 The Minuteman-I Autonetics D-17 flight computer used a rotating air bearing magnetic disk holding 2,560 "cold-stored" words in 20 tracks (write heads disabled after program fill) of 24 bits each and one alterable track of 128 words.The time for a D-17 disk revolution was 10 ms.The D-17 also used a number of short loops for faster access to intermediate results storage.