>BEGIN
>. WHILE forever
>. . IF the timer overflow flag is set
>. . . Increment Period_Hi
>. . IF the event has occurred
>. . . Copy the timer contents to Period_Lo
>. . . IF the timer overflow flag is set
>. . . . Increment Period_Hi
>. . . ENDIF
>. . . Process the event Period
>. . ENDIF
>. ENDWHILE
>END
>
>As can be seen a problem can occur when a timer overflow occurs
>between checking the overflow bit and reading the timer contents.
>Even if the overflow check is done immediately befor or after
>reading the timer contents, the broblem will still exist.

        Peter, consider the following:

                repeat
                    if overflow then
                        begin
                        hi := hi + 1;
                        clear overflow
                        end{if};
                    lo := timer
                until not overflow

___Bob