Enlarges ascii art.

main.js

string = document.getElementById('input').value;

/*
First string is the 'index', with escaped characters for each substitution, in order. First character = first array, second character = second array, etc.
Each array is of the format ['abc','def','ghi'], which maps to 
    abc
    def
    ghi
in the output.
*/

var substitutions = [
  " /\\_-'",
  ['   ', '   ', '   '],
  ['/  ', ' / ', '  /'],
  ['  \\', ' \\ ', '\\  '],
  ['___', '   ', '   '],
  ['   ', '---', '   '],
  ['   ', '"\\ ', '\\  ']
];

substitutions = substitutions.map(x => ((typeof x) !== "string") ? [x[2], x[1], x[0]] : x)

document.getElementById('output').innerHTML = '<pre>' + string.split('\n')
  .map(row => row.split('')
    .map(char => substitutions[substitutions[0].indexOf(char)]))
  .map(oldRow => oldRow.map(charSet => charSet ? charSet[0] : [])
    .join('') + '\n' + oldRow.map(charSet => charSet ? charSet[1] : [])
    .join('') + '\n' + oldRow.map(charSet => charSet ? charSet[2] : [])
    .join(''))
  .join('\n') + '</pre>';