geekhack Marketplace > CM Storm

QFR, PS/2 interface and Scroll Lock

(1/2) > >>

ipodah:
Hello, I just received a QFR and plugged it using the PS/2 adaptor to check if everything was ok. I quickly noticed that the led of the SCR LK key wouldn't turn on (the leds of the CAPS LOCK and the F9 keys do work). I downloaded Switch Hitter and, actually, pressing SCR LK doesn't do anything when using the PS/2 interface, the key doesn't send any code.

I then tried to plug the keyboard using the USB interface and tested again. This time, the SCR LK key press is detected according to Switch Hitter and the led does turn on. Good, looks like neither the switch nor the lead are dead.

The question is: is this normal behavior? Did someone observe the same thing with the PS/2 inteface? Should I be worried? Is there something wrong with the PS/2 interface or adaptor? I actually don't really use SCR LK but I'd like to know if the keyboard is just working fine. Thanks.

rowdy:
Did you plug in the keyboard to PS/2 with the computer turned off, then start the computer?

PS/2 interface is not designed to hot plug devices.

ipodah:
No, I did plug the keyboard to PS/2 with the computer on. I was actually surprised it worked for the other keys though (all except scroll lock) and it made me doubt. But I'll try to plug it while the machine is off. Thanks!

Melvang:

--- Quote from: ipodah on Fri, 06 February 2015, 23:18:23 ---No, I did plug the keyboard to PS/2 with the computer on. I was actually surprised it worked for the other keys though (all except scroll lock) and made me doubt. But I'll try to plug it while the machine is off. Thanks!

--- End quote ---

In the future please do not plug PS/2 keyboards in with the PC on.  There is actually a chance it can destroy hardware.  Granted it is a smaller chance now that years ago, but still a real possibility.

ipodah:

--- Quote from: Melvang on Fri, 06 February 2015, 23:35:27 ---In the future please do not plug PS/2 keyboards in with the PC on.  There is actually a chance it can destroy hardware.  Granted it is a smaller chance now that years ago, but still a real possibility.

--- End quote ---

Well, thanks for letting me know, I'll definitely never do that again.

Back to my little "issue", I did try to plug the keyboard using the PS/2 interface while the machine was off and it didn't "solve" the problem, same behavior. But I did find the solution/explanation.

I'm actually using a Dell laptop with a docking station and after doing some research, I discovered that there is an option in the BIOS called "Fn Key Emulation" which allows you to match the <Scroll Lock> key feature of PS-2 keyboard with the <Fn> key feature in an internal keyboard. And this option is enabled by default.

So, by default, on the PS/2 interface, the Scroll Lock key acted as a modifier and no scancode was sent when pressing it (at least that's my understanding), as I observed.

After disabling the option in the BIOS, the Scroll Lock key just acts "normally" on the PS/2 interface, it sends the expected scancode and the led turns on/off. The keyboard and the PS/2 adaptor are working just fine.

Navigation

[0] Message Index

[#] Next page