No-Slot Clock

The No-Slot Clock project was started about mid 2014 by Henry from ReActiveMicro, and was officially released on April 12th, 2015. It was inspiration by his work on the DClock project. This was an Ultimate-Micro release, and all newer v1.3 PCBs bare the UM logo.

History

While working on the DClock project Henry learned how phantom clocks work. With this understanding he was able to see how a new and better No-Slot Clock design could be produced.

When Henry started the No-Slot Clock project he purchased back stock of the DS1215 Clock ICs from James Littlejohn of 8bitsystem.com on June 13th, 2014. James had abandoned the DClock project and wasn't using the stock Henry had previously sold to him.

Henry then started CAD and design work for his version of the No-Slock Clock to come up with a better design that didn't use two DIP Sockets soldered together, as Dallas did with their "SmartWatch" Clock design. The reason for this is not all signals are passed from the systems data bus to the ROM or RAM IC the DS1216E No-Slock Clock is installed under.

Theory of Operation: The /CE (Chip Enable) signal from the system's DIP Socket passes through the DS1215 Clock IC (in Pin11, out pin10). When the DS1215 Clock IC recognizes a certain sequence of bits on A0 (Pin6) and A2 (Pin3) the ROM's /CE pin is held high by the DS1215 Clock IC and is in essence "disconnected" from the system's data bus. This allows the No-Slock Clock's software to communicate directly with the DS1215 Clock IC without the ROM interfering.