update

Author: WoodHolz

X86/02.md

@@ -0,0 +1,33 @@
+``` asm
+DATA SEGMENT
+        BUF1 DB 0A8H, 9FH, 0B4H, 25H # 注意16位数首位是字母必须开头加‘0’
+        BUF2 DB 78H, 0FFH, 0D3H, 5CH
+        BUF3 DB 4 DUP(?)
+DATA ENDS
+CODE SEGMENT
+ASSUME CS: CODE, DS: DATA
+START:  MOV AX, DATA
+        MOV AX, DATA
+        MOV DS, AX
+        LEA SI, BUF1
+        LEA DI, BUF2
+        MOV BX, OFFSET BUF3
+        MOV CX, 4
+        CLC             ;CF=0, STC CF=1
+NEXT:   MOV AL, [SI]
+        MOV DL, [DI]
+        ADD AL, DL
+        MOV [BX], AL
+        INC SI
+        INC DI
+        INC BX
+        DEC CX
+        JNC NEXT        ;ZF=0
+
+        MOV AH, 4CH
+        INT 21H
+CODE ENDS
+END START
+
+```
+