The map is supposed to show an area about ten tiles in each direction from the PC wherever he goes. This may include inaccessible places when they are close enough to the player's path. In my experience, this is just a little larger than the view on the screen when playing the game.
If a map had no blocked areas, and you started north from the SW corner ten tiles in, moved over to tile 30 when you reach the northern border and walked south, then moved to tile 50, etc., you would cover a 200 x 200 tile map in ten passes. The map would show that you've "seen it all" when in reality there would be thin verticle areas which did not show on the screen at tiles 20, 40, 60, etc. If you did a similar experiment using the horizontal paths (10, 30, 50, 70, etc.) the unviewed strips would be larger because the viewing screen is not as tall as it is wide.
Your actual results my differ slightly from this because your map is not 32 x 32 movement tiles.
Hope that helps.