difference between command1 and command1_p

[DrD]

The user guide offers this (Program Commands Page 637):

Drawing

There are 10 built-in graphics variables in the HP Prime, called G0–G9. G0 is always the current screen graphic.
G1 to G9 can be used to store temporary graphic objects (called GROBs for short) when programming applications that use graphics. They are temporary and thus cleared when the calculator turns off.
Twenty-six functions can be used to modify graphics variables. Thirteen of them work with Cartesian coordinates using the Cartesian plane defined in the current app by the variables Xmin, Xmax, Ymin, and Ymax.
The remaining thirteen work with pixel coordinates where the pixel 0,0 is the top left pixel of the GROB, and 320, 240 is the bottom right. Functions in this second set have a _P suffix to the function name.

-Dale-