I recently acquired (Thanks Lee!) a copy of Time Minder for the T200. After 
loading it up I realized that it suffered from a Y2K bug. Different from what 
we see on Menu which is just a fixed value. Time Minder calculates all dates 
from an epoch of Jan 1 1900 and ignores the DAY$ value in the clock. So when 
calculating calendar, there was no way to make it work on dates above December 
31st, 1999. It pulls the Year, Month and Day values from the clock chip but 
then does it's own calculations. This makes leap days valid. But trying to 
build a calendar for 2015 results in a 1915 calendar.

After some digging with Virtual-T, I replaced a LDA command with a CALL to 6 
new bytes of code. There I loaded the Year and added 100 to the accumulator. 
This makes all the calendars appear perfectly on dates past 2000.
The only problem now is displaying 20 instead of 19 on the screen. For some 
reason finding that code has eluded me, but the software is not functional.

There are 4 version of Time Minder, two for loading from the cassette port and 
two from the DVI/TS-Dos. Right now I have the DVI/TS-Dos versions working but 
still displaying 19 instead of 20 for the century.
My next step is to apply the epoch year fix to the cassette versions and then 
try to fix the display issue.

Kurt

Reply via email to