Johnsfine: thanks for all that. it worked in the sense that i could try all 256 codes, and I can confirm that no discrete on/off codes exist.

it was also a pretty scary experience, a few wierd screens came up, some of them you could edit values on too. I don't think i have buggered anything up, but time will tell.

thanks for your help - i can't believe manufacturers make these things without discrete codes, for the record i think it sucks.