AT&T 6300 Programmer's Manual page 507

Syntax
(xl,yl)
-(x2,y2)
Remarks
WINDOW
Statement
Permits the redefinition of the screen
coordinates. (Graphics Mode only.)
WINDOW [ [ SCREEN ] (xl, y 1) - (x2, y2) ]
(x1,y1) represent the upper-left coordinates of the window.
(x2,y2) represent the lower-right coordinates of the window.
These coordinates may be any single precision floating
point number.
WINDOW allows you to draw lines, graphs, or
objects in space not bounded by the physical
limits of the screen. This is done by using
arbitrary programmer-defined coordinates
called "world coordinates."
A world coordinate is any valid single
precision floating point number pair. GWBASIC
then converts world coordinate pairs
into the appropriate physical coordinate pairs
for subsequent display within screen space. To
make this transformation from world space to
the physical space of the viewing surface
(screen), GWBASIC must know what portion
of the unbounded (floating point) world
coordinate space contains the information you
want to be displayed.
This rectangular region in world coordinate
space is called a window.
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