Changes

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.

Both are [[PC compatible RTC It 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 are programmed in the same wayBCD format modes.

#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)

#?? memory all other registers from #0E to #7F can be freely used as persistent memory

* 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.

The RTC of the SYMBiFACE II is supported by* [[FutureOS]] (binary and BCD mode)* , [[SymbOS]] (binary mode), [[HDCPM]].