![NCR-315, pt](https://upload.wikimedia.org/wikipedia/commons/8/85/NCR-315%2C_pt._2_%282231627851%29.jpg)
The NCR 315 Data Processing System, released in January 1962 by
NCR,
is a second-generation
computer
A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as C ...
. All
printed circuit board
A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in Electrical engineering, electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a L ...
s use
resistor–transistor logic Resistor–transistor logic (RTL) (sometimes also transistor–resistor logic (TRL)) is a class of digital circuits built using resistors as the input network and bipolar junction transistors (BJTs) as switching devices. RTL is the earliest class o ...
(RTL) to create the various logic elements. It uses
12-bit
Possibly the best-known 12-bit CPU is the PDP-8 and its relatives, such as the Intersil 6100 microprocessor produced in various forms from August 1963 to mid-1990. Many analog to digital converters (ADCs) have a 12-bit resolution. Some PIC micr ...
''slab'' memory structure using
magnetic-core memory
Magnetic-core memory was the predominant form of random access, random-access computer memory for 20 years between about 1955 and 1975.
Such memory is often just called core memory, or, informally, core.
Core memory uses toroids (rings) of a ...
. The instructions can use a memory slab as either two
6-bit alphanumeric characters or as three
4-bit
In computer architecture, 4-bit integers, or other data units are those that are 4 bits wide. Also, 4-bit central processing unit (CPU) and arithmetic logic unit (ALU) architectures are those that are based on registers, or data buses of that si ...
BCD digits. Basic memory is 5000 "slabs" (10,000 characters or 15,000 decimal digits) of handmade core memory, which is expandable to a maximum of 40,000 slabs (80,000 characters or 120,000 decimal digits) in four refrigerator-size cabinets. The main processor includes three cabinets and a console section that houses the power supply, keyboard, output writer (an
IBM electric typewriter), and a
panel
Panel may refer to:
Arts and media Visual arts
* Panel (comics), a single image in a comic book, comic strip or cartoon; also, a comic strip containing one such image
*Panel painting, in art, either one element of a multi-element piece of art ...
with lights that indicate the current status of the program counter, registers, arithmetic accumulator, and system errors. Input/Output is by direct parallel connections to each type of peripheral through a two-cable bundle with 1-inch-thick cables. Some devices like
magnetic tape
Magnetic tape is a medium for magnetic storage made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany in 1928, based on the earlier magnetic wire recording from Denmark. Devices that use magne ...
and the
CRAM
Cram may refer to:
* Cram (surname), a surname, and list of notable persons having the surname
* Cram.com, a website for creating and sharing flashcards
* Cram (Australian game show), a television show
* ''Cram'' (game show), a TV game show that ...
are daisy-chained to allow multiple drives to be connected.
The central processor (315 Data Processor) weighed about .
Later models in this series include the 315-100 and the 315-RMC (Rod Memory Computer).
Memory organization
The addressable unit of memory on the NCR 315 series is a "slab", short for "syllable", consisting of 12 data
bit
The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represente ...
s and a
parity bit
A parity bit, or check bit, is a bit added to a string of binary code. Parity bits are a simple form of error detecting code. Parity bits are generally applied to the smallest units of a communication protocol, typically 8-bit octets (bytes) ...
.
Its size falls between a
byte
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit ...
and a typical
word
A word is a basic element of language that carries an semantics, objective or pragmatics, practical semantics, meaning, can be used on its own, and is uninterruptible. Despite the fact that language speakers often have an intuitive grasp of w ...
(hence the name, '
syllable
A syllable is a unit of organization for a sequence of speech sounds typically made up of a syllable nucleus (most often a vowel) with optional initial and final margins (typically, consonants). Syllables are often considered the phonological "bu ...
').
A slab may contain three digits (with
at sign
The at sign, , is normally read aloud as "at"; it is also commonly called the at symbol, commercial at, or address sign. It is used as an accounting and invoice abbreviation meaning "at a rate of" (e.g. 7 widgets @ £2 per widget = £14), but ...
