pgm8_1b.asm

汇编编程艺术

; Well-formatted vs. Poorly formated programs.
;
; An example of a *really* poorly formatted program.
; Although this is an extreme example, it is possible
; to make your program difficult to read by only
; messing up the format of a few lines.






dseg		segment	para public 'data'

	; Some type definitions for the variables we will declare:

uint typedef				word		;Unsigned integers.
integer			  typedef	sword	;Signed integers.


	; Some variables we can use:

j	integer	?
	k			integer		?
		l integer ?

			u1		uint	?
u2 uint					?
	u3					uint	?

							dseg ends

			cseg segment		para public 'code'
assume cs:cseg, ds:dseg

Main		proc
 mov ax, 							dseg
mov		ds, ax
  mov	es, 								ax

						; Initialize our variables:

		mov	j, 3
 mov k, 					-2

mov	u1, 						254
		mov	u2, 22

					; Compute L := j+k and u3 := u1+u2

 mov			ax,						J
add							   ax, 		 K
 mov									L, ax

   mov ax, 			u1 ;Note that we use the "ADD"
     add 			ax,u2 ; instruction for both signed
       mov	u3, 				ax ; and unsigned arithmetic.





		Quit: mov		ah, 4ch ;DOS opcode to quit program.
int							21h ;Call DOS.
	Main endp

						cseg	     ends

				sseg		segment	para stack 'stack'
stk byte 1024 dup ("stack   ")
						sseg		ends
							end	Main