Once common words no longer heard . . .
More and More Obsolete Computing Terms
©Conrad Weisert, Information Disciplines, Inc.,
30 November 2016
Those of us who've been in the computing / data-processing field
for some time, are noticing that many professional and technical
terms that we once used every day are rarely heard these days.
Younger colleagues are sometimes puzzled upon hearing or
reading some of those terms.
I'm starting this little collection, therefore, to remind readers
how much our profession has changed just within a few decades,
and perhaps also to help clarify old documentation.
- Register used for calculations. (replaced
by multiple general registers)
- Information represented in BCI or EBCDIC
- Binary-coded information, a 6-bit
character representation (sometimes BCD,
binary-coded decimal) derived from punched-card codes.
- Same as physical record.
- card image
- (a) Character string representing the contents of an
80-column punched card.
(b) Bit array (usually 12 X 72) with 1's representing
holes in a punched card.
- core dump
- Printed contents of main memory or a part
of main memory, used as a debugging aid.
- carriage tape
- A perforated paper loop used to control rapid
vertical movement of continuous paper in a line printer.
- drum card
- A punched card used to control an IBM keypunch machine to advance to the beginning of each field, default to certain character types within the field, duplicate a field from the previous card, etc., in order to enhance the speed and accuracy of offline batch data entry.
- An 8-bit extension of BCI used by IBM 360
and other third-generation computers; replaced by
- Encoding scheme for representing letters,
digits, and punctuation as holes on a punched card. Sometimes
casually used as a synonym for BCI.
- index reigister
- Register used mainly for address
modification or counting rather than general computation.
- JCL (Job Control Language)
- Command language for batch processing
on OS/360 and similar batch operating systems.
- (instruction) Same as branch; used in Univac and CDC computer
- logical record
- Contiguous data items written to or
read from a file as a unit.
- (a). Supervisory control program in an opeating system.
(b). Screen display device.
- object deck
- Punched card output from a compiler or
assembler containing object code in absolute or relocatable
- overpunched sign
- Punched card representation of a
plus sign or a minus sign in the same column with a digit to
The result was often the same code as an alphabetic character,
relying on program logic to make the distinction.
- packed decimal
- Numeric representation using 4 bits for each
decimal digit (i.e. 2 digits per byte), supported by IBM 360 and
- A temporary usually emergency program correction.
- physical record
- Contiguous logical records written to or
read from a magnetic tape or disk as a unit, in order to reduce
the space between records.
- relocatable binary
- Compiler output (object deck) in which
a loader program would increment certain fields (memory addresses)
by the actual origin of the program component in memory.
- source deck
- Punched cards containing characters
comprising a module in a programming language; input to
a compiler or assembler.
- (instruction) Same as branch; used in IBM scientific computer
- word mark
- Bit position reserved for separating
data items (words) on variable-word-length machines, such
as the IBM 1401.
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Last modified 27 January 2017