,
comma
The comma is a punctuation mark that appears in several variants in different languages. It has the same shape as an apostrophe or single closing quotation mark () in many typefaces, but it differs from them in being placed on the baseline ...
,
space
Space is the boundless three-dimensional extent in which objects and events have relative position and direction. In classical physics, physical space is often conceived in three linear dimensions, although modern physicists usually consider ...
,
ampersand
The ampersand, also known as the and sign, is the logogram , representing the conjunction "and". It originated as a ligature of the letters ''et''—Latin for "and".
Etymology
Traditionally in English, when spelling aloud, any letter that ...
,
point
Point or points may refer to:
Places
* Point, Lewis, a peninsula in the Outer Hebrides, Scotland
* Point, Texas, a city in Rains County, Texas, United States
* Point, the NE tip and a ferry terminal of Lismore, Inner Hebrides, Scotland
* Point ...
, and
minus
The plus and minus signs, and , are mathematical symbols used to represent the notions of positive and negative, respectively. In addition, represents the operation of addition, which results in a sum, while represents subtraction, resulti ...
treated as digits) or two alphabetic characters of six bits each. A slab may contain a
decimal
The decimal numeral system (also called the base-ten positional numeral system and denary or decanary) is the standard system for denoting integer and non-integer numbers. It is the extension to non-integer numbers of the Hindu–Arabic numeral ...
value from -99 to +999.
A numeric value contains up to eight slabs. If the value is negative then the minus sign is the leftmost digit of this row. There are instructions to transform digits to or from alphanumeric characters. These commands use the
accumulator, which has a maximum length of eight slabs. To accelerate the processing the accumulator works with an effective length.
NCR 315-100
The NCR 315-100 is the second version of the original 315. It too has a 6-microsecond clock cycle, and from 10,000 to 40,000 slabs of memory.
The 315-100 series console I/O incorporates a Teletype printer and keyboard in place of the original 315's IBM typewriter.
The primary difference between the older NCR 315 and the 315-100 was the inclusion of the Automatic Recovery Option (ARO). One of the problems with early generation of computers was that when a memory or program error occurred, the system would simply turn on a red light and halt. The normal recovery process was to copy all register and counter setting from the console light panel, and to restart the program that was running at the time of the error, usually from the very beginning of the program.
The upgrade to the 315 required the removal of approximate 1800
wire-wrap
Wire wrap is an electronic component assembly technique that was invented to wire telephone crossbar switches, and later adapted to construct electronic circuit boards. Electronic components mounted on an insulating board are interconnected by l ...
ped connection on the backplane, and the installation of approximately 2400 new point-to-point wired connection.
NCR 315-RMC
The NCR 315-RMC, released in July 1965, was the first commercially available computer to employ
thin-film memory
Thin-film memory is a high-speed alternative to core memory developed by Sperry Rand in a government-funded research project.
Instead of threading individual ferrite cores on wires, thin-film memory consisted of 4-micrometre thick dots of per ...
. This reduced the clock cycle time to 800 nanoseconds. It also included
floating-point
In computing, floating-point arithmetic (FP) is arithmetic that represents real numbers approximately, using an integer with a fixed precision, called the significand, scaled by an integer exponent of a fixed base. For example, 12.345 can b ...
logic to allow scientific calculations, while retaining the same instruction set as previous NCR 315 and
NCR 315-100
The NCR 315 Data Processing System, released in January 1962 by NCR, is a second-generation computer. All printed circuit boards use resistor–transistor logic (RTL) to create the various logic elements. It uses 12-bit ''slab'' memory structure ...
.
The thin film is wrapped around "rods" to allow faster reading and writing of memory.
The follow-on to the 315-RMC was the
NCR Century NCR may refer to:
* NCR Corporation, formerly National Cash Register
* "No carbon required" carbonless copy paper
* A Nature Conservation Review, UK book
* Naval Construction Regiment of US Navy Seabees
* New Carrollton station Amtrak code
* Not cr ...
series.
Available languages
* NCR Assembler Language
* National Electronic Autocoding Technique (NEAT)
— similar to
Autocoder
Autocoder is any of a group of assembly language, assemblers for a number of IBM computers of the 1950s and 1960s.
The first Autocoders appear to have been the earliest assemblers to provide a Macro (computer science), macro facility.
Terminolo ...
*
COBOL
COBOL (; an acronym for "common business-oriented language") is a compiled English-like computer programming language designed for business use. It is an imperative, procedural and, since 2002, object-oriented language. COBOL is primarily us ...
* BEST— a high-level preproocesor for NEAT
Available peripherals
*
NCR-321 Communications Controller
*
NCR-340 The NCR-340 was NCR Corporation, NCR's first line "High Speed" 300-line-per-minute computer printer. It used a drum made up of 120 (later 132) hardened steel discs with the upper-case alphabet, the numbers 0-9 and a few special symbols. The discs w ...
600-LPM line printer
*
Magnetic tapes
Magnetic tape is a medium for magnetic storage made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany in 1928, based on the earlier magnetic wire recording from Denmark. Devices that use magnet ...
**
NCR-332 Magnetic tape drive (512 bpi)
**
NCR-333 Control Data
CDC
The Centers for Disease Control and Prevention (CDC) is the National public health institutes, national public health agency of the United States. It is a Federal agencies of the United States, United States federal agency, under the United S ...
tape drive (512 bpi)
**
NCR-334 Magnetic Tape Drive (200/512 bpi)
*
NCR-353 Magnetic Card Random Access Memory (
CRAM
Cram may refer to:
* Cram (surname), a surname, and list of notable persons having the surname
* Cram.com, a website for creating and sharing flashcards
* Cram (Australian game show), a television show
* ''Cram'' (game show), a TV game show that ...
)
*
Card Card or The Card may refer to:
* Various types of plastic cards:
**By type
***Magnetic stripe card
*** Chip card
*** Digital card
**By function
***Payment card
****Credit card
**** Debit card
****EC-card
****Identity card
****European Health Insur ...
and
paper tape
Five- and eight-hole punched paper tape
Paper tape reader on the Harwell computer with a small piece of five-hole tape connected in a circle – creating a physical program loop
Punched tape or perforated paper tape is a form of data storage ...
equipment
**
NCR-361 Paper Tape Reader
**
NCR-371 Paper Tape Punch
**
NCR-376 IBM Card Reader/Punch
**
NCR-380 2000 CPS High speed card reader
**
NCR-472 Card Reader, Paper Tape Reader/Punch
* NCR-???
Drum memory
Drum memory was a magnetic data storage device invented by Gustav Tauschek in 1932 in Austria. Drums were widely used in the 1950s and into the 1960s as computer memory.
For many early computers, drum memory formed the main working memory ...
*
NCR-402 MICR
Magnetic ink character recognition code, known in short as MICR code, is a character recognition technology used mainly by the banking industry to streamline the processing and clearance of cheques and other documents. MICR encoding, called the '' ...
Check Reader/Sorter
*
NCR-420 Optical Character Reader (
OCR)
*
NCR-407 High Speed MICR Check Reader/Sorter
See also
* ''
The Super Fight
''The Super Fight'' was a fictional boxing match between Rocky Marciano and Muhammad Ali shot in 1969 and released in 1970. At the time, Ali and Marciano were the only undefeated heavyweight champions in history and fans often debated who would w ...
'' – Used an NCR 315 to predict its outcome
*
Catena (computing)
In computing, a word is the natural unit of data used by a particular processor design. A word is a fixed-sized datum handled as a unit by the instruction set or the hardware of the processor. The number of bits or digits in a word (the ''word si ...
External links
Rod Memory description*
References
{{DEFAULTSORT:Ncr 315
Mainframe computers
Transistorized computers
NCR Corporation products