This is the documentation about the '''realtime clock''' of the [[SYMBiFACE II]] expansion card.
My (arnoldemu's) symbiface 2 SYMBiFACE II uses a Dallas DS12887A. Documents claim this has 128 bytes RAM. Century register doesn't exist. It's ram inside the device.
The picture from the Symbos website shows a DS1287A. This has 50 bytes RAM. Century register doesn't exist.