increase max. console output lines

Hi,

I have a lengthy R script, which just got a bit too long for the console 
output to cache all executions history, i.e. when scrolling to the top 
the first few commands executed are not listed any more.
What is the current limit (characters? lines?) and how do I increase it?

R is 2.14, Win7, 64-bit if that matters.

thanks, Thomas