Changes
/* Bugs */
This is the documentation about the '''realtime clock''' of the [[SYMBiFACE II]] expansion card.
== Ports ==
#0C status C see below
#0D status D see below
#32 millenium millennium 19 or 20 (bcd or binary)
#?? memory all other registers can be freely used as persistent memory
</pre>
== Bugs ==
* Register 32h is meant to contain the Century (not MilleniumMillennium)
* Register 32h can be only '''either''' bcd '''or''' binary (not both)
* Register 32h documentation does not specify whether it shall be BCD or Binary
* Register 32h source code supports only two centuries (19 and 20) this is probably due to misunderstanding the RTC chip datasheet (which sorts of suggests the 8bit RAM location can contain only two different values, which is total nonsense)
* Whether other RAM locations are reserved for whatever purpose (like info about connected 40/80 track drives) is unknown. See note 1 please.
* The RAM capacity is 50 bytes: register 0Eh..3Fh (although SYMBiFACE II is incorrectly advertised to have 128 byte persistent RAM)
Note 1: In the discmag [[Future View IV]] a proposal is given how to use the non volatile RAM of the SYMBiFACE II and the CPC-Booster+.
== Status registers ==
bit7 0 = battery is nearly empty, please charge or replace
</pre>
== Software ==
The RTC of the SYMBiFACE II is supported by
* [[FutureOS]] (binary and BCD mode)
* [[SymbOS]] (binary mode)
== See also ==
* [[Programming:SYMBiFACE_II|SYMBiFACE II documentations]]
[[Category:FutureOS]]
[[Category:Hardware]]
[[Category:Peripherals]]
[[Category:Programming]]
