rjexp20.asm

显示屏相关程序实现显示屏点亮控制等功能.

CRLF   MACRO
        MOV          AH,02H
        MOV          DL,0DH
		INT          21H                ;回车换行宏定义
        MOV          AH,02H
        MOV          DL,0AH
        INT          21H
ENDM
DATA   SEGMENT
DTABUF  DB  128 DUP(?)         ;DTA磁盘传送缓冲区
FNAME  DB   '*.*',0           ;ASCIIZ串,匹配任意文件
DATA   ENDS
STACK  SEGMENT
STA     DW    32 DUP(?)
TOP			DW  ?             ;堆栈定义
STACK		ENDS
CODE      SEGMENT
ASSUME  CS:CODE,DS:DATA,ES:DATA,SS:STACK
START:		MOV	AX,DATA
			MOV	DS,AX           ;段寄存器和堆栈初始化
			MOV	ES,AX
			MOV	SP,TOP
			MOV	DX,SEG DTABUF
			MOV	DS,DX
			MOV	DX,OFFSET DTABUF
			MOV	AH,1AH
			INT 		21H            ;设置磁盘传送缓冲区DTA
			MOV	DX,OFFSET FNAME
			MOV	CX,0           ;搜索第一个匹配文件,CX
			MOV	AH,4EH        ;属性为0则仅找一般文件
			INT 		21H
			JC		EXIT
XXX:		CRLF
			MOV 	CX,0
			MOV 	SI,OFFSET DTABUF+1EH
UUU:		LODSB
			OR	AL,AL
			JZ	 VVV
			INC 		CX
			JMP 	UUU
VVV:		MOV 	DX,OFFSET DTABUF+1EH
			MOV 	BX,1
			MOV AH,40H
			INT 		21H
ZZZ:		MOV 	AH,4FH
			INT 		21H
			JNC 	XXX
EXIT:		MOV 	AX,4C00H
			INT 21H
CODE ENDS
 END START