;
; CPASM01S.ASM
; written by Keith Fenske
; Saturday, 9 March 2002
; Copyright (c) 2002 by Keith Fenske.  All rights reserved.
;
; This Intel 80x86 assembly language program prints two lines of output with
; my name and my age.  (The age is wishful thinking: a joke!)  Both lines are
; written with a single string.  The DOS function code 40h is used for the
; output and requires three parameters:
;
;   BX register = 1 when writing to standard output
;   CX register = number of bytes to write
;   DX register = address of first byte to write
;
[BITS 16]               ; set 16-bit code generation
[ORG 0100H]             ; set address of first instruction in COM file

CR  EQU  0Dh            ; carriage return character
LF  EQU  0Ah            ; line feed character

[SECTION .text]         ; start code (instruction) section

START:
    mov  bx,1           ; DOS file handle 1 is standard output
    mov  cx,length      ; length of string in bytes
    mov  dx,string      ; address of first byte in string
    mov  ah,40h         ; DOS function code for write string
    int  21h            ; call DOS

    mov  ah,4Ch         ; DOS function code to exit program
    mov  al,0           ; pass this value back as ERRORLEVEL
    int  21h            ; call DOS (does not return)

[SECTION .data]         ; start data section
;
; There is no termination character for the following string.  The length of
; the string is calculated by the EQU statement.
;
string   db   "My name is Keith Fenske.", CR, LF
         db   "I am 21 years old (joke!).", CR, LF
length   equ  $ - string
;
; End of CPASM01S.ASM
;