Thanks Darrel,

I got it right, it is now send back the letters test with this code...

'WRITE TO EEPROM
OWOUT ibutton,1,[$CC,$0F,$00,$00] 'Write to scratchpad
OWOUT IBUTTON,0,[$54,$65,$73,$74] 'Write characters "test"
OWout IBUTTON,1,[$CC,$AA] 'get ready to read scratchpad
owin ibutton,0,[Taddr[0],Taddr[1],ES] 'read back the scratchpad to get the Authorisation code
owout ibutton,1,[$CC,$55] 'Write back the contents of the target address & E/S register
owout ibutton,0,[Taddr[0],Taddr[1],ES] 'to allow copy scratchpad to take place.

PAUSE 25

'READ FROM EEPROM
OWOUT ibutton,1,[$CC,$F0,$00,$00]
FOR MEM=1 TO 4
OWIN IBUTTON,0,[RESULT]
SEROUT2 PORTB.0,16416,[RESULT]
PAUSE 100
NEXT MEM

END

Thanks Chris