nIt weighed more than 27,000 kg
(60,000 lb) and contained more than 18,000 vacuum tubes. Roughly
2000 of the computerís vacuum tubes were replaced each month by a
team of six technicians. Many of ENIACís first tasks were for military
purposes, such as calculating ballistic firing tables and designing
atomic weapons. Since ENIAC was initially not a stored program machine,
it had to be reprogrammed for each task.