this type of thing is usually done in the middle of some process

like you're loading something doing something,let user know it's not frozen, i'd put it in the middle of a main loop drawing one dot per loop cycle.

temp$ = "Loading something"
numofdots = 3

DO

'main process, could be any loop


i = i + 1
LOCATE 1, 1
j = i MOD (numofdots + 1)
PRINT temp$ + STRING$(j, ".") + SPACE$(numofdots - j);
_DELAY .25
LOOP