The rythmn guitar and lead you are about to hear are both played by Mark.
In this case (early Dire Straits), he often used the strat on the 2nd pickup position (from lower to upper), the Orange Squeezer as a compressor and, on this particular tune, a lot of a specific type of reverb with a spring on it's tank, which gives this sord of bouncy tone (of course when added to mark's playing style).