were introduced to support the new 8-bit characters that it used. The end of a file was designated by a special recorded pattern called a tape mark, and end of the recorded data on a tape by two successive tape marks. The physical beginning and end of usable tape was indicated by reflective adhesive strips of aluminum foil placed on the backside.

Recording density increased over time. Common 7-track densities started at 200 characters per inch (CPI), then 556, and finally 800; 9-track tapes had densities