How to add a top vision to the tools, besides iso, left, right, front and back?
The Top view is a default toolbar button on the Views toolbar. If it is missing, go to View>Toolbars and click on Reset All.
You want to be careful with that Dave, Reset all will do just that, Reset All toolbars including any you may have modified deliberately. For example I use the measurement toolbar and add my tools to that. Reset all would remove all my tools and I’d have to rebuild it again.
If a tool is missing from a toolbar, select the toolbar in the list and hit Reset and it will reset just that toolbar, restoring any missing tool.
So in this instance, if the Top view is missing from the toolbar,
Go View/Toolbars in the dialog that opens scroll down to Views an highlight it with a click then click the reset button and the Top view button will reappear.