K-202 was a

16-bit 16-bit microcomputers are microcomputers that use 16-bit microprocessors. A 16-bit register can store 216 different values. The range of integer values that can be stored in 16 bits depends on the integer representation used. With the two ...

minicomputer A minicomputer, or colloquially mini, is a type of general-purpose computer mostly developed from the mid-1960s, built significantly smaller and sold at a much lower price than mainframe computers . By 21st century-standards however, a mini is ...

, created by a team led by

Polish Polish may refer to: * Anything from or related to Poland, a country in Europe * Polish language * Polish people, people from Poland or of Polish descent * Polish chicken * Polish brothers (Mark Polish and Michael Polish, born 1970), American twin ...

scientist A scientist is a person who Scientific method, researches to advance knowledge in an Branches of science, area of the natural sciences. In classical antiquity, there was no real ancient analog of a modern scientist. Instead, philosophers engag ...

Jacek Karpiński between 1970–1973 in cooperation with

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories and Crown Dependencies. * British national identity, the characteristics of British people and culture ...

companies Data-LoopData-Loop
/ref> and M.B. Metals. The machine could perform about 1

million instructions per second Instructions per second (IPS) is a measure of a computer's processor speed. For complex instruction set computers (CISCs), different instructions take different amounts of time, so the value measured depends on the instruction mix; even for c ...

, making it highly competitive with the US Data General SuperNOVA and UK CTL Modular One. Most other minicomputers of the era were significantly slower. Approximately 30 units were claimed to be produced. All units shipped to M.B. Metals were returned for service. Due to friction resulting from competition with

Elwro Elwro was a Polish company that manufactured mainframe and microcomputers from 1959 until 1989. Its plant was in Wrocław. Computer models included Odra (computer), Odra mainframe systems, and the List of ZX Spectrum clones#Elwro 800 Junior, Elwro ...

, a government-backed competitor, the production of K-202 was blocked and Karpiński thrown out of his company under the allegations of sabotage and embezzlement. Sometime later the K-202 had a successor, , hundreds of which were built.

Description

The K-202 was packaged in a metal box similar to other

s in overall size, and capable of being fit into a

19-inch rack A 19-inch rack is a standardized frame or enclosure for mounting multiple electronic equipment modules. Each module has a front panel that is wide. The 19 inch dimension includes the edges or ''ears'' that protrude from each side of the ...

, which was common for other systems. Like most computers of the era, the front panel included a number of switches and lamps that could be used to directly set or read the values stored in

main memory Computer data storage or digital data storage is a technology consisting of computer components and recording media that are used to retain digital data. It is a core function and fundamental component of computers. The central processin ...

. A unique feature was a large dial on the right that selected what to display or set, allowing rapid access to the

processor register A processor register is a quickly accessible location available to a computer's processor. Registers usually consist of a small amount of fast storage, although some registers have specific hardware functions, and may be read-only or write-onl ...

s simply by rotating the dial. A key that turned on the power and unlocked the case was positioned on the right side of the case. The system was designed to be highly expandable. A minimal setup consisted of the

central processing unit A central processing unit (CPU), also called a central processor, main processor, or just processor, is the primary Processor (computing), processor in a given computer. Its electronic circuitry executes Instruction (computing), instructions ...

(CPU), a minimum of 4 k 16-bit words of

core memory Core or cores may refer to: Science and technology * Core (anatomy), everything except the appendages * Core (laboratory), a highly specialized shared research resource * Core (manufacturing), used in casting and molding * Core (optical fiber), ...

(4 kW, or 8 kB), and a single

input/output In computing, input/output (I/O, i/o, or informally io or IO) is the communication between an information processing system, such as a computer, and the outside world, such as another computer system, peripherals, or a human operator. Inputs a ...

channel for use with a

computer terminal A computer terminal is an electronic or electromechanical hardware device that can be used for entering data into, and transcribing data from, a computer or a computing system. Most early computers only had a front panel to input or display ...

. The basic system supported vectored interrupts for 32 input/output devices. At the other end of the scale, a maximally expanded system could include up to 4 MB of memory, a

floating point unit A floating-point unit (FPU), numeric processing unit (NPU), colloquially math coprocessor, is a part of a computer system specially designed to carry out operations on floating-point numbers. Typical operations are addition, subtraction, multipli ...

(FPU), multiple multi-line programmable input/output systems, and even more than one CPU. At the maximum, it could support 272 I/O interrupt levels. The expansion system was designed around two external buses, an 8-bit bus for input/output, and a 16-bit bus for memory and storage. Memory modules could hold from 16 to 64 kB per module, available in either 0.7 or 1.5 usec times, with access times about 40% of that due to the read-write nature of core. Store controllers were smart, buffered devices that could control up to eight

disk drive Disc or disk may refer to: * Disk (mathematics), a two dimensional shape, the interior of a circle * Disk storage * Optical disc * Floppy disk Music * Disc (band), an American experimental music band * ''Disk'' (album), a 1995 EP by Moby Other ...

s or

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 magnetic ...

units that loaded and saved bulk data. The controller performed the entire transfer in a manner similar to a DMA controller, raising the appropriate interrupt when the operation was completed. The I/O modules were for slower devices like terminals,

punch tape file:PaperTapes-5and8Hole.jpg, Five- and eight-hole wide punched paper tape file:Harwell-dekatron-witch-10.jpg, Paper tape reader on the Harwell computer with a