Commodore 128 System Manual page 279

The clear parameter specifies whether the bit mapped screen is
cleared (equal to 1) upon running the program, or left intact
(equal to 0). The s parameter indicates the starting line number of
the split screen when in graphic mode 2 or 4 (multicolor or
standard bit map split screen modes). The default starting line
number of the split screen is 19.
When executed, GRAPHIC 1 -4 allocates a 9K-bit mapped area.
The start of BASIC text area is moved above the bit-map area,
and any BASIC program is automatically relocated. This area
remains allocated even if the user returns to TEXT mode
(GRAPHIC 0). If the clear option is specified as 1, the screen is
cleared. The GRAPHIC CLR command deallocates the 9k, bit
mapped area making it available once again for BASIC text. Any
BASIC program is relocated.
EXAMPLES:
GRAPHIC 1,1
Select standard bit map mode and clear the bit map.
GRAPHIC 4,0,10
Select split screen multicolor bit map mode, do not clear the bit
map and start the split screen at line 10.
GRAPHIC 0
Select 40 column text.
GRAPHIC 5
Select 80 column text.
GRAPHIC CLR
Clear and deallocate the bit map screen.
HEADER
Formats a diskette
HEADER "diskname" [,l i.d.] [,Ddrive number]
[<ON | ,>Udevice number]
17-37