It's not just a matter of the code groups that the remote sends out; Kenwood uses a 36.6 kHz base clock signal, and Pioneer (I think) uses 39.3 kHz. On a domestic device such as a TV, this means that the device doesn't even "hear" this alien remote, it's talking "too fast".
Unless the domestic IR receiver on the empeg is interrogated by software and there is no dedicated IC for decoding at a fixed base rate, I doubt there is even a way that the empeg can even recognise the frequency of the remote when sending. I would be quite happy to be proven wrong, however
The best thing to do (IMHO) is to use irDA compliant devices to talk to the second receiver in the empeg. That way, at least the codes and the Tx/Rx rates are standardised, and you just need to write a device driver to handle the port...
One of the few remaining Mk1 owners...
#00015