I tried the A1 with Vivitar 28-85 f/3.5-4.5. In metered manual mode, the f stop display would go to f/3.5 even when zoomed to 85mm which the max aperture is 4.5. Do I need to compensate when zooming or just set the aperture ring to what the display says?

The problem you do have is that in manual the indicated aperture in the viewfinder for the set shutter speed may not be correct depending on how the aperture ring on the lens works.
