From: michael.pohoreski@gmail.com   
      
   On Monday, June 7, 2021 at 8:20:18 AM UTC-7, Thomas Harte wrote:   
   > I am the author of an Apple II emulator; I recently received a bug report   
   that its pixels aspect ratio is off — e.g. in text mode, pixels are not   
   square.    
      
   AppleWin developer here.   
      
   I've never known any Apple 2's using a TVs or Apple monitors to have 1:1   
   aspect ratio (AR).  The consensus is that a 4:3 AR is the de facto standard.   
      
   Using pixels, 280/192 = 1.45... which "roughly" matches 4:3 = 1.333.   
      
   If you draw a circle you will need to use scaling to have it display without   
   it looking like an ellipse.   
      
   We had a thread about this back in 2017 called: Emulator aspect ratios?   
   * https://groups.google.com/g/comp.emulators.apple2/c/YUsAV1BX1Ks   
      
   At the time I posted this information:  (There was a bug in the original code,   
   here is the fixed version)   
      
   # Code   
      
   HGR   
   CALL-151   
   c051 n c054   
   2000:7f   
   2027:7f   
   3fd0:7f   
   3ff7:7f   
   c050 n c052   
      
   # Measurements   
      
   Apple Color Monitor   
   ===================   
   Width: 9.5"   
   Height: 7"   
   Diagonal: 12"   
      
   Franklin Color Monitor   
   ======================   
   Width: 9" or 22.5 cm   
   Height: 6.5" or 16.5 cm   
   Diagonal: 11"   
   Aspect Ratio (Width/height):   
      
   # Calculations   
      
   Apple:   
   DPI Width: 560 dots/9.5 inches = 58.94 dpi   
   DPI Height: 192 dots/7 inches = 27.42 dpi   
   Aspect Ratio (Width/Height): 9.5 / 7 = 1.35   
      
   Franklin:   
   DPI Width: 560 dots/9 inches = 62 dpi   
   DPI Height: 192 dots/6.5 inches = 29.58 dpi   
   Aspect Ratio (Width/Height): 9 / 6.5 = 1.38   
      
   Ergo, the aspect ratio is very close to 4/3 = 1.33.   
      
   Hope this helps.   
      
   m.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)