Are we talking about the Singer 401? It has five black disks that sorta do embroidery stitches. I haven't used them on this machine yet. You have to maneuver the knobs in the front and I will have to look into the manual to refresh my memory. (It even came with a very clean manual) I saw a machine like it on eBay that claimed to have 10 disks. I don't know how accurate that is.
I am still trying to get organized. But I will soon.
I will start having to label my machines soon to tell them apart.