DASK
Encyclopedia
The DASK was the first computer
in Denmark
. It was commissioned in 1955, designed and constructed by Regnecentralen
, and began operation in September 1957. DASK is an acronym for Dansk Algoritmisk Sekvens Kalkulator or Danish Algorithmic Sequence Calculator. Regnecentralen almost didn't allow the name, as the word dask means "slap" in Danish. In the end however, it was named so as it fit the pattern of the name BESK
, the Swedish
computer which provided the initial architecture for DASK.
DASK traces its origins to 1947 and a goal set by Akademiet for de Tekniske Videnskaber (Academy for the Technical Sciences or Academy of Applied Sciences), which was to follow the development of the modern computing devices
. Initial funding was obtained through the Ministry of Defence (Denmark)
as the Danish Military
had been given a grant through the Marshall Plan
for cipher machines
for which the military saw no immediate need.
Originally conceived to be a copy of BESK
, the rapid advancement in the field allowed improvements to be made during the development such that in the end, it was not a copy of BESK. The DASK was a one-off design that took place in a villa. The machine became so big that the floor had to be reinforced to support its mass of 3.5 metric tons.
DASK is notable for being the subject of one of the earliest ALGOL
implementations, referred to as DASK ALGOL , which counted Jørn Jensen
and Peter Naur
among its contributors.
machine based on the Swedish BESK
design. As described in 1956, it contained 2500 vacuum tubes, 1500 solid-state elements, and required a three-phase power
supply of at least 15 kW.
Fast storage was 1024 40-bit words of magnetic core memory
(cycle time 5µs), directly addressable as 1024 full or 2048 half-words. This was complemented by an additional 8192 words of backing store on magnetic drum
(3000 rpm). A full word stored 40-bit numbers in two's-complement form, or two 20-bit instructions.
In addition to two accumulators
, the DASK had three index register
s, which could be used to modify the address of most instructions. An instruction word consisted of 11 bits for an address, two bits for index register selection, and 7 bits for the operation code and its modifiers.
Operations included addition and subtraction (56 µs), multiplication and division (364 µs), binary shift and bitwise conjunction.
Peripherals initially included 5-bit paper tape (400 cps read time) and teletypewriter (12 cps); magnetic tape and other peripherals were added later on.
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
in Denmark
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
. It was commissioned in 1955, designed and constructed by Regnecentralen
Regnecentralen
Regnecentralen, or RC for short, was the first Danish computer company, founded on October 12, 1955. Through the 1950s and 60s they designed a series of computers, originally for their own use, and later to be sold commercially. Descendants of these systems sold well into the 1980s...
, and began operation in September 1957. DASK is an acronym for Dansk Algoritmisk Sekvens Kalkulator or Danish Algorithmic Sequence Calculator. Regnecentralen almost didn't allow the name, as the word dask means "slap" in Danish. In the end however, it was named so as it fit the pattern of the name BESK
BESK
BESK was Sweden's first electronic computer, using vacuum tubes instead of relays. It was developed by Matematikmaskinnämnden and during a short time it was the fastest computer in the world. The computer was completed in 1953 and in use until 1966...
, the Swedish
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
computer which provided the initial architecture for DASK.
DASK traces its origins to 1947 and a goal set by Akademiet for de Tekniske Videnskaber (Academy for the Technical Sciences or Academy of Applied Sciences), which was to follow the development of the modern computing devices
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
. Initial funding was obtained through the Ministry of Defence (Denmark)
Ministry of Defence (Denmark)
The Ministry of Defence of Denmark is a ministry in the Danish government. It is charged with overall planning, development, and strategic guidance of the entire area of responsibility of the Danish Defence minister, including the armed forces and the emergency management sector...
as the Danish Military
Military of Denmark
The armed forces of the Kingdom of Denmark, known as the Danish Defence is charged with the defence of the Kingdom of Denmark.The Chief of Defence is the head of the Danish Armed Forces, and is head of the Defence Command which is managed by the Ministry of Defence. Constitutionally, the...
had been given a grant through the Marshall Plan
Marshall Plan
The Marshall Plan was the large-scale American program to aid Europe where the United States gave monetary support to help rebuild European economies after the end of World War II in order to combat the spread of Soviet communism. The plan was in operation for four years beginning in April 1948...
for cipher machines
Encryption
In cryptography, encryption is the process of transforming information using an algorithm to make it unreadable to anyone except those possessing special knowledge, usually referred to as a key. The result of the process is encrypted information...
for which the military saw no immediate need.
