I loved redpower but never got up to the computer stage. I am not ashamed to admit that I find them intimidating either. The strange thing is I understand the principle about remembering two values is not exactly difficult, but right now I am having way too much fun messing about in minecraft 1.5.2 so I am not planning on learning forth if/until I start playing redpower again. When I do get into mystcraft on my current game I think I will use something similar to Direwolf's method and it does have the advantage of being possible in 1.4.7 and 1.5.2+.
Ugh, I have to admit that I utterly despise RP2 computers. The language they use seems so obscure and nonsensical to me in comparison to Lua. I messed with them for about a few days one time in an effort to try and understand them, and I couldn't even get a simple program working. After many headaches and frustrations, I finally just ragequitted and vowed never to touch RP2 computers again. Haven't needed to either, as I've never come across something that an RP2 computer could do that a CC computer couldn't.