🚀 go-pugleaf

What operating system are you running under? What compiler are you hoping 
to use? If you are hoping to support such a wide range of devices you 
will have substantial problems (I speak from experience here) and under 
DOS may find it most practical to hook INT 24H- if you refer to 
appropriate technical info you will find that there is a technique to 
return straight to the application with an error code. I can warn you 
however, that you will be getting into _very_ deep water here- the code 
is not at all simple, cannot be expressed in a high-level language (i.e. 
you will need inline assembler and an intimate (I'm tempted to say 
gynaecological) knowledge of the stack state) and may vary depending on 
the memory model in use, and I admit freely that I do not know what would 
happen if you attempted to run under Windows 3.x, Windows '95, Windows 
NT, OS/2, or a DOS emulator such as DOS Merge.

You may find it easier to educate your users. :-)

Mark Morgan Lloyd
mark_tbu@cix.compulink.co.uk

[Opinions above are the author's, not those of his employers or 
colleagues]