Originally conceived to be a copy of BESK
BESK
BESK was Sweden's first electronic computer, using vacuum tubes instead of relays. It was developed by Matematikmaskinnämnden and during a short time it was the fastest computer in the world. The computer was completed in 1953 and in use until 1966...
, the rapid advancement in the field allowed improvements to be made during the development such that in the end, it was not a copy of BESK. The DASK was a one-off design that took place in a villa. The machine became so big that the floor had to be reinforced to support its mass of 3.5 metric tons.
DASK is notable for being the subject of one of the earliest ALGOL
ALGOL
ALGOL is a family of imperative computer programming languages originally developed in the mid 1950s which greatly influenced many other languages and became the de facto way algorithms were described in textbooks and academic works for almost the next 30 years...
implementations, referred to as DASK ALGOL , which counted Jørn Jensen
Jørn Jensen
Jørn Jensen, one of the earliest Danish programmers. Examined as a mechanical engineer and had worked with electromechanical construction. In 1958 employed at the Danish Regnecentralen, and very soon exhibited an extraordinary programming skill...
and Peter Naur
Peter Naur
Peter Naur is a Danish pioneer in computer science and Turing award winner. His last name is the N in the BNF notation , used in the description of the syntax for most programming languages...
among its contributors.
Architecture
The DASK was a vacuum tubeVacuum tube
In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...
machine based on the Swedish BESK
BESK
BESK was Sweden's first electronic computer, using vacuum tubes instead of relays. It was developed by Matematikmaskinnämnden and during a short time it was the fastest computer in the world. The computer was completed in 1953 and in use until 1966...
design. As described in 1956, it contained 2500 vacuum tubes, 1500 solid-state elements, and required a three-phase power
Three-phase electric power
Three-phase electric power is a common method of alternating-current electric power generation, transmission, and distribution. It is a type of polyphase system and is the most common method used by grids worldwide to transfer power. It is also used to power large motors and other heavy loads...
supply of at least 15 kW.
Fast storage was 1024 40-bit words of magnetic core memory
Magnetic core memory
Magnetic-core memory was the predominant form of random-access computer memory for 20 years . It uses tiny magnetic toroids , the cores, through which wires are threaded to write and read information. Each core represents one bit of information...
(cycle time 5µs), directly addressable as 1024 full or 2048 half-words. This was complemented by an additional 8192 words of backing store on magnetic drum
Drum memory
Drum memory is a magnetic data storage device and was an early form of computer memory widely used in the 1950s and into the 1960s, invented by Gustav Tauschek in 1932 in Austria....
(3000 rpm). A full word stored 40-bit numbers in two's-complement form, or two 20-bit instructions.
In addition to two accumulators
Accumulator (computing)
In a computer's central processing unit , an accumulator is a register in which intermediate arithmetic and logic results are stored. Without a register like an accumulator, it would be necessary to write the result of each calculation to main memory, perhaps only to be read right back again for...
, the DASK had three index register
Index register
An index registerCommonly known as a B-line in early British computers. in a computer's CPU is a processor register used for modifying operand addresses during the run of a program, typically for doing vector/array operations...
s, which could be used to modify the address of most instructions. An instruction word consisted of 11 bits for an address, two bits for index register selection, and 7 bits for the operation code and its modifiers.
Operations included addition and subtraction (56 µs), multiplication and division (364 µs), binary shift and bitwise conjunction.
Peripherals initially included 5-bit paper tape (400 cps read time) and teletypewriter (12 cps); magnetic tape and other peripherals were added later on.
External links
- Early Computing in Denmark
- HOPL entry for DASK Algol
- Dansk Datahistorisk Forening Virtual Museum (in DanishDanish languageDanish is a North Germanic language spoken by around six million people, principally in the country of Denmark. It is also spoken by 50,000 Germans of Danish ethnicity in the northern parts of Schleswig-Holstein, Germany, where it holds the status of minority language...
) - Technical description of the DASK (in DanishDanish languageDanish is a North Germanic language spoken by around six million people, principally in the country of Denmark. It is also spoken by 50,000 Germans of Danish ethnicity in the northern parts of Schleswig-Holstein, Germany, where it holds the status of minority language...
)