Changes

The SmartWatch consists out of the [[RTC ]] itself and an EPROM expansion with a lot of RSX commendscommands. The RTC itself was inserted like an EPROM in any kind of ROM or EPROM card. Further it contains a little battery. At least one clock is still running in 2014! The Time-ROM can be on another ROM-select than the SmartWatch [https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/real-time-clock-board/msg249697/#msg249697 Source].[[SymbOS]] is searching for the TIME.SET RSX command. It will then use this ROM [https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/real-time-clock-board/msg249768/#msg249768 Source]. <br>

The 28pin '''SmartWatch''' (DS1216) is an adapter that can inserted in standard ROM sockets, a ROM chip can be mounted on the adapter, finally, inside of the adapter is a 16pin '''Phantom Time Chip''' (DS1315). Normal memory reads are forwarded to the piggyback ROM. After reading from a specific sequence of addresses, the ROM is disabled, and data is instead read from the Phantom Chip via 1bit databus. Writing to the Phantom Chip is done by '''reading ''' from a specific sequence of addresses, too.

The RTC chip requires 64 sequential writes with magic serial data on A0 to unlock it, immediately followed by 64 sequential reads to retrieve the 64-bit time data packet from D0, after which the chip locks itself back into ROM mode. <br> === Register 0..7 Real-Time Clock Registers === 0 1/100 Seconds {| class="wikitable" style="text-align:center;"|-! rowspan="2" | Register !! colspan="8" | Bit Position !! rowspan="2" | Range (BCD 00h..99h) |-! 7 !! 6 !! 5 !! 4 !! 3 !! 2 !! 1 Seconds (BCD 00h!! 0|-! 0| colspan="4" | 0.1 SEC || colspan="4" | 0.59h) (Bit701 SEC || 00–99|-! 1| 0 || colspan=Zero)"3" | 10 SEC || colspan="4" | SECONDS || 00–59 |-! 2 Minutes (BCD 00h..59h) (Bit7| 0 || colspan=Zero)"3" | 10 MIN || colspan="4" | MINUTES || 00–59 |-! rowspan="2" | 3 Hours (BCD 01h..12h or 00h..23h) (Bit5| rowspan="2" | 12/24 || rowspan="2" | 0 || AM/PM when Bit7|| 10 HOUR || colspan=12"4" rowspan = "2" | HOUR || 01–12|-hour mode) (Bit6| colspan=Zero)"2" | 10 HOUR || 00–23 |-! 4 Day of Week (01h..07h) (Bit4=Disable Reset input, Bit5=Disable | 0 || 0 || /OSC, stop clock) (Bit3,6,7|| /RST || 0 || colspan=Zero)"3" | DAY || 01–07 5 Day (BCD 01h..31h) (Bit6|-7! 5| 0 || 0 || colspan=Zero)"2" | 10 DATE || colspan="4" | DATE || 01–31|- ! 6 Month (BCD 01h..12h) (Bit5| 0 || 0 || 0 || 10 MONTH || colspan="4" | MONTH || 01–12|-! 7| colspan=Zero)"4" | 10 YEAR || colspan="4" | YEAR || 00–99 7 Year (BCD 00h.|} Legend:* /OSC controls the oscillator.99h)When set to "0", the oscillator turns on and the real time clock begins to increment* When the /RST bit is set to "0", a low input on the reset pin of the chip will cause the Time Chip to abort data transfer without changing data in the timekeeping registers <br>

* ([[media:MF2_RRB.DSK|MF2_RRB.DSK]] - Vortex disc with , containing the TimeRom+ CP/M driver) * [[Media:DXS RTC - none such..User Manual.?pdf|DXS RTC User Manual]]