TITLE Mov instruction examples      (mov_ex.asm)

; Program Description:  move insruction examples
; Author: Christopher Young
; Date Created: 9/23/2003
; Last Modification Date:

;*********************************************************************
; include files
;*********************************************************************
INCLUDE Irvine32.inc


;*********************************************************************
; (insert symbol definitions here)
;*********************************************************************



;*********************************************************************
;Data section: Variables, initialized arrays, etc...
;*********************************************************************
; initialized data
.data

;Use of label directive
var1_8  LABEL BYTE
var1_16 LABEL WORD
var1_32 LABEL DWORD

var1      BYTE 12h,34h,56h,78h
var2      BYTE 0AAh,00h,00h,10h
var3_32   LABEL DWORD
var3      WORD 1234h,5678h

; unitialized data
.data?
var4      BYTE 100 dup(?)  ; reserve 100 bytes of space

;*********************************************************************
; Code section
;*********************************************************************
.code
main PROC

; Insert executable instructions here:

; ;  zero the registers we will be using
;    mov  eax, 0
;    mov  ebx, 0
;    mov  ecx, 0
;    mov  edx, 0
;    call DumpRegs  ; verify these are zero
;
; ; The assembler does typechecking on the variables (nice)
; ; to overide this, use <type> PTR before the variable name.
;
;    mov  al,var1
;    mov  bx,WORD PTR var1
;    mov ecx,DWORD PTR var1
;    mov dx,var3
;
;    call DumpRegs  ;  display register contents.
;
;  ;  zero the registers we will be using
;     mov  eax, 0
;     mov  ebx, 0
;     mov  ecx, 0
;     mov  edx, 0
;     call DumpRegs  ; verify these are zero
;
;  ; Alternately we could label our data differently
;     mov  al,[var1_8+1]
;     mov  bx,[var1_16+1]
;     mov ecx,[var1_32+1]
;     mov edx,[var3_32+1]
;     call DumpRegs  ; verify these are zero
;
;  ; movzx (move zero extend)
;   ;  zero the registers we will be using
;      mov  eax, 0
;      mov  ebx, 99999999h
;      mov  ecx, 0
;      mov  edx, 0
;      call DumpRegs  ; verify these are zero
;
;      mov   ax, 0AB7Dh
;      movsx ebx,  al    ; 8 to 32 bits
;
;      call DumpRegs  ; verify these are zero


 ; movsx (move sign extend)


 ; Indirect operands & use of the OFFSET directive.
 ;  zero the registers we will be using
    mov  eax, 0
    mov  ebx, 0
    mov  ecx, 0
    mov  edx, 0
    call DumpRegs  ;  display register contents.

    ; try edx for an indirect read/write of memory
    mov  edx, OFFSET var1  ;edx points to var1 (within the data segment)
    mov  eax,[edx]         ;read memory where edx points
    mov  bx,[edx]
    mov  cl,[edx]

    call DumpRegs  ;  display register contents.



	exit	; exit to operating system
main ENDP



;*********************************************************************
; END OF CODE
;*********************************************************************

END main