wd'pc win closeok; xywh 0 0 300 200;cc g isigraph; pas 0 0; pshow;' NB. J6 or earlier
wd'pc win closeok; minwh 600 400;cc g isidraw flush; pshow;' NB. J802 or later
glpaint glclear ''
glpaint drawLine 10 10 590 390