The X Size box contains a value which specifies the width of the page in master units. If the paper size is predefined, UniTool provides this value; however, if the paper size is defined by the user, the minidriver developer must specify this value.
For the Diconix 150 Plus printer, the value that appears in the X Size box is 8160. UniTool determined this value by multiplying the paper width (8.5 inches) by the horizontal master unit (960 dots per inch).
For the HP LaserJet IIP printer, the value that appears in the X Size box is 2550. UniTool determined this value by multiplying the paper width (8.5 inches) by the horizontal master unit (300 dots per inch).