The TCU-150 from Digital Pathways is a real time calander clock which does not forget the time(for up to 3 months) when the power is turned off on the computer. Two support tasks are provided to utilize its capabilities: one to set the system time automatically and one to update the internal time of the TCU-150. Further HELP is provided with the keywords CSR CSR registers for the TCU-150 TIMSET Automatically setting the system time. SETTIM Setting the internal TCU-150 time. 2 CSR 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 760770 YR/MO/DAY ! YEAR ! MONTH ! DAY ! 760772 HR/MINS - - - ! HOUR ! - - ! MINUTE ! 760774 SECONDS - - - - - - - - - - ! SECOND ! 760776 READ STATUS H Y - - - - - - R - - - - - - - where - bit unused Y Year/Month/Day being set H Hour/Minute being set R TCU-150 ready Each of the registers is read only except when setting the TCU-150. To set the TCU-150, setting any value in either the YR/MO/DAY or HR/MINS register will cause the data in that register to rapidly cycle. Placing any data into the SECONDS register will cause the rapid cycling to stop. 2 TIMSET TIMSET is a small privleged task(only rebuild it if CSR's for TCU-150 change) which gets the time from the TCU-150, creates a TIME command and SPAWNS the command to MCR. It will only work from a privileged terminal. 2 SETTIM To set the TCU-150's internal clock, first correctly set the system time using the MCR TIME command, eg. TIME 10:31:40 25-SEP-79 Then RUN $SETTIM. SETTIM will do a GTIM$ directive to get the system time and then set the TCU-150 system clock. SETTIM should be run at a higher priority than any other user tasks so that it will not be stopped until it sets the time and exits.