The basic way is just to store the current TIMER() in a variable (before a DO/LOOP). A check within the DO/LOOP to see if the current TIMER() is more than the variable + however many milliseconds you wish the timer to be. Then make the variable equal the current TIMER() to do it again.
` Set a timer
tim=timer()
do
` Check if it's time to print (1000 = 1 second)
if timer()=>tim+1000
` Show the results
print "Timer is now at "+str$(timer())+"."
` Reset timer
tim=timer()
endif
loop
Another way is reducing the TIMER() down to actual seconds by using the formula (TIMER()-oldtimer)/1000 to get the seconds elapsed from the stored timer vs the current TIMER().
` Store the current timer
tim=timer()
do
` Check if a second has gone by (if current seconds is more than oldseconds)
if (timer()-tim)/1000 >OldSeconds
` Calculate seconds
Seconds=(timer()-tim)/1000
` Show the another second has gone by
text 0,0,"It's been "+str$(Seconds)+" seconds since this program started."
` Save previous number of seconds
OldSeconds=Seconds
endif
loop
