Yea, I'm doing similar communication with the HP and my current
project.  It does NOT only know the kermit protocal, it may also use
asynchronos serial communication, at least through the wired port, I'm
not sure if it works with the IR port though.  The XMIT command sends a
string on the first level of the stack, the SRECV command takes the
number off of level one of the stack and receives that many characters
in the buffer, I've got some more prgramming info if you'd like it.  as
I just read in one of the replies, the IR port is also inverted so that
would require it to always be on (which would drain a bunch of power) in
an asychronos state of affairs, correct me if I'm wrong on that....


Jon

Don Holtz wrote:
>
> Does anyone have info on the serial protocol that HP uses to implement
> their infra-red serial interface - for calculators and palmtops.
>
> I have an HP-48S, and several HP palmtops that I would like to use to talk to
> a PIC.
>
> Any ideas?
>
> Cheers,
> Don