Mountain Hardware - 100,000 Day Clock Board
This board was designed to provide the date and time for S-100 systems!
Time events in 100 usec. up to 100,000 days (273 years) were possible. The board
could call any one of the S-100 interrupt lines.
The manual for this board can be
obtained
here.
Here is the relevent software listing to run the board
MMT100K.Z80 &
CLOCK.LIB.Z80
