Commodore 128 System Manual page 342

RDOT
Return current position or color of pixel cursor.
RDOT (N)
where:
N
= 0 returns the X coordinate of the pixel cursor
N
= 1 returns the Y coordinate of the pixel cursor
N
= 2 returns the color source of the pixel cursor
This function returns the location of the current position of the
pixel cursor (PC) or the current color source of the pixel cursor.
EXAMPLE:
PRINT RDOT(O)
PRINT RDOT(1)
PRINT RDOT(2)
RGR
Return current graphic mode
RGR(X)
This function returns the current graphic mode. X is a dummy
argument, which must be specified. The counterpart of the RGR
function is the GRAPHIC command. The value returned by
RGR(X) pertains to the following modes:
VALUE
0
1
2
3
4
5
EXAMPLE:
PRINT RGR(O)
1
This displays the current graphic mode, in this case, standard bit
map mode.
18-14
Returns X position of PC
Returns Y position of PC
Returns color source of PC (0 to 3)
GRAPHIC MODE
40 column (VIC) text
Standard bit map
Split screen bit map
Multicolor bit map
Split screen Multicolor bit map
80 column (8563) text