The role of documentation in implementation (was: Re: Windows keyboard restrictions)

Marcel Schneider charupdate at
Tue Aug 11 13:51:33 CDT 2015

Iʼve got a driver with a five code units ligature on Shift+Ctrl+Alt, and where Word (and Excel) opened. As I was in a hurry and wrote in English, I didnʼt notice that the dead keys were disabled. That was the driver I was writing about when I spun off this thread.

Now Iʼve compiled a driver where the only difference is that two complete lines (the ones with the ellipses) are inverted, at a place that isnʼt sorting sensitive. Word and Excel are blocked. I tried again the driver above: Firefox and Zotero are blocked.

Itʼs very hard for me to write this to the Mailing List, but honestly I must admit that having not enough time, I didnʼt work properly.

All that, and some more, leads me to the conclusion that when Windows was built, there was often not enough time to write up the documentation; or there was a fear that such a documentation could be copied and carried away. So the teams were told not to waste any time upon. These are suppositions, but as everybody at Microsoft mustnʼt disclose any information about how things were done (for the same reason that thereʼs little documentation), weʼre reduced to build our own views, to get at least some working idea.

So now I believe that when Michael Kaplan did his own tests, he found out that thereʼs a problem when he put on Shift+Ctrl+Alt a ligature that exceeded four code units, and that he asked some colleagues but nobody knew anything about, so he remembered the header file he had seen (but that perhaps he couldnʼt find again because it hadnʼt been documented).

Really, when 16 units work on all shift states except one, an official keyboard layout software must equalize the limit at the low level. If a user read that he could put up to 16 on all shift states except on Shift+AltGr, where he could put up to 4, he would get a curious feeling. Itʼs like the Liebig rule: the lowest level determines the overall limit.

But when developing ready-to-use keyboard layouts with the WDK, as Michael Kaplan seems to suggest in the MSKLC glossary, we arenʼt caught to stick with the safe limit and may feel free to place as many units as we find really working. Well, when I place less than five on Shift+Ctrl+Alt, Iʼm not forced to divulge that more wouldnʼt work there. Iʼm not meant to write up the documentation Microsoft didnʼt :-)

Best regards,

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