// Generated by CoffeeScript 1.9.2
var Buffer, create;

Buffer = require('buffer').Buffer;

create = require('./create');

module.exports = create('xmodem', function(buf, previous) {
  var code, count, crc, i;
  if (!Buffer.isBuffer(buf)) {
    buf = Buffer(buf);
  }
  crc = previous != null ? ~~previous : 0x0;
  count = buf.length;
  i = 0;
  while (count > 0) {
    code = crc >>> 8 & 0xFF;
    code ^= buf[i++] & 0xFF;
    code ^= code >>> 4;
    crc = crc << 8 & 0xFFFF;
    crc ^= code;
    code = code << 5 & 0xFFFF;
    crc ^= code;
    code = code << 7 & 0xFFFF;
    crc ^= code;
    count--;
  }
  return crc;
});