I've been bored lately, and I have decided to try to build a 1 byte RAM unit using capacitors. I plan to make a reader for 3x5 cards that would detect which of 8 "cells" on the card were blacked out and store that data in the RAM unit. Eventually, I plan to build a logic circut or program a microcontroller that would let the output from the cards be displayed on a LCD. I have the RAM unit planned out as well as the card reader (a light on the bottom and switches that only allow current to flow if there is no light- can't remember their name right now). The switches would turn each cell in the RAM unit "on". My only problem is that I don't know how to keep the switch in the RAM "on" even after the reader has been turned off. I need to scan some schematics and post a link to them, so any help would be appreciated.