I couldn’t resist setting this up for my next Digital Machinist column on logarithmic scales:
The caption will read “Photo 1: A replica Tektronix Circuit Computer shown with its natural enemy, an HP 50g Graphing Calculator.”
It’s my desk calculator. In the Basement Laboratory, I use the HP 48 calculator app, with a couple of $10 Sharp calculators in harm’s way.
The Smell of Molten Projects in the Morning 
Very nicely done, look forward to the digital machinist blurbage. I am a real fan of the Alvin Screw Selector- always at arm’s length. A sliding card with a bunch of little windows. (Amazon still sells them for $15). Carry on.
A similar and ancient Universal Reference Calculator from TAD Technical Services sits by the monitor. Because it has hard inch sizes all the way, it sees very little shop light nowadays.
But it has C and D scales along one edge: it’s a slide rule!