Messages in this thread | | | Date | Mon, 28 Jul 2003 17:51:18 +0200 | From | Andries Brouwer <> | Subject | Re: i8042 problem |
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On Mon, Jul 28, 2003 at 05:43:51PM +0200, Maciej W. Rozycki wrote: > On Mon, 28 Jul 2003, Andries Brouwer wrote: > > > > Well, are timeouts needed at all? > > > > Yes. We send a command to the keyboard. It may react, or it may not. > > But we need not wait for that actively. If we are unsure about a result > of a command, then we may send a command in question followed with an echo > request. This assures an IRQ will finally arrive and if no command > response arrives before an echo response, then the keyboard ignored the > command. I used this approach many years ago to differ between PS/2 > keyboards (which respond with 0xfa,0xab,0x83 to a request for ID) and > genuine PC/AT ones (which respond with lone 0xfa). It worked.
And what did you do for XT? :-)
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