I'm also developing a bit of an interest in tinkering with assembly these days. 16-bit MASM should work fine under DOSBox - see here: http://www.prashanthpai.com/blog/run-masm-808 … 4-using-dosbox/

Haven't tried this, but you should be able to generate 16-bit code using a 32-bit version of MASM (i.e. Windows), so you might be able to get away with assembling outside of DOSBox then testing in DOSBox itself, for speed and convenience.

hardware emulation in DOSBox isn't 100% accurate - for one thing, CPU emulation isn't cycle-exact, so you might want to take that into account when it comes to instruction timings and low-level optimizations. Others here could be more helpful about specific limitations.

The normal reply is that dosbox is not made for 100% accuracy. So when you program and especially compile in Dosbox, little errors might creep in your binaries. So beware...

Thank's. I will try and see... If it doesn't work as expected, i'll try with FreeDos or VM's running MS-DOS.

.-083 wrote:

or VM's running MS-DOS.

I'd recommend against that, as DOSBox emulates more hardware and does so more accurately than a typical VM. You'd be better off booting MS-DOS within DOSBox.

VMs might be more true to cpu emulation. AFAIK the best would be to use bochs for something like that

What kind of cpu does Bochs emulate? And Dosbox? I mean, how can i know the exactly hardware where i'm running DOS ? 386, AMD K7, etc...

You will need to look it up for Bochs, as for Dosbox, I'm sure it emulates intel but not a definite set, I think.

This: http://bochs.sourceforge.net/techdata.html
Makes me think i can programme for 8086 normally 😁
Thanks.

if you're not doing any tricks like using undocumented instructions or intentionally triggering faults, then DOSBox is fine for assembler work.
I use TASM under DOSBox to build my patches, no problem there.
However, if you need really accurate CPU behaviour then Bochs is the more appropriate choice. Note that even Bochs doesn't support really old hardware behaviour like the value of sp on the stack after a push sp, or transferring control using pop cs.

Great. And you 're working with dosbox "as-is" or with a MS-DOS install?
I 'm using the DosBox HAL9000's build with ms-dos 6.22.

I'm using DOSBox "as-is".