LCDINI 		EQU 9CF0h
TXTPOS		EQU 9DA0h
COUNT 		EQU 7Eh
PARITAET 	EQU 7Fh
DP2L		EQU 7Ch

; T1-ISR
		ORG 001Bh
		LJMP TISR

; P1.4-ISR
		ORG 004Bh
		LJMP PISR

; Serielle Schnittstelle-ISR
		ORG 0023h
		LJMP SISR

; P1.0-ISR
		ORG 0053h
		CLR TF2
		SETB ET2
		RETI

; P1.1-ISR
		ORG 005Bh
		CLR ET2
		RETI

; P1.2-ISR
		ORG 0063h
		LJMP TIDYUP

; T2-ISR
		ORG 002Bh
		LJMP T2ISR


; Hauptprogramm
		ORG 0400h
		MOV PSW, #00 ; Registerbank 0
		MOV P4, #0FFh
		MOV SP, 7Fh
		SETB P1.0
		SETB P1.1
		SETB P1.2
		SETB P1.3
		SETB P1.4
		SETB P1.7
		MOV R0, #00
		MOV R1, #00
		MOV R2, #00
		MOV R3, #00
		MOV R4, #00
		MOV R5, #00
		MOV COUNT #0Fh ; Counter initialisieren
		MOV PARITAET, #00h ; Paritaetsspeicher initialisieren
		MOV DPTR, #1000h ; LCD initialisieren
		MOV DP2L, #00h
		MOV A, #0Fh
		LCALL LCDINI
		MOV DPTR, #1069h ; auf erste Adresse einstellen
		MOV SCON, #D0h
		CLR BD
		ORL PCON, #80h ; SMOD auf 1
		MOV TMOD, #10h ; Timer 1 als 16-Bit-Zeitgeber initialisieren
		MOV TH1, #0FBh
		MOV TL1, #1Eh
		SETB TR1	   ; Timer 1 starten
		MOV IP1, #08h  ; Prioriäten
		MOV IP0, #08h
		MOV IEN0, #00
		MOV IEN1, #00
		CLR IEX3
		SETB I3FR
		SETB EX3
		CLR IEX4
		SETB EX4
		CLR IEX5
		SETB EX5
		SETB EAL
		LCALL AUSGAB
		CLR TF1
		SETB ET1
		SETB I2FR ; P1.4 auf pos. Flanke interruptbehandeln
		CLR IEX2
		SETB EX2
		SETB ES
		SETB EAL ; generelle Interrupt-Freigabe

LOOP:	JB P1.3, LOOP
		LCALL AUSGAB
		SJMP LOOP

LCDAUS:	DJNZ COUNT, AUS
		MOV COUNT, #0Fh
		MOV DPTR, #1069h ; wieder auf Zeilenanfang stellen
AUS:	LCALL TXTPOS
		RET
PISR:	PUSH PSW
		PUSH ACC
		SETB TI
		RETI
TISR: 	PUSH ACC
		PUSH PSW
		MOV A, TL1
		ADD A, #22h; +4
		MOV TL1, A
		MOV TH1, #0FBh
		POP PSW
		POP ACC
		RETI
SISR:	PUSH PSW
		PUSH ACC
		JNB TI, EMPF
		CLR TI
		MOV A, DP2L
		CJNE A, #0Fh, HIHI
		CLR A
		SJMP BACK
HIHI:	PUSH DPL
		MOV DPL, DP2L
		CLR A
		CLR EAL
		LCALL TXTPOS
		SETB EAL
		MOV C, P
		MOV TB8, C
		JNB P1.7, BUND
		CPL TB8
BUND:	MOV SBUF, A
		INC DP2L
		POP DPL
		SJMP BACK
EMPF:	MOV A, SBUF
		MOV P5, A
		MOV C, RB8
		JNB P, EXOR
		CPL C
EXOR:	JNC GUT
		MOV PARITAET, #01h ; Fehler aufgetreten
		MOV A, #40h
		LCALL LCDAUS
		SJMP BACK
GUT:	MOV PARITAET, #00h	; kein Fehler aufgetreten
		CJNE A, #20h, NEXT ; <20h?
NEXT:	JC BACK
		CJNE A, #80h, NETT; >79h?
NETT:	JNC BACK
		LCALL LCDAUS
BACK:	CLR RI
		POP ACC
		POP PSW
		RETI
TIDYUP:	JB ET2, BACKGO
		MOV R0, #00
		MOV R1, #00
		MOV R2, #00
		MOV R3, #00
		MOV R4, #00
		MOV R5, #00
BACKGO:	RETI
T2ISR:	PUSH ACC
		PUSH PSW
		CLR C
		MOV A, R0
		ADD A, #01
		DA A
		MOV R0, A
		CJNE R0, #00h, RETURN
		MOV A, R1
		ADD A, #01
		DA A
		MOV R1, A
		CJNE R1, #60h, GOONN
		MOV R1, #00
GOONN:	CJNE R1, #00h, RETURN
		MOV A, R2
		ADD A, #01
		DA A
		MOV R2, A
		CJNE R2, #60h, RETURN
		MOV R2, #00
RETURN:	MOV A, R0
		MOV R3, A
		MOV A, R1
		MOV R4, A
		MOV A, R2
		MOV R5, A
		POP PSW
		POP ACC
		RETI
AUSGAB:	PUSH DPH
		PUSH DPL
		PUSH PSW
		PUSH ACC
		MOV DPTR, #1000h
		MOV A, R5
		SWAP A
		LCALL ASCII
		CLR EAL
		LCALL TXTPOS
		SETB EAL
		MOV A, R5
		LCALL ASCII
		CLR EAL
		LCALL TXTPOS
		SETB EAL
		MOV A, #3Ah
		CLR EAL
		LCALL TXTPOS
		SETB EAL
		MOV A, R4
		SWAP A
		LCALL ASCII
		CLR EAL
		LCALL TXTPOS
		SETB EAL
		MOV A, R4
		LCALL ASCII
		CLR EAL
		LCALL TXTPOS
		SEB EAL
		MOV A, #3Ah
		CLR EAL
		LCALL TXTPOS
		SETB EAL
		MOV A, R3
		SWAP A
		LCALL ASCII
		CLR EAL
		LCALL TXTPOS
		SETB EAL
		MOV A, R3
		LCALL ASCII
		CLR EAL
		LCALL TXTPOS
		SETB EAL
		POP ACC
		POP PSW
		POP DPL
		POP DPH
		RET
ASCII:	PUSH PSW
		ANL A, #0Fh
		CJNE A, #0Ah, NEXT
NXET:	JC Ziffr
		ADD A, #0Fh
Ziffr:	ADD A, #30h
		POP PSW
		RET
		END