On Sat, 15 Dec 2007 10:36:39 +0100 (CET) Univac made extensive use of flying head drums during the 1960's. Systems as late as the 1108 used them. AFAIK, they all had "FH" prefixes to identify them as such. Bitsavers has the manual on the one I used on the 1108, the FH-880: http://www.bitsavers.org/pdf/univac/1107/UT-2560_FH- 880_Drum_Dec61.pdf IIRC, the FH-880 spun quite fast. On the other hand, the "big drum" on the 1108, the FASTRAND II, was a slow sewer-pipe of a monster. Here's a document that accurately describes it: http://www.fourmilab.ch/documents/univac/fastrand.html IIRC, the head movement was accomplished through an system of levers connected to solenoids that directly converted a binary code to a physical position. Regarding magnetostrictive delay line, bitsavers also has a collection of PB250 documents that might be worth a perusal: http://www.bitsavers.org/pdf/packardBell/PB-250/ Hope this helps, Chuck