DOS Compatable OS

[Scott Stevens]

On Wed, 14 Dec 2005 15:43:06 -0500
Gary Sparkes <mokuba at gmail.com> wrote:

> I'm rather bored, so I thought I might try and hack together a
> small project OS compatable with at least DOS 1.x or similar, is
> there any decent resource for information on dos compatability
> and how to achieve it, or is it left as a reverse engineering
> exercise for 'the reader' ? :)
> 
> 

The PC-DOS 1.0 Reference manual has all the system calls included
in it.  That material was split out to the DOS Technical Reference
for later versions.

For 'compatability' purposes, just code to the system calls and
resist the temptation to do an end-run to BIOS routines for
efficiency's sake.