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    posted a message on Physical DECIMAL Calculator Currently Adding
    http://www.minecraftforum.net/topic/490990-subtractor/

    it uses binary inputs, but i'm sure you can modify that wit a binary-decimal converter

    i literally just finished it an hour ago :smile.gif:
    Posted in: Redstone Discussion and Mechanisms
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    posted a message on Torch Activated Circuit?
    Quote from huskrfreak88

    Thanks a lot for all the help everyone, I really appreciate the fast replies and everything! I can move forward with my project now!


    i hate to be a wet blanket, but wouldn't a TFF do the same thing, just with a button instead of a water fall on a torch....what i mean is: press out side button door opens, press inside button door closes. PLUS you get the added bonus of being able to reverse this process
    Posted in: Redstone Discussion and Mechanisms
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    posted a message on Subtractor
    Quote from MaudDib

    remember...its not the adder thats changed...your simply adding logic to the inputs and outputs of the adders to make it do what i described. its not as difficult as you think :wink.gif:


    i'll keep that in mind, thanks
    Posted in: Redstone Discussion and Mechanisms
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    posted a message on Subtractor
    ok here's the final product, it's a monster to say the least....



    if you notice any mistakes in my circuitry please let me know...primarily that 3 input or gate and the and gates leading into it
    Posted in: Redstone Discussion and Mechanisms
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    posted a message on Subtractor
    Quote from MaudDib

    in modern cpu design...the working motto is 'do more with less'. adders are so popular because its a matter of messing with the input values to make the adder 'subtract'..with little change.

    think about it: in math...a-b = a+(-:cool.gif:
    in binary logic: a - b = !(!a + :cool.gif:   ! meaning binary NOT, inverted bits.
    
    follow it in binary..assuming 4 bits for values from 0-15:
    
    to do 3-1
    
    3 = 0011
    1 = 0001
    !3 = 1100 = 12
    1100 + 0001 = 1101 = 13
    !13 = !1101 = 0010 = 2 <-- final result, which is what we wanted.

    most alu's (arithmetic logic units, primary component of a cpu) will have controls to let you invert an input value, and invert the output value and other little things, like zero an input (an inverted 0 input lets you do things like a=a+1). so most times, all you need is adders, and let the input circuitry handle fiddling the bits to get the result you want.

    heh i see you already posted the image...nicely done :wink.gif:


    thanks for the explanation :smile.gif:

    i just wrapped up a full subtractor and i'm going to post it in a bit, i'm not a huge fan of modified adders in minecraft and prefer dedicated logic gates

    any suggestions for making it smaller would be amazing....it's a monster to say the least lol
    Posted in: Redstone Discussion and Mechanisms
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    posted a message on Subtractor
    so adders are widely used in redstone design, why not subtractors? so if you have a subtractor design please post it here, if none are, i'm going to post mine in an hour and claim 1st :tongue.gif:

    EDIT: half subtractor



    there needs to be a repeater before/after that and gate, sorry
    Posted in: Redstone Discussion and Mechanisms
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    posted a message on What is a tick?
    which is why it was proposed that when referring to redstone ticks you use RT instead of just tick, to keep from confusion...
    Posted in: Redstone Discussion and Mechanisms
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    posted a message on Help with hidden stairs
    Quote from casp3r72

    As the title says,I have a problem with some hidden stairs.I tried to recreate this, and I got the pistons themselves to work but,I can't get the pressure plates to do anything.I was hoping someone could take my save and look at it and tell me what I did wrong.Any help is appreciated.
    Save-http://www.mediafire.com/?6uggedkvyw12a8k


    you links bother me, screenshots?
    Posted in: Redstone Discussion and Mechanisms
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    posted a message on Multible Switches to open one door?
    are you looking for a combo lock, or do you just want a bunch of nonspecific levers?
    Posted in: Redstone Discussion and Mechanisms
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    posted a message on Piston door with no showing pistons.
    Quote from DBish95

    no overhang either. sorry for being so picky but i need this


    ok i'm building it for you now, i'll have a working door in a bit

    EDIT: maybe not, this is more difficult than i thought
    Posted in: Redstone Discussion and Mechanisms
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    posted a message on My first Calculator
    it's pretty cool, try using adders, i made an alu that unlocks a door when you get a solution of 4 :tongue.gif:
    Posted in: Redstone Discussion and Mechanisms
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    posted a message on 2x2 piston gate
    Quote from grimper12341

    Mms jeb door has been made many times with no redstone showing, there's probs a vid around here somewhere, you can try a search (google search that is, forum search sucks)

    EDIT: Actually this is slightly different to the jeb door in that the first set of pistons are retracted into the floor and ceiling rather than the walls, but it's the same concept.


    i intentionally rotated it, i wanted to make a fallout style vault and this door reminded me of a vault door for some reason....
    Posted in: Redstone Discussion and Mechanisms
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    posted a message on 2x2 piston gate
    Quote from Cronofuge

    My only problem with it is the level of redstone that has to be shown, I know it's not currently covered so you can show us the wiring but judging by where the second button is there still will be a lot showing when it's covered.


    that second button can be moved as easily as the first, this is also very un-compacted so i can easily modify timing and add on to it. i also made it this way so people could easily see what is going on and modify the design for their purposes
    Posted in: Redstone Discussion and Mechanisms
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    posted a message on Awesome TNT/Redstone #2
    i noticed you had a lot of stairs at the beginning of that video....invest in an elevator > make a video for the elevator > actually do something worth seeing!
    Posted in: Redstone Discussion and Mechanisms
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    posted a message on Piston Subway
    personally i use a more compact but far less pretty system that relies on gravity to start the cart on powered rails
    Posted in: Redstone Discussion and Mechanisms
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