sy14-3-2.asm

分别为产生步长为1的三角波

SSEG SEGMENT STACK
     DB 100 DUP(?)
SSEG ENDS
DATA	SEGMENT	
DATA	ENDS
CODE 	SEGMENT
	ASSUME	CS:CODE,DS:DATA

START:	MOV  AX,DATA
	MOV  DS,AX
	MOV  DX,9800H
NEXT:	MOV  AL,255
	OUT  DX,AL
	CALL DELAY1
	MOV  AL,0
	OUT  DX,AL
	CALL DELAY
	JMP  NEXT
	
	
DELAY   PROC NEAR
	PUSH CX
	PUSH AX
	MOV  CX,12000
ECHO1:	MOV  AX,10000
ECHO2:	DEC  AX
	JNZ  ECHO2
	LOOP ECHO1
	POP  AX
	POP  CX
	RET
DELAY ENDP

	
DELAY1  PROC NEAR
	PUSH CX
	PUSH AX
	MOV CX,4000
GOON1:	MOV AX,10000
GOON2:	DEC AX
	JNZ GOON2
	LOOP GOON1
	POP  AX
	POP  CX
	RET
DELAY1 ENDP


CODE	ENDS
END	START