First of all, from top, to bottom.
CobaltKobold
it's a intresting idea, but the problem about not using liquids, is that you have to tell the dwarfs manualy to 'Refill' the 'Screen', and thus would not be a computer, beacuse for it to work it needs your intervention. Liquids are different beacuse a computer can control liquids via the use of floodgates etc. To control your idea we have some problems.
1 as stated above manual refiling, which is controled by the player. It has to be controled by the computer
2 Sencing what rock is were. This is simply impossible at the moment, pressure plates don't work here beacuse a rock is a item. The only way for it to work would require either manual piting (not automatic therefore NOT a computer) or a lever in conjuction with a hatch, which again is manual, as a lever cannot be driven by computer, even then you would still manually need to refil piles
Techhead
For point 1 what your describing is a programm in conjunction with a computer, all you need to do is make a programm that does it
For point 2 are you sugesting some kind of rainbow effect controled by a program? Please elaborate.
duro
Nil is not is not a word in memory its is part of a 3 state machine ( the turing machine) why we have to use 3 states? Nil means in any turing machine that the state of the 'cell' (our 'memory') has not ever been writen on. This is important for the Turring machine to know, beacuse the only manipulative action it can take is to write to the cell, imagine trying to erase a cell that was always '0' then you'd be comming up with false data entrys of '1' without it this would be clased under the machine as never used, so you have to have a nil or risk huge errors.