Key pressed during KeyWarrior Startup?

[carstenk]

What happens when a key is pressed and held down during the whole power-up/USB enum, Windows-Boot, etc. process? Is it simply ignored until first released, or will it 'block' something?


- Carsten

[Guido Körber]

The key will be reported as pressed. When using the PS/2 interface that can mean the key is send in typematic mode. If that blocks anything depends on the host, the KeyWarrior does not have any problems with this.

[carstenk]

Okay, naturally I would have to take care that we don't use keys that systematically interfere with the boot process, e.g. F8 etc. ;-)

- Carsten

[carstenk]

Maybe the clean solution for this is: The KeyWarrior LED outputs can be activated by software (There are various tools for this). As such, they can be used as three bit output port. I will use Scroll-Lock as a control signal for a transistor/relais that activates the switch voltage for the optocouplers. That way the KeyWarrior can be active and enumerated upon system start, while Keys will only be 'pressed' after activation of Scroll-Lock through my application/autostart/timescheduler.

- Carsten

[Guido Körber]

On Windows the LEDs are always set for all keyboards. Lock states can also be set by the BIOS.

[carstenk]

That's no problem with this application, as my 'special' keyboard will be the only one being used on that machine. A normal Keyboard will only be used for maintenance every once in a while. Even then the Scrollkey or LED shouldn't be a problem.

- Carsten

[carstenk]

I was now able to actually test this: I programmed a typing macro with just 'F8', held the matrix contacts connected while powering up the computer - and slightly unexpected, Windows offered me the boot/safe boot menu. In fact I thought that when the system powers up, the first few keystrokes would simply be flushed, and the typing macro 'F8' would be a single keystroke anyway.
Wrong - a closed matrix key during power up will be reported and acted on properly, at least on systems with legacy USB support.

No problem though, I don't need F8 in my application and if the keys I do need cause trouble, I have the mentioned hardware solution which enables the optocoupler switch current only after startup.

- Carsten