OBDI scan software

I have a 95 lumina with an intermittent miss, I do need to change plugs and wires so that may clear it up but I was thinking it would behoove me to have some sort of scanning device for this car and since I have several laptops gathering dust....

So where can I get/who makes software for scanning OBDI cars? Also does any of the known software(if there is any) do real-time scanning and display?


Thank You
Szlachta