The real problem is that you can't just resize a 320 x 240 image to 240 x 320. You'd end up with a goofy looking oval countdown. Beyond that, PhotoShop is a great photo editor, but I find it to be clumsy at best for editing animations.
On the MX-980 screen, a significant portion of the screen goes unused for a countdown. With a little creative editing, you can get a countdown to appear as though it's a full-screen animation, but still run at full speed.
Here's a sample of what you can make by compositing two images. Note that topmost animation
this is just a sample, and will run slow as molasses on the actual MX-980:
Note: My sample here is actually running a bit fast, but after I posted it, I got lazy and didn't want to go back and slow it down. On the remote, the process below results in an animation that runs very close to one sweep per second.
To create the same visual effect on the MX-980, you separate the parts of the image that actually change from the parts that stay the same. This GREATLY reduces the file size, because the only way to make animations run at full speed on the MX-980 is to save them with no inter-frame compression.
So, to put the animation on the 980, take this background and place it as an image at the back of the page:
Then, take this animated GIF and center it on the background (which is pretty easy, since the whole thing is one big alignment marker):
Next, be sure to set your GIF animation setting to "Animate Once."
There you go! Easy as pie!
(And yes, if you want this version, feel free to right click and save the target files to your own computer.)