AT&T 6300 Programmer's Manual page 406

POINT
Function
Syntax
x,y
n
Remarks
7-250
With two arguments (x,y) returns the color
number of a pixel on the screen. If one
argument (n) is given, returns current
graphics coordinate. (Graphics Mode only).
POINT
(0)
are the absolute coordinates of the pixel to be referenced. If
the point is out of range, the value -1 is returned.
'n' may have the values 0, 1, 2, or 3:
0: Returns the current physical x coordinate
1: Returns the current physical y coordinate
2: Returns the current world x coordinate if a WINDOW
statement has been used, other-wise returns the same value
as the POINT(O) function.
3: Returns the current world y coordinate if WINDOW is
active, otherwise returns the same value as the POINT(I)
function.
vl+POINT (x,y)
returns the color number of the specified pixel
into the integer variable vI.