keyboard blocks interrupt 0

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keyboard blocks interrupt 0

Postby jmrams » Wed Oct 01, 2014 3:14 am

I have a system wich requires an interruption every 1 ms (+- 10 us). The question is that if I am using usbkey driver the 0 interrupt could be blocked for 300 us, I have not this trouble if I am only using usb disk drivers. Any idea to solve that?

Thanks
jmrams
 
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Re: keyboard blocks interrupt 0

Postby Bret » Wed Oct 01, 2014 3:48 pm

How long it takes to process a keystroke is dependent on the computer hardware. If the hardware is compatible with typing method 1, it takes a minimal amount of time. But, if the hardware is not compatible and USBKEYB needs to use typing method 3, it can take a long time to process a keystroke (and the "lock" keys -- ShiftLock, CapsLock, ScrollLock -- take even longer). If USBKEYB is installed, you can see what typing method it is using with the /Status option, and you can change the method with the /Method:# option (where # is 1, 2, or 3).

Installing the Microsoft KEYB driver program can sometimes fix a computer so that typing method 1 will work. Note that it needs to be the Microsoft KEYB driver (such as from MS-DOS 6 or 7) -- other KEYB drivers (like those from FreeDOS) are not the same.
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