I still have a three-vertical-button Alto mouse that somehow ended up in a box of my stuff when I left PARC. I had assumed it had yellowed with age but it's the same color as the one in that picture. Perhaps that picture is recent and the same yellowing happened. There were also some with the three buttons arranged top-bottom but I think everyone figured out quickly that they were hard to use.<p>I never used that chord keyboard (note that it <i>hasn't</i> yellowed).<p>I still have some old custom D machine microcode lying around although I suspect the media are now unreadable. Sigh.