HP-16C

The newest addition to the computing family here at the studio is a museum-quality specimen of the Hewlett Packard 16C Computer Scientist acquired through eBay.

Take a look at this great article titled "Long Live the HP-16C" by Valentin Albillo here.
Love this device! Of course, the HP Museum site has useful information about this and many other HP calculators. If seeking the missing manual, there is a scanned version here.

Also, Cameron Paine has a faithful simulation running on the Windows OS here. (Select the menu item View...Classic for the nostalgic visual replica.) Another version for the browser is meh.

Update 20150227:
One Voyager was not enough! We added a near-flawless HP-11C.

Additional internal data