how to compare data

[aratti]

IT DOES COMPARE 33 AND 33 BUT NOT OTHER 7 BYTE WHY ?

Simply because you have still left out of the FOR/NEXT loop the compare instruction!

SCAN:
FOR ADR = 0 TO 7

I2CREAD SDAT,SCLK,$A0,ADR,[KEY] 'same data  as data eeprom  
PAUSE 10
READ ADR,KEY1    ' same data as external eeprom 24c02
PAUSE 100
IF (KEY = KEY1) THEN , here is the problem it does hight rely even i put diffirent data in key and key1
 HIGH RELY 
PAUSE 1000
LOW RELY
ENDIF
NEXT ADR

See my correction to your last code posted or just copy and paste the code in post #5 (the one with my correction in read) and try it.

Al.