly protective on that hardware.

The mouse problem

Here is the practical irritation, and it decides whether BlackTop solves your problem at all.

The display wakes on any input, which includes the smallest movement of the mouse. A sensitive mouse on a desk that gets bumped, a cat, or a slightly uneven surface will wake the screen again within seconds of turning it off.

That is the system behaving as designed rather than a fault in the software, and it is why people sometimes conclude the tool does not work. Moving the mouse out of reach, or lifting it off the desk, is the actual fix.

Locking the session at the same time helps, since a locked machine wakes to a password prompt rather than to your work, which at least means an accidental wake reveals nothing.

What it does not save

Being clear about the BlackTop boundary, because the power argument gets overstated.

The display stops drawing power and the computer does not. The processor, the drives and everything else continue exactly as before, so this is not a power-saving measure for the machine, only for the screen attached to it.

That is the point rather than a shortcoming, since the whole purpose is keeping the machine working. Anybody wanting the machine to stop should use the system’s own sleep instead.

The same thing with a script

For anybody who already automates their desktop, the BlackTop behaviour is a few lines rather than a program.

AutoHotkey can bind the same display power command to any key combination, which suits somebody who already has a script running and would rather add a line than add an application.

The argument for a dedicated tool is that it needs no scripting knowledge and works the moment it is opened, which for a single hotkey is a reasonable trade.

Conclusion

BlackTop exists because of an odd gap in what the system provides. Timeouts and sleep both exist, and a key that turns off only the display does not, which matters more than it sounds for anybody running long tasks or sharing a room.

Expect to deal with the mouse. The display wakes on the faintest input, so the habit that makes this work is moving the mouse aside as you press the key. Do that and it does exactly what it says, in about the smallest program that could possibly do it.