BK uses a certain font size for the screens that is built into the program.
The Edit screen has the most size options currently, and that is based on the size of the BK window.
The font size gets larger on Edit as the window is larger.
From the main BK screen you can pick Help, then
640 by 480
800 by 600
1024 by 768
1440 by 900
BK Edit screen has 3 different font sizes and the font gets larger for each of those (except not for 1024 by 768)
The fields get longer for 1024 by 768 but the font stays the same as for 800 by 600
Some other screens get a larger font (the Source screen as 2 font sizes)
Most screens do not get a larger font at this time.
I will need to work on the other screens to make the fonts larger as the screen is larger.