I found this today, I myself started out doing much the same as he, pretty basic but at least he went to the effort of building basic DAC's.

This will never replace real scanners, but it's an interesting and fun way to experiment and learn. I know most of you here are light years ahead of this stuff, but you might find it interesting or in the very least sentimental.

Lasers for amateurs http://members.aol.com/pissavin/index.htm