This takes me back! Your project is similar to work I've done in the past, also in MS-DOS and also using Turbo C, that used a computer's joystick port and SoundBlaster card. So I'm familiar with the tools and concepts involved.
A little more recently I contributed work to an Ethernet-card driver for the classic MacOS platform, which used memory-mapped I/O but was otherwise similar.
I have fifteen years' experience as a software developer, much of it working in C, and I'll be able to deliver you high-quality code within a short timeframe. I am also a native English speaker.
I'm still relatively new to Freelancer.com and would be delighted to have the opportunity to show you what I can do.
Simon