;----------------------------------------------------------------------------
;              x86 - Dos - Assembly Language Programming                    ;
;                                                                           ;
; Written by: John A Lyons                                                  ;
; Email     : sysop@megablast.8k.com                                        ;
; Page      : http://asmsource.8k.com                                       ;
; Date      : 16 September 1997                                             ;
; Purpose   : Executes a program, shows use of dos routines 4bh, int 21h    ;
;             This exectues a program called tasm.exe                       ;
;                                                                           ;
;----------------------------------------------------------------------------
; compile with tasm:
;
;C:\ASM\SOURCE>[f] [QE] tasm exec.asm
;Turbo Assembler  Version 4.0  Copyright (c) 1988, 1993 Borland International
;
;Assembling file:   exec.asm
;Error messages:    None
;Warning messages:  None
;Passes:            1
;Remaining memory:  424k
;
;
;C:\ASM\SOURCE>[f] [QE] tlink /t exec.obj
;Turbo Link  Version 7.1.30.1. Copyright (c) 1987, 1996 Borland International
;
;C:\ASM\SOURCE>[f] [QE] exec
;

.286c
CODE_SEG_A	SEGMENT
		ASSUME	CS:CODE_SEG_A, DS:CODE_SEG_A
		ORG	100h
START           PROC    NEAR
		JMP	SHORT LOC_1
		DB	90H
LOC_1:
                lea sp,stk
                MOV AH,4AH
                MOV BX,(OFFSET STK - OFFSET START + 10FH )/16
                INT 21H
                JC BEND
                lea dx,PNAME
                lea BX,PARS
                MOV AX,4B00H
                INT 21H
AEND:
                MOV AH,4CH
                INT 21H
BEND:
                MOV AX,0B800H
                MOV ES,AX
                MOV ES:[0],AH
                JMP AEND

PNAME           DB 'TASM.EXE',0
PARS            Dw OFFSET ENVIR
                Dw OFFSET CMDLINE,0
                Dw OFFSET FCB1,0
                Dw OFFSET FCB2,0

CMDLINE         DB 0,0DH
FCB1            DB 0
                DB 11 DUP ('?')
                DB 25 DUP (0)
FCB2            DB 0
                DB 11 DUP (' ')
                DB 25 DUP (0)
ENVIR           DB 'PATH=',0
                DB 'COMSPEC=A:\CO