Almost any program you are likely to get will do what you want from a midi keyboard, but unless you are VERY good at holding your tempo the score will look like a bunch of maggots have been crawling around on it.

One problem, for most of us ordinary musicians is that you must hold a key for the full note value, otherwise you get dotted/tied/interrupted notes with little bitty random rests filling in until the next note starts. About the only people I've met (face-to-face) who can do a decent job in this respect, are trained organists, who have learned to hold the key to full sustain.

A technique I have used is to set a note duration as though making stepwise input, and just play the tune in, for example, in all eighth notes. A quarter note is two, and you actually "play" both notes. A half not is four eighths, etc.
With the note duration set, you get rid of all of the random-length notes and rests, and it's a lot easier to go back through and "merge" the sustained notes than it is to clean up my bad rythms.
The "merge" can be done by just applying a "tie" to link the notes, although if you're going to print it, you would want to put full-value notes in.

John