Remember when calculator watches were the cool “thing” to have, back in the 80’s? Well, the first one was released in 1975 — called the “Calcron”. Click here for more pictures.

That wasn’t the only calculator watch released in 1975 though, as the Pulsar, with its shiny finish, followed right behind its heels. Next up, is the HP-01, released in 1977 at the hefty price of $650.

The oversized watch, sporting the widescreen LED, is the Sinclair, in which 10,000 were sold during its release in 1977. Lastly, we have the Hughes super-block calculator watch — named after its bulky metal case.

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