Last Updated or created 2023-08-21

Below you can find the files in a zip for writing assemby machine code in dosbox.

I’ve got mine extracted in ~/projects/dos

To automount this i’ve edited

~/.dosbox/dosbox-*.conf
;-------- bottom part
[autoexec]
# Lines in this section will be run at startup.
# You can put your MOUNT lines here.

mount c: /home/myusername/projects/dos
c:

The files

• A.BAT – Runs editor, masm,linker (start with a<space>progname
• DEBUG.COM – msdos debugger
• EXE2BIN.EXE – exe to com (if segments allow)
• GFX.ASM – example template (see below)
• LINK.EXE – masm linker
• MASM.EXE – masm compiler
• Q* – editor stuff
• Q.EXE – editor
• SR.EXE – sourcer
• SYMDEB.EXE
• TASM.EXE – turbo assembler
• TD.EXE – turbo debugger
• TLINK.EXE – turbo linker

Template

; everything in 64k CS, DS, and SS are the same
.model small
; start pointer
.stack 100h
.code
start:
	; set mode 13 (320x200 * 265 colors palette)
    mov ah,0	
    mov al,13h
    int 10h

    ; set pixel in the middle color 2 (cyan)
    mov ah,0ch
    mov al,2
    mov cx,160
    mov dx,100
    int 10h

	; wait key input
    mov ah,0
    int 16h

	; set mode back to text
    mov ah,0
    mov al,3
    int 10h

	; exit to dos
    mov ax,4c00h
    int 21h
end start

Usage

start dosbox
a gfx (edit gfx.asm example)
esc, q, e
gfx (run program)