The SmartWatch consists out of the [[RTC]] itself and an EPROM expansion with a lot of RSX commands. The RTC itself was inserted like an EPROM in any kind of ROM or EPROM card. Further it contains a little battery. At least one clock is still running in 2014!
The Time-ROM can be on another ROM-select than the SmartWatch. [https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/real-time-clock-board/msg249697/#msg249697 Source].[[SymbOS]] is searching for the TIME.SET RSX command. It will then use this ROM. [https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/real-time-clock-board/msg249768/#msg249768 Source].
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