Lyndel,

now you have cracked me up in two different fora.

Thanks!

Ernie

PS I think I will simply call it THAT laptop from now on, as in "I am writing this on THAT laptop."

900A generates the signals that those of us reverse engineering the signal structures have been calling "NEC1". 900B generates the signals we have been calling "NEC2".

I have no idea what NEC calls the distinction between what we call "NEC1" and "NEC2". I've never seen any official documentation on this protocol, not even the one implied earlier in this thread giving the official lengths of zero and one bits.

The app note at [Link: mbx-usa.com] has a link to a NEC datasheet for one of their code generating chips which documents the protocol. (I think that specific chip has been discontinued.)