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#author("2024-06-09T19:04:34+01:00","default:admin","admin")
-Produced from April 1975
-CMOS IC made by Hitachi
-White ceramic circuit, often marked "5" or "AB5"
-Novel dual stator rotor
-9 Jewels
-Battery 392

From [[thewatchforum.co.uk>http://thewatchforum.co.uk/index.php?/topic/95876-japanese-giant-goes-missing-ricoh-watches]]

 The cal570 was eventually replaced by the smaller and cheaper cal590. However, compared to competitors offerings the watches were still often housed in relatively expensive casings and carried premium prices. Watches with this movement date from 1976 to perhaps 1978.

http://blog.livedoor.jp/cal_4402/archives/7318716.html

https://www.jstage.jst.go.jp/article/tokeieafj/79/0/79_KJ00001681354/_pdf/-char/ja

*CMOS IC [#v185d177]
Made by Hitachi, with date code, IC with 10 connections, silicon die marked "TD4115", ceramic package with metal top.
Made by Hitachi, with date code [see [[510]] ], IC with 10 connections, silicon die marked "TD4115", ceramic package with metal top.

*590A [#nb829461]
Slight variation with less attractive brown circuit

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