IBM 5150 Technical Reference page 281

machine code. The machine language used for entering text and
program instructions onto the recording medium or into storage
and which is subsequently used for processing and printout.
machine language. (1) A language that is used directly by a
machine.
(2)
Deprecated term for computer instruction code.
magnetic disk.
(1)
A flat circular plate with a magnetizable
surface layer on which data can be stored by magnetic recording.
(2)
See also diskette.
main storage.
(1)
Program-addressable storage from which
instructions and other data can be loaded directly into registers
for subsequent execution or processing.
(2)
Contrast with
auxiliary storage.
mark. A symbol or symbols that indicate the beginning or the end
of a field, of a word, of an item of data, or of a set of data such as
a file, a record, or a block.
mask.
(1) A
pattern of characters that is used to control the
retention or elimination of portions of another pattern of
characters.
(2)
To use a pattern of characters to control the
retention or elimination of portions of another pattern of
characters.
masked. Synonym for disabled.
matrix.
(1) A
rectangular array of elements, arranged in rows and
columns, that may be manipulated according to the rules of matrix
algebra.
(2)
In computers, a logic network in the form of an array
of input leads and output leads with logic elements connected at
some of their intersections.
matrix printer. A printer in which each character is represented
by a pattern of dots; for example, a stylus printer, a wire printer.
Synonymous with dot printer.
Mb. 1 048 576 bytes.
mega (M). Prefix 1 000 000.
Glossary-20