From: doug.dingus@gmail.com   
      
   Personally, I have used actual point sizes as they appear on the screen.   
      
   One can break this discussion into two components:   
      
   Point size.  Print out, or use a reference document and compare actual text   
   size.  Say 10pt on the ref document compared to the displayed text being   
   larger or smaller.   
      
   The other component is DPI, dots per inch as was calculated above.   
      
   For a given display, there will be a floor where the DPI is not sufficient to   
   render the font glyphs with enough fidelity to be useful.  An Apple 2 has   
   basically two DPI numbers.  One for the 40 column text and HGR, and a sort of   
   higher one for 80    
   columns and DHGR.  Both are the same vertically.   
      
   On the other extreme, a mobile will have a much higher DPI, and can display   
   much smaller glyphs.   
      
   Simply give them a reference text size on a printed document and or maybe a   
   couple, just enough to compare the intended cases and no more.   
      
   They can literally hold that up to a display and adjust the font parameters on   
   it, until it is good to go.   
      
   Display size makes this all hard, and I tend to just get physical references   
   and or point to ones I know most people can find and make adjustments from   
   there.   
      
   You can do this with a nice sans serif font, monospace type, and print out   
   font at 10, 12, 14, 16pt and pick out your Apple 2 text size you like and   
   convert it to a physical point size and be good to go talking about it to   
   others.   
      
   About the only way it goes bad is when the desired physical size is too small   
   for the DPI of a device.  In that scenario, either get the display farther   
   away,  lolol, or use a larger reference size to account for that display and   
   DPI.  Given you want to    
   specify text size on newer stuff than an Apple 2, you should not run into this   
   problem and need only to associate Apple 2 40, 80 column text to an physical   
   point size and monospaced sans serif font and be good.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)