This is a modified version of your draw
function which preloads all images before putting them on a canvas.
It assumes you have a canvas with id 'anim' (as there is no reference of the canvas in the source you provided)
<canvas id='anim' width='660' height='500'></canvas>
JavaScript: (tested on an iPad)
function draw() {
var ctx = document.getElementById('anim').getContext("2d");
var start = 1, stop = 121,cur=start,imgArr=[];
var loadLoop = function() {
var img = document.createElement("img");
img.onload = function() {
imgArr.push(this);
cur++;
if(cur > stop) {
// all images preloaded
animate();
}
else {
loadLoop();
}
}
img.src = "jpg_80/t5_"+(cur)+".jpg";
}
loadLoop();
function animate() {
var timer = setInterval(function() {
ctx.drawImage(imgArr.shift(), 0, 0 );
if(imgArr.length == 0) {
// no more frames
clearInterval(timer);
}
},1000/24);
}
}