The origin of the graphical user interface was actually elswhere. The https://en.wikipedia.org/wiki/Semi-Automatic_Ground_Environm... system had a display system with a "graphical user interface" and a "ligth gun" (i.e. pointing device) by 1958; also e.g. https://en.wikipedia.org/wiki/Sketchpad had similar features in 1963; but these were CRT displays with vector drawings. The Alto in 1973 in contrast had a bitmaped screen and the first GUI following a desktop metapher (see e.g. https://www.microsoft.com/en-us/research/publication/alto-pe... or http://bwlampson.site/38-AltoSoftware/Abstract.html).