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P. 127
MOV P2,A
MOV A,COUNTER
ADD A,#BUFFER
MOV R0,A
MOV A,@R0
CALL TAKE_DISPLAYCODE
CPL A
MOV P0,A
RET
CHECK_KEY: A,P2
MOV A
CPL A,#01111000B
ANL A,#00001000B,$1
CJNE A,#00H
MOV $E
JMP
$1: A,#00010000B,$2
CJNE A,#04H
MOV $E
JMP
$2: A,#00100000B,$3
CJNE A,#08H
MOV $E
JMP
$3: A,#010000000B,$4
CJNE A,#0CH
MOV $E
JMP
$4: A,COUNTER
RET A,KEYBUF0
$E: A,KEYBUF1
ADD PRESS
XCH
XCH COUNTER
SETB A,COUNTER
RET
CHANGE_DISPLAY:
INC
MOV
