Mr. Houston,

The cost is not the concern here. The concern is that other companies that deal with 39xx expansion can say that they support the wiring, pinout, whatever for their devices. Since this is somewhat a simple device (not nearly as complicated as wifi, mem, etc..), amplifying IR, the interface should be as simple too. If there is a wide difference in the 39xx expansion then that limitation would be projected to the other companies as well. As far as I know, my wifi from netgear, is compatible out of the box for the 39xx. As a matter of fact the netgear website says this:

Compaq iPAC 3870, 3865, 3875

heck, its not even spelled right. But I bought it and it works like a charm. The expansion pack is not explicitly made for the 39xx. Therefore implying backward compatibility. There was a post saying that the 39xx has some wiring differences therefore the incompatibility between TV Remote and PDA-ir. I'm just saying, if this is indeed the case, which I don't doubt, then it would effect everybody making expansion cards, right?.

That's just what I'm thinking.