• Research : Mind Blown

    Dylan Brophy01/28/2018 at 20:42 4 comments

    I was going to make an ALU with my adder, my XOR/AND logic card (which I was still working on), and a ton of other relay-consuming parts.  Then I did some research on how best to wire all these parts together and found a 1-bit, 9-relay, 128-function ALU.

    Although many of these functions are useless or unknown, a 8-bit version would be many times more powerful than my ALU design, and probably use less than half of the relays.

    Created by Dieter Mueller

    For full details look here.

    I decided to build the circuit.

    0 NOR 0 is 1.
    0 NOR 1 is 0
    1 + 0 = 1

    Seems to work!

    The eight switches tell the ALU which function to run.  The two small switches on the right side of the breadboard are A and B inputs.  Red LED is the result, small green LED in the left is the carry out.

  • Relay Adder

    Dylan Brophy01/27/2018 at 02:11 0 comments

    I have built a relay adder before on a breadboard.  It was a two bit adder just to play with my new relays.

    I decided to make a more advanced, more permanent version.

    The new one uses 8 relays: 2 for the first bit and 3 for each bit after.  There are LEDs soldered in for the result and the carry bit from the sum of the least significant bits.

    Was still working on the third stage. Third red LED wasn't in yet.

    I decided not to use switches because I want to possibly use it in an ALU later on.  The port on it is there to connect to some kind of ALU backplane.

    I tested it by adding two and three.  Since I didn't want to put switches in the test I wired the inputs of the adder directly to the power rails for two + three:

    There is an LED in the middle of those really bright ones. 101 -> 5 = 2+3

    The wiring of the board is a bit crazy, but each stage is a bit better. The third stage has only two floating wires! XD

    Next i think I'll work on an XOR/AND board.