To my great surprise, Linux does not support NKRO (N-key roll-over) keyboards connected by USB, and evidently some USB-PS2 adapters (which are no use to us laptop people anyway).
Definitely one for the Linux device driver bucket list. Regards Zenaan --- Firstly, we in the "Linux" community can and do have significant influence over the long term, e.g. re terminology. So on a point of terminology, this might be particularly interesting: https://geekhack.org/index.php?topic=10063.0 "...There's two different families of terminology, and neither is useful in today's keyboard world ...This is a non-artifacting open matrix. ...A non-blocking matrix keyboard can register any number of keystrokes with no blocking or artifacting. However, it may not send all of them to the computer. If it's PS/2, then all keys can be sent at once and it's called NKRO. If it's USB, then traditionally it's limited to 6 keys and 4 modifiers (ctrl, shift, etc.). But some companies have found a way around that, allowing 7 or 11 or 17 or 24 keys to be registered over USB. Using my terminology, you won't have to bother differentiating between the different levels of KRO. It's just blocking, or open (or non-blocking, I guess). Simple. And all the ghosting nonsense? Forget it. Really. It's a word with two meanings, and it's been giving TwoCables seizures since day one, so it's best left in the dust bin of stupid terminology for now. " --- http://ubuntuforums.org/showthread.php?t=2056161&page=2 "Just got an email from the manuafacturer: Sorry for missing your message earlier. Unfortunately, the KB528U Clicker Mechanical Keyboard does not work in Linux. The reason being is the NKRO chipset is not compatible with Linux. The NKRO chipset is responsible for the anti-ghosting gaming features found on this keyboard. " --- http://w3facility.org/question/anti-ghosting-nkro-over-usb-keyboard/ "I’ve recently bought a new keyboard and was surprised to find that it didn’t work in Linux. This keyboard does strange things to handle multiple key presses (ant-ghosting) over a USB interface. While I can disable this behaviour by pressing ctrl+alt+shift+N, this is bit annoying. I’ve written up a lot more detail here. I’ve since procured a USB to PS2 adapter – which doesn’t work at all (in BIOS or in Linux). I suspect it may be faulty but don’t want to spend time and effort (possibly money) trying to get a hacked solution to work. ... " --- http://symcbean.blogspot.co.uk/2013/05/keyboard-still-not-detected-press-f1-to.html --- http://www.reddit.com/r/linux/comments/1ldid1/nkey_rollover_and_linux_compatibility/ --- The keyboard I just ordered, and am now doubtful whether it will even work for me on Linux, which is surprising to say the least: https://www.trulyergonomic.com/store/products https://www.trulyergonomic.com/store/answers-to-frequently-asked-questions-faq--truly-ergonomic-mechanical-keyboard#NKRO "Is it compatible with USB HID and PS2 (PS/2)? The Truly Ergonomic keyboard is only compatible with USB. USB HID device version 3.0, 2.0, or 1.1 - Type A connector. Using a passive USB‑PS2 adapter, and/or a PS2 compatible KVM switch, does not work with a true USB device like ours. The Truly Ergonomic keyboard is compatible with true USB KVM switches. The main reason we decided on USB over PS2 compatibility is because PS2 is an older technology being replaced by USB; where most computers no longer have a PS2 connector. As well, we had two options; one was to have a non‑reprogrammable keyboard compatible with USB and PS2, the second and better option is to have a reprogrammable keyboard compatible with USB. Compared to having the capability of connecting via older PS2, we visualized that is much better being reprogrammable. " --- Couple more links - NKRO driver for Atmel AVR: https://github.com/tmk/tmk_keyboard/blob/master/README.md https://github.com/tmk/tmk_keyboard/wiki/FAQ -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
