Looking for info on the internal workings of the 41's IR printer module

[emece67]

Hi all,

I'm aware of the IR protocol used by hp's IR printers, and also aware that the ROM for the IR printer module is available. But, has anybody a clue about the hardware inner workings of such module? How does the 41 control the IR LED? Does the nut processor directly access the LED or has the module some counters/timers to do so?

I've searched the forum (and also the documents in TOS) to no avail.

Thanks & regards.