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CONTRIBUTIONS/cpm-handbook/cpmsrc/FIG5-6.ASM

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+; Figure 5-6
+;
+;	WL$PUN
+;	Write Line to Punch device. Output terminates
+;	when a 00H byte is encountered.
+;	A Carriage Return is output when a Line Feed is
+;	encountered.
+;
+;	Calling sequence
+;
+;		LXI	H,BUFFER
+;		CALL	WL$PUN
+;
+;	Exit Parameters
+;
+;		HL -> 00H byte terminator
+;
+B$PUNOUT	EQU	4
+BDOS		EQU	5
+;
+CR		EQU	0DH	;Carriage Return
+LF		EQU	0AH	;Line Feed
+;
+WL$PUN:
+	PUSH	H		;Save Buffer pointer
+	MOV	A,M		;Get next character
+	ORA	A		;Check if 00H
+	JZ	WL$PUNX		;Yes, exit
+	CPI	LF		;Check if Line Feed
+	CZ	WL$PUNLF	;Yes, O/P CR
+	MOV	E,A		;Character to be output
+	MVI	C,B$PUNOUT	;Function Code
+	CALL	BDOS		;Output character
+	POP	H		;Recover Buffer pointer
+	INX	H		;Update to next char.
+	JMP	WL$PUN		;Output next char
+WL$PUNLF:			;Line Feed encountered
+	MVI	C,B$PUNOUT	;Function Code
+	MVI	E,CR		;Output a CR
+	CALL	BDOS
+	MVI	A,LF		;Recreate Line Feed
+	RET			;Output LF
+WL$PUNX:			;Exit
+	POP	H		;Balance the stack
+	RET
+