One of the biggest complaints I get is the text screen is too small. I generally agree. More recent computers actually have the ability to use a higher resolution, but do not take advantage of it in the default mode. This instructable is for more advanced users. Please get help before starting this project if you are at least the little bit unsure.
You will need to have the documentation for both your video card and for your monitor. You will see numbers like 640x48 800x600 1024x768. Take those numbers and use the lower of the two from the video card and the monitor settings. If you can only use 640x400 then stop here. The 640x400 is the default. there is a 320x200, but I have not see that in years,
In my case the highest resolution for the monitor was 800x600. Still a boost over the default 640x400 screen.
Lastly you need to find out what your Linux system uses to boot, Lilo (we will not cover it), Grub (aka Grub1) or Grub 2.
For our purposes we will be using Grub2 for the images. Pictures in this step are the original screen shots.