I'm pretty certain that .model small
and seg
are artefacts of an earlier age when the x86 architecture was truly segmented (into 64K chunks).
The masm32
IDE doesn't like them very much at all (not unexpected since it's far more common nowadays to be doing 32-bit flat model code).
The problem lies in the fact that the bin\assmbl.bat
file is being used by the editor to assemble the file and it contains the line:
\masm32\bin\ml /c /coff %1.asm > \masm32\bin\asmbl.txt
(with the /coff
option). This is what's making the assembler complain.
You can get it to work by reverting to the command line. Assuming your file is tst.asm
, use the following commands:
c:\masm32\bin\ml.exe /c tst.asm
c:\masm32\bin\link16 tst.obj.tst.exe,,,,
and you'll have a tst.exe
that works fine.
The following transcript shows that this works:
C:\masm32> type tst.asm
.model small
.stack
.data
message db "Hello world!", "$"
.code
_main proc
mov ax,seg message
mov ds,ax
mov ah,09
lea dx,message
int 21h
mov ax,4c00h
int 21h
_main endp
end _main
C:\masm32> bin\ml.exe /c tst.asm
Microsoft (R) Macro Assembler Version 6.14.8444
Copyright (C) Microsoft Corp 1981-1997. All rights reserved.
Assembling: tst.asm
C:\masm32> bin\link16 tst.obj,tst.exe,,,,
Microsoft (R) Segmented Executable Linker Version 5.60.339 Dec 5 1994
Copyright (C) Microsoft Corp 1984-1993. All rights reserved.
C:\masm32> tst.exe
Hello world!
Alternatively, the editor is very configurable. If you open up the menus.ini
file for editing (back it up first, I shouldn't need to tell you that) and change:
&Assemble ASM file,\MASM32\BIN\Assmbl.bat "{b}"
to:
&Assemble ASM file,\MASM32\BIN\Assmbl.bat "{b}"
Assemble ASM file (no COFF),\MASM32\BIN\Assmbl2.bat "{b}"
you can get your new menu item added on IDE restart.
You also need to copy bin\assmbl.bat
to bin\assmbl2.bat
and remove the /coff
from the latter.
Then you can compile fine from within the IDE with the new menu option.
Of course, you'll have to do the same thing for the link
and assemble/link
menu items as well. But, now that you know how it's done, that shouldn't present a problem.