Y=0;
until Y>= 1000 do {
X++;}
Wait... what?
Just to get in the right era, if I remember correctly, it was Fortran II that was in use back then... I don't remember do..while (or while..do) being in the syntax then. IIRC that came way later, maybe Fortran 77? Also back in the cobwebs, I seem to remember that it was running on an IBM 1620, the storage was - don't remember if it was a hard drive thing or a drum - the size of a rain barrel, and of course, input was punch cards...
That info just might date me a bit older than you were thinking, but then, maybe not.. ;-)