Decimal clock (maths problem) by Steve Smith .

In a moment of wild abandon a party piece was conceived :- THE DECIMAL CLOCK The basic code is simple and published in the ECH this can easily be converted for the decimal clock see table:- dec time conv time periods 1 1 day 20 24 hours 2000 1440 minutes 200000 86400 seconds relationship 2.314815 The problem arises when the ability to convert or count in conventional time as well is also required. The conversion factor for the seconds count is not good 'easy' math's and this forced a serious overload in the thinking department. The basis is the '57 based alarm clock as the app note driving multiplexed LED display and keyboard. If the crystal is recalculated to operate the decimal clock accurately then the problem becomes clear. How do you keep track of time using the same timebase with only the limited amount of RAM that the '57 contains? Duplicating the RAM registers I think is OK but how do you process the number of counts to increment both time periods accurately. The clock is not using interrupts as it waits in one location for TMR0 to roll over this then causes a counter to increment and handle the other functions display keyboard alarm ect. Can anyone help with this perplexing problem please ..... Cheers Steve.....