docs: function get_sector_list(sectors, start, fat_addrs, ssz, chkd) {
  	var buf = [], buf_chain = [];
  	if(!chkd) chkd = [];
  	var modulus = ssz - 1, j = 0, jj = 0;
  	for(j=start; j>=0;) {
  		chkd[j] = true;
  		buf[buf.length] = j;
  		buf_chain.push(sectors[j]);
  		var addr = fat_addrs[Math.floor(j*4/ssz)];
  		jj = ((j*4) & modulus);
  		if(ssz < 4 + jj) throw new Error("FAT boundary crossed: " + j + " 4 "+ssz);
  		if(!sectors[addr]) break;
  		j = __readInt32LE(sectors[addr], jj);
  	}
  	return {nodes: buf, data:__toBuffer([buf_chain])};
  }