Seiko C359-5000

Seiko C359-5000

The 1970s were coming to an end when Seiko released the C359, their second calculator watch, in a range of different cases and bracelets.

You could get it in gold or stainless, white crystal or black, and even with variations of the case shape too. A range of options was obviously a winner for Seiko because they did it with a significant number of their watches, from memory there’s about 10 variations of the G757!

This is my favourite of the range – the C359-5000 with black crystal and CA090 bracelet. Looks good, feels good on and with a load of functionality as long as you have a stylus handy.

Unlike Casio’s finger-touch calculator watches that were still a year away, Seiko (and Citizen) preferred to keep a small form factor and require the user to have something pointy to press the calculator keys with.

c359The downside to this was slippage and overpressing; slip with your stylus and you scratch the keypad which really detracts from the look of the watch. Press the buttons too hard and you run the risk of them getting wedged inside the case and you (or a watchmaker) would have to pull the watch apart to fix it.

But for someone who wanted a ‘normal’ size watch, with a calculator function, the C359 was perfect.

Other functions were a light, 12-hour time, day and date, daily alarm and hourly time signal. You could light all the segments in the LCD to test them by advancing to set mode then pressing both right-hand buttons too.

The calculator was the basic 8-digit version that was a staple of the 1970s and 1980s. There were the four main functions, a decimal point and percentage button and that’s it. But, then again, what else would you need…?

Still relatively abundant today, the C359 has stood the test of time and is still a classy watch. The only problem with them is the battery cover. As the rubber gasket perishes over time, the battery cover either becomes locked on, or the opposite happens and it falls off. You will always find at least one of these on eBay being sold without a battery cover.

Fortunately for those with the locked-on battery cover, there is help at hand too. Like many of Seiko’s early digitals the case can be entirely separated courtesy of some spring pins in the top and bottom of the case. Once you’ve worked out how to open the module, removing a stuck battery cover becomes much easier -assuming, of course, the previous owner didn’t leave a battery in it which has now leaked throughout the internals rendering it useless!

If you like early Seikos, LCD watches, or calculator watches, keep an eye out for this one. You won’t regret buying one.

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4 Responses to Seiko C359-5000

  1. Hey, so how did you mange to get the locked-on battery cover off or how did you remove the whole back?

    Many thanks

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