I didn't know this until I acquired some of these, but the keyboards have a mouse port on the back; it looks like a standard serial 9-pin connector and it has "MOUSE" labelled above it. However, I have yet to find any documentation on the pinout or electrical/comm specifications for the mouse. Does anyone recall having a mouse hooked up to their Tektronix 4105/4205 and what kind of connection it had? -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://www.xmission.com/~legalize/book/download/index.html> Legalize Adulthood! <http://blogs.xmission.com/legalize/>