I don't think in HD Box, you will be able to watch one channel and record another. Either you watch and record the same channel or record a channel when you are away. Technically there is a possibility to record all the channels in a mux at the same time. ie, all the channels in a transponder having same freq, polarization but different PIDs can be recorded. But it needs more horsepower and not sure if the USB 2 can handle so much of data transfer. So, they will limit recording one channel at a time in HD box.