Graphing Calculator in Turbo C (MS DOS)

This is a Graphing Calculator I made many years ago (I think back in 2003). It was the first time I got introduced to programming in Turbo C. Initially I used my programming skills (Turbo C) for solving Mathematical Problems. This program is a very simple graphical calculator, that you can use to draw sin, cos, Tan curves. Its very amatuerish (thats what I feel now), but, back then, when I created it I thought it was quite cool :S (silly me!).

Note: It runs only in MS DOS Mode and in 256bit color.

Here's a screenshot of the program drawing a sin curve: