see ya later, calculator

We've spent most of the day clearing out the loft.  I found these three hidden away in a box of .... stuff.

The Sinclair dates from 1974 and the Texas Instruments SR-51A dates from about 1975.  I bought the TI calculator when I had to do really big sums.  

The third one, the Casio - I have no idea about.  Didn't even know I had it.  But - it still works.  It's solar powered (or ambient light powered) and too useful to remain hidden in the dark.  I shall find a use for it (apart from a blip, that is.)

As for the other two - I'm not sure what to do with them.  Is there a home for old calculators somewhere?