直接看不懂一个小程序是怎么实现的?各位大侠有空给看看!非常感谢....

[jerk66]

程序就是实现:当结束时,把Sum保存起来...,想不通

.model tiny
.code
.286
org 100h

Start:
push bp <---------看不懂,不知道bp指向什么
...... <---------省略无关代码
mov Sum,20
pop bp
call Save
ret

Save PROC
push ds <---------看不懂
mov ax, 1203h <---------看不懂
int 2fh <---------看不懂,中断2fh,的1203h是做什么的?
lds dx, ds:[bp-1ah] <---------看不懂,是怎么找到当前运行文件名的?
mov ax, 3d01h ;Open file
int 21h
mov bx, ax ;Save file handle
pop ds

mov ax, 4200h ;Move reading pointer
xor cx, cx
mov dx, offset Sum-Start
int 21h
mov ah, 40h ;Write
lea dx, sum
mov cx, 2
int 21h
mov ah, 3eh ;Close file
int 21h
ret
Save ENDP
sum db 0
END Start

[jerk66]

qq:124338778,多多交流

[Yofoo]

INT 2F U - DOS 3.0+ internal - GET DOS DATA SEGMENT
AX = 1203h
Return: DS = data segment of IBMDOS.COM/MSDOS.SYS