I believe you meant 1981. There was no travel ban, but there was a travel advisory. Basicaly it stated that while Visas were obtainable at the airport in Pakistan, they were not good for any more than 30 days, and they could not be renewed. Staying longer, or if the travel was business related, required getting the Visa in adance, and that took a long time. Since Obama's trip was tagged on to the end of a visit to his mother and sister in Indonesia, it seems unlikely they would have gotten it in advance, but possible. However they also likely did not stay for more than 30 days, so he would not have needed to get the one in advance. Probably the same deal if he traveled on an Indonesian passport.
Sorry, you’re correct - 1981. The “travel ban” is still occasionally proclaimed on these threads, even though repeatedly debunked.