On October 2, 1968, a mouse device named Rollkugel (German for "rolling ball") was described as an optional device for its SIG-100 terminal was developed by the German company Telefunken.
1968 年 10 月 2 日，德国 Telefunken 公司开发了一种叫做 Rollkugel （德语中“滚动球”的意思）的鼠标设备，据该公司描述，Rollkugel 是作为其终端 SIG-100 的可选设备而开发的。