Table of Contents

SCREEN

C64 C128

The SCREEN command switches between multiple logical screens by changing the Video Matrix Base Address.

Syntax

SCREEN <screen_number>

Where <screen_number> must be a value between 0 and 15. The value multiplied by $0400 (decimal 1024) will be the new Base Address within the currently selected VIC bank. The default VIC bank is 0 and the default screen number is 1, therefore the default Base Address is $0400 (decimal 1024).

Note

The command has effect on the Commodore-64 and 128 only.

Warning

The SCREEN command updates various KERNAL variables and pointer tables, which consumes considerable amount of CPU cycles and therefore it is not suitable for quickly switching between screens, for example when displaying double-buffered graphics. If speed is crucial in your program, consider simply using POKE to switch between screens.

Example

DIM a$ AS STRING * 1
PRINT "this is screen 1"
PRINT "press key to switch"
REM save cursor position
x = POS() : y = CSRLIN()
REM wait for keypress
DO
  GET a$
LOOP WHILE LEN(a$) = 0
REM switch screen
SCREEN 8
PRINT CHR$(147)
PRINT "this is screen 8"
PRINT "press key to go back"
REM wait for keypress
DO
  GET a$
LOOP WHILE LEN(a$) = 0
SCREEN 1
REM restore cursor position
LOCATE x, y