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A20 Gate

Posted: Wed Jan 05, 2005 12:00 am
by Peter
Hey people,

I'm Dutch so try to answer simple.
My question is about the A20 gate. If you read port 0x64 and test it on bit 1 you will test if the keyboard-controller is ready. But what are you testing if you doing it on bit 2?

Thanks :D

Re: A20 Gate

Posted: Wed Jan 05, 2005 12:00 am
by new_world
If bit 2 isn't clear then the output buffer isn't empty. You must wait till bit 2 is clear, then the command is sent.
For A20 you must wait some time that A20 is *really* enabled.

Re: A20 Gate

Posted: Wed Jan 05, 2005 12:00 am
by Peter
Thanks new_world :-D