== PC compatible RTC chip ===== Usage in CPCs ===
Usage in [[SYMBiFACE II:Realtime clock]]:
Usage in [[Aleste 520EX - I/O Ports]]:
Uses a russian KR512WI1 chip (which is, according to the Aleste's
Manual) compatible to western MC146818 chips. Connects to a 32.768kHz crystal. Connects to the PPI. : PPI Port A.Bit0-7 =Data bus PPI Port C.Bit0 = Read/Write (0=Write, 1=Read) PPI Port C.Bit1 =ControlIndex Access (0=No, 1=Access) PPI Port C.Bit2 = Data Access (0=No, 1=Access)
In the Aleste's Ext Port, the RTC must be enabled, and PSG and
8253 must be disabled.
Unknown if century is supported.
=== RTC Registers ===
00h Second (00..59) ;\
32h battery backed RAM (commonly used as Century) (19..99) (see notes)
=== Century Notes ===
First of, whether or not the Century is stored at [32h] depends on software. PCs are conventionally using it like so. SYMBiFACE II seems to (try to) do the same. Whether the Aleste and Dk'tronics do store the century is unknown - and, if they should do, it might be anywhere at [32h] or elsewhere, in BCD or in binary... or even octal or ascii.
The DSE feature is crap, and should be disabled (it's using a hardcoded timezone, and thus works only in a few countries, and, it lacks a flag that indicates if daylight saving time is active or not).
SYMBiFACE II Cautions: Incorrectly claims to have 128 bytes battery backed RAM (but actually uses a DSDS1287A DS1287A chip with 50 bytes battery backed RAM) (128 byte chips don't exist anyways, the maximum would be 114 bytes). Thecentury is accidently referred to as milleniummillennium, it seems to be stored as BINARY value 19 or 20 (which may conflict with the Y2K-panic chips which are only "optimized" for destroying BCD values). == Other chips ==* [[ACU Real Time Clock (DIY)]]* [[Dobbertin Smart Watch]]* [[URTC-8 Universal RTC for Z80 computers]]* [[Nova]] (M48T35Y-70MH1F chip) [[Category:Datasheet]]