Yes, you do need a bit of JavaScript to accomplish this!
The HTML inside the <body> first sets up two <div> element for the two animations, and then defines two "instances" of HAniS for the animations, followed by the JavaScript functions needed to connect the two animations::
<div id="handiv" style="display:inline-block;width:500px;"> </div>
<div id="handiv22" style="display:inline-block;width:500px;"> </div>
<script>
var b = new HAniSF();
var a = new HAniSF();
function aready() {
a.frameChanged(changb);
}
function changb(frm) {
b.showFrame(frm);
}
function init() {
a.setup('hanist1.txt','handiv', aready )
b.setup('filenames = TIR1.GIF, TIR2.GIF, TIR3.GIF \n imagecan_style=border-radius:30px; \n start_looping=false \n' +
'overlay_nonewdiv=t \n overlay_filenames=TMAP.GIF \n controls = zoom, overlay \n' +
' overlay_labels=Map \n buttons_style = flex:auto;margin:2px;' ,
'handiv22');
}
window.onload = init();
</script>
(Note also in the 2nd instance, the overlay_filename need only be
given once, since it applies to all frames.)