
28 Fundamentals of Computer Programming and IT
A magnetic tape is physically marked to indicate the
location from where r
eading and writing on tape is to
begin (BOT or beginning of tape) and end (EOT or end
of tape). The length of tape between BOT and EOT is
referred to as the usable recording (reading/writing) sur-
face. BOT/EOT markers are usually made up of short
silver strips of reflective type. These markers are sensed
by an arrangement of lamps and/or photodiode sensors
to indicate the location from where reading and writ-
ing is to begin and end. On a magnetic tape, data is
recorded in form of blocks where each block consists of
a grouping ...