Scrolling Smoothly through Large Scripts

[Ray]

Seasons Greetings on Christmas Eve!

Does anybody know how to scroll just one line per mouse-wheel movement 
through the script editor window?

I typically view several thousand lines at a time.  Each push of the 
little scroll wheel on my mouse produces an abrupt 'jerk' of 10 or 15 
lines.  It's really hard on the eyes by the end of the day.

Ideally scrolling would be totally smooth without even jerking one line 
at a time, but one line at a time is better than a random group at a 
time causing me to re-orient myself.

Many thanks!