full adder (and n-bit adder!)

some modelling with circuit gates in calculang

The full adder below adds 3 binary inputs (A_in, B_in, C_in) and produces 2 binary outputs: sum and carry. It is made using modular calculang.

Multiple adders can be combined to perform more complicated addition.

The logical components are the same logical components that combine to produce a CPU and a computer.

Whacky idea 🤯

Is it possible to simulate a computer in calculang? Would it be useful? Would it be hard? (tbc)

Computers have been simulated in whackier ways.

model output

vega_interactive(viz)

viz = calcuvizspec({
  models: [full],
  input_cursors: [{}],
  mark: 'text',
  encodings: {
    x: {'name': 'A_in', type:'nominal', domain: [0,1]},
    y: {'name': 'B_in', type:'nominal', domain: [0,1]},
    column: {'name': 'C_in', domain: [0,1]},
    text: {'name': 'value', type:'quantitative'},
    row: {'name': 'formula', domain: ['sum','carry']},
    color: {'name': 'value', type:'nominal'}
  },
  width: 100, height:100,
  spec_post_process: spec => { spec.config = {legend: { disable: true}}; return spec}
})

DOM.download(serialize(viz.datasets.data), "data", "csv download")

calculang source

on GitLab

full-adder.cul.js

import { XOR, AND, OR } from "./gates.cul.js";

export const A = () => A_in;
export const B = () => B_in;
export const C = () => C_in; // carry in

export const sum = () => XOR({ A_in: XOR(), B_in: C() });

export const carry = () =>
  OR({ A_in: AND(), B_in: AND({ A_in: XOR(), B_in: C() }) });

gates.cul.js

// soon: rewrite on NAND logic

export const A = () => A_in;
export const B = () => B_in;

export const AND = () => A() && B();

export const NAND = () => !AND(); // not and

export const OR = () => A() || B();

export const XOR = () => {
  // exclusive or
  if (AND()) return 0;
  else return OR();
};

n-bit adder

I need to do some bit re-ordering stuff and split into a separate notebook.

viewof A_string_in = Inputs.text({value: "000"})
viewof B_string_in = Inputs.text({value: "111"})

vega_interactive(
  calcuvizspec({
    models: [n_bit_adder],
    input_cursors: [{A_string_in, B_string_in}],
    mark: 'text',
    encodings: {
      //x: {'name': 'A_in', type:'nominal', domain: [0,1]},
      //y: {'name': 'B_in', type:'nominal', domain: [0,1]},
      x: {'name': 'bit_in', domain: _.range(0,A_string_in.length,1)},
      text: {'name': 'value', type:'quantitative'},
      y: {'name': 'formula', domain: ['sum','carry','A_bit','B_bit']},
      color: {'name': 'value', type:'nominal'}
    },
    width: 100, height:100,
    spec_post_process: spec => { spec.config = {legend: { disable: true}}; return spec}
}))

appendix

import {calcuvizspec} from "@declann/little-calcu-helpers"

//import { aq, op } from '@uwdata/arquero'


vega_interactive = { // credit to Mike Bostock (starting point): https://observablehq.com/@mbostock/hello-vega-embed
  const v = window.vega = await require("vega");
  const vl = window.vl = await require("vega-lite");
  const ve = await require("vega-embed");
  async function vega(spec, options) {
    const div = document.createElement("div");
        div.setAttribute('id','chart-out');
    div.value = (await ve(div, spec, options)).view;
    div.value.addEventListener('mousemove', (event, item) => {
      //console.log(item);
      if (item != undefined && item.datum != undefined && item.datum.formula != undefined) {
              /*DN off viewof formula_select.value = item.datum.formula;
      viewof formula_select.dispatchEvent(new CustomEvent("input"))
*/
      }
    })
    div.value.addEventListener('click', (event, item) => {
      console.log(item.datum);
      
    }) // DN
    return div;
  }
  vega.changeset = v.changeset;
  return vega;
}

full = require('../../models/adders/full-adder.js');

n_bit_adder = require('../../models/adders/n-bit-adder.js');

full

n_bit_adder

json2csv = require("json2csv@5.0.7/dist/json2csv.umd.js")

// thx to https://observablehq.com/@palewire/saving-csv
// Ben Welsh and comments from Christophe Yamahata
function serialize (data) {
 let parser = new json2csv.Parser();
 let csv = parser.parse(data);
 return new Blob([csv], {type: "text/csv"}) 
}

function serializeJSON (data) {
 return new Blob([JSON.stringify(data,null,2)], {type: "text/json"}) 
}