Page 128 -
P. 128
CJNE A,#04H,$E
MOV COUNTER,#00H
JNB PRESS,$1
CLR PRESS
JB OPEN,$E
MOV A,KEYBUF1
XRL A,KEYBUF0
JNZ $1
SETB CHANGE
$E:
RET
$1:
CLR OPEN
RET
END
