Dobbertin Smart Watch

The Dobbertin Smart Watch was produced by Dobbertin Industrie Elektronik, a German company. This real time clock was relative wide spread in the 80ies and 90ies.

Technicals

The Smart Watch consists out of the RTC itself and an EPROM expansion with a lot of RSX commends. 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 2010!

Dallas Semiconductors Smart Watch

Forward: Whether or not the Dobbertin Smart Watch does actually contain chipset from Dallas Semiconductors is still unknown... The term "Smart Watch" and the technique of inserting the RTC into a ROM socket does indicate that the Dobbertin RTC has some relation to the Dallas product... It might be exactly that hardware, or similar compatible or incompatible hardware, or something entirely different... can somebody verify which chip(s) are used in the Dobbertin RTC ?

The 28pin Smart Watch (DS1216) is an adapter that can inserted in standard ROM sockets, a ROM chip can be mounted piggyback on the adapter, 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 address, too.

Media:DS1216-smart-watch.pdf - Datasheet for 28pin Dallas Smart Watch Media:DS1315-phantom-time-chip.pdf - Datasheet for 16pin Dallas Phantom Time Chip Media:DS1216-app-note-52.pdf - Application Note on Smart Watch and Phantom Time Chip

Software

• The TimeROM+ Software provides RSX commands to use the RTC under BASIC.
• Support for CP/M Plus was provided. The TIMEROM+.COM program sets the software clock according to the RTC.
• The Smart Watch is also supported by FutureOS.

Source Code

(Have to find out how to implement it here... please be patient)