SYMBiFACE II uses a Dallas DS12887A RTC chip. [https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/real-time-clock-board/msg249380/#msg249380 Source]
According to This chip is a modernized version of the datasheetMC146818, this has 14 bytes of registers and 114 bytes of batterythe original RTC chip used in the IBM PC/AT. It includes a built-backed static RAMin battery and crystal. It's ram inside is a [[PC compatible RTC chip]] and is programmed in the device. Century register doesn't exist on this particular modelsame way.
It is a [[PC compatible RTC has 14 bytes of registers and 114 bytes of battery-backed static RAM. Century register doesn't exist on this particular model. The chip]] also provides time-of-day alarm, three maskable interrupts with a common interrupt output, and a programmable square wave output. It has hardcoded daylight saving adjustment, 24-hour and 12-hour format modes, binary and is programmed in the same wayBCD format modes.
== Ports ==
<pre>
Number Content Values
#00 actual second 00-59 (bcd or binary)#01 alarm second 00-59 (bcd or binary)#02 actual minute 00-59 (bcd or binary)#03 alarm minute 00-59 (bcd or binary)#04 actual hour 00-23 (bcd or binary)#05 alarm hour 00-23 (bcd or binary)#06 day of the week ??01-07#07 day of the month 01-31 (bcd or binary)#08 month 01-12 (bcd or binary)#09 year 00-99 (bcd or binary)
#0A status A see below
#0B status B see below
#?? memory all other registers from #0E to #7F can be freely used as persistent memory
</pre>
* Note: Register B, Bit 2 allows to select BCD or Binary mode for registers 0..9 * Whether RAM locations are reserved for whatever purpose (like info about connected 40/80 track drives) is unknown. See note 1 please.
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+.
== Software ==
The RTC of the SYMBiFACE II is supported by [[FutureOS]] and , [[SymbOS]], [[HDCPM]].
== See also ==