I’ve recently created my third board for the RC2014 - a real time clock based on the DS1302 Real time clock IC.
Once again, the schematic of the board was derived from that of the Zeta 2 computer, meaning adding support to the board was fairly trivial as code for reading from the DS1302 was already included in RomWBW, Wayne Warthen’s CP/M distribution.
The schematics and gerbers are available on GitHub and I’ve also made a few PCBs available for sale on Tindie