The Sinclair scientific, remade: A classic calculator was reverse engineered from the bare metal - [Hands on]
Stephen Cass · IEEE Spectrum · 2020
Was the Sinclair Scientific calculator elegant? It certainly was a hit, gracing the cover of publications like Popular Mechanic s after its release in 1974. Cleverly written firmware dragooned its limited processor, intended only for basic arithmetic, into performing way beyond specifications. This allowed Sinclair to sell a scientific calculator to countless folks who otherwise could not have afforded one. But it was also slow and sometimes inaccurate, provided barely enough mathematical functions to qualify as a scientific calculator, and was difficult for the uninitiated to use.