Simple midi setup DS61 to iMac 2013

[Wackienne]

I've used my Juno for performance for years, but now I'd like to build some music on my iMac, using the keyboard, Audacitym and a simple Midi setup. The problem is I can't get the Juno talking to the computer.

I've followed the directions about downloading a driver, but as soon as I connect a cable from the USB-A port on the Juno to the same on the mac, I get an error message that won't go away, even if I turn the Juno off or disconnect the AC. The only thing that makes it disappear is pulling out the USB cord. The message says, "Battery low. The batteries have run low. Please replace the batteries or use an AC adaptor”. Well, it's running on AC, so...

Am I using the wrong cable? Do I need an interface? I do have one, but it's ancient and I can't find it online to update it.

I'm really in a fog, and any help would be appreciated. But speak to me as to a five-year-old child, because I have very little experience with this end of things.

Judy