How Does The 640x480 Screen Size Scale In The Original Baldur's Gate?

I really liked how the inventory in the 'Full Screen' scaled in Original Baldur's Gate.

How was this done as to where the image was not warped (I have tried to emulate this effect but I have failed with warped results)? I have figured out that my 1633x768 Laptop Screen scales the 'in game' 640x480 (resolution?) image by 1.6 (and then flanks two black horizontal bars on the edges of my screen) when I 'Full Screen' Baldur's Gate Tales of the Sword Coast.

I am wondering if the inventory in Baldur's Gate Enhanced Edition could be improved to scale up appropriately (for a variety of screen sizes) so that the Icons and and such look much better (in my opinion anyway) than they currently do, tiny and microscopic..?