[quote="davidjk"]i am playing the guitar and running it through some software on my pc .
the software excepts midi command.[/quote]
What program are you using on your PC?
And what connector do you want to use, i.e. USB, serial, parallel (or perhaps Bluetooth, or infrared?)
[quote="davidjk"]... rather than buy one i thought why not make one[/quote]
That's where the fun begins!

(and sometimes headaches

)