I'm responding to a very old posting that I came upon quite accidentally. The tape in question is a "Precon" tape used by the IBM Magnetic Tape Selectric Composer system introducted by IBM in 67. I worked for IBM at the time and subsequently used a lot of this equipment in my graphic arts/typesetting business. The tape was used to "pre-condition" the IBM MT/SC based on what you were trying to do, i.e., set straight text type, set tabular type, set type using an outline format, or set horizontal rules. It was sort of a "download" of code to get the machine set up for what you were about to do because all of the code could not be resident in the MT/SC at the same time. The Precon 256 was used for straight columnar text type; the Precon 260 was used for text in outline format (1.(a).1 etc), Precon 261 was used for tabular work--columns and Precon 259 was used to create automatic horizontal rules specifically for use in classified ads. Precon 263 was a diagnostic Precon. There were many other Special Feature Precons such as 340, 341, 342 and 343 for automatic letter writing functions and automatic paragraph selection, etc. Interesting stuff. Good equipment--I liked using it very much. P.S.--The tape has no value--other than memories. At the time the tape cost about 40 bucks--the MT/SC cost about $35,000! Steve Eichner Manager, Business Systems Standards & Assurance Rainbow Information Systems 516-803-5102