IBM 5170 Technical Reference page 414

duty cycle. In the operation of a device, the ratio of on time to
idle time. Duty cycle is expressed as a decimal or percentage.
dynamic memory. RAM memory using transistors and capacitors
as the memory elements. This memory requires a refresh
(recharge) cycle every few milliseconds. Contrast with static
memory.
EBCDIC. Extended binary-coded decimal interchange code.
ECC. Error checking and correction.
edge connector. A terminal block with a number of contacts
attached to the edge of a printed-circuit board to facilitate
plugging into a foundation circuit.
EIA. Electronic Industries Association.
electromagnet. Any device that exhibits magnetism only while an ,,-.....,
electric current flows through it.
enable. To initiate the operation of a circuit or device.
end of block (EOB). A code that marks the end of a block of
data.
end of file (EOF). An internal label, immediately following the
last record of a file, signaling the end of that file. It may include
control totals for comparison with counts accumulated during
processing.
end-of-text (ETX). A transmission control character used to
terminate text.
end-of-transmission (EOT). A transmission control character
used to indicate the conclusion of a transmission, which may have
included one or more texts and any associated message headings.
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