Thanks for your answers, but, sorry, it looks like I didnt explain myself very well
I dont want to see the UCS icon like the attached image, nor the viewcube... I just want plain "2d modelspace" back rather than the 3d parallel or 3d perspective projections.
I'd already tried the setting the ucs to world, and plan to world, but that leaves the viewcube and the ucs as a brightly coloured object in the corner of my screen