Jump to content
Corsair Community

To Corsair: A word about the "stuck key" problem, and the Microsoft USB driver


Recommended Posts

As many people well know, there have been issues with "stuck" keys in some of the Corsair keyboards.


Even though I haven't replicated this type of bug with the Microsoft sidewinder X4/X6 (which also allow 20 simultaneous keypresses), there IS a bug which actually prevents more than 11 simultaneous keys from working correctly, and this may or may not be related in some way to the stuck key issue with the K60/90. It's still worth the Corsair engineers at least investigating just to make sure...even though the K60/K90 problem has nothing to do with trying to bypass 11 inputs...


Brief history:

Awhile ago, I had purchased an I-Pac2 FS32 device, for hooking up arcade controllers to a PC. This device changes the arcade button inputs into keyboard inputs and bypasses the 4-6 key USB limit for simultaneous keypresses. It technically is supposed to do 24, however I found some problems whenever I reached 11+ simultaneous inputs, in some Super Street Fighter 2 Turbo (emulator)/keyboard (Ghostkey in windows XP) test programs.


Basically strange things started happening once you reached 11 simultaneous keys.


Either the last key would be dropped completely and the previous key would start repeating forever (as long as the first 10 were still held down) or the last 2 keys would activate at once, and so on.


Andy Warne told me that this seemed to be a bug in the Microsoft USB keyboard driver, so he did something (a packet size change) to increase the limit, which SHOULD have increased it to 24 correctly).


However, when testing the new firmware, I found out that the limit had gone only from 11, to 13!


After this, Andy said that this is definitely another issue with the Microsoft keyboard driver, and that in order to increase the # of keystrokes simultaneously, the packet size must be increased exponentially for each extra key needed. He then sent a firmware that allowed either 18 or 19 perfect simultaneous inputs, before the bug reoccured. We decided that this was enough, since no one would ever press this many inputs at once, even on a 2 player game with two controllers hooked ot the I-pac.


Why is this important?


Well, when I bought my Sidewinder X4 eons ago, I noticed that it is advertised as allowing 20 simultaneous inputs at once on the keyboard, but I tested it, and sure enough, anything over 11 bugs out the exact same way as on the I-pac, before the firmware workarounds to allow up to 19 properly.


This packet size thing (although I don't know WHAT packet Andy was referring to, but it was related to something being passed to the microsoft USB driver) MIGHT have something or may help in some relation to the Corsair stuck key problem, even though people aren't getting repeated keys by coming anywhere close to the limits mentioned above (1 or 2 keys can be enough). I hope this information helps someone, somewhere, or might at least help to a solution for the problem with K60/K90 (and hopefully won't affect the K95, either).

Link to comment
Share on other sites


This topic is now archived and is closed to further replies.

  • Create New...