Casio fx-451

Back in the 80’s, the coolest calculator you could have was the Casio fx-451. The updated version of the 411, the 451 included functions for trig, hex / oct / bin, stats, and even simple conversions.The left half was a conventional-looking, solar-powered calculator, embedded in a folio case. Connected via a ribbon cable via the spine of the case, the right half of the folio was a membrane keyboard, used to access many of the extended functions.