You shouldn't have to scroll the entire screen, blitz should be able to draw lines with the text fast enough and then you can just make a system of lines moving up and as the top line moves outside the screen area; move it down to the bottom and give it a new line of text to draw. I have used something like that a number of times and it seems fast enough.
Otherwise if you want to scroll the entire screen then make a buffer that is as big as the screen plus one row extra on the bottom. Draw the current line into that row that is out of sight and each frame use copyrect/block to scroll the entire buffer and once you have scrolled enough draw a new line on the bottom.
I hope the above made sence ;-)
Otherwise if you want to scroll the entire screen then make a buffer that is as big as the screen plus one row extra on the bottom. Draw the current line into that row that is out of sight and each frame use copyrect/block to scroll the entire buffer and once you have scrolled enough draw a new line on the bottom.
I hope the above made sence ;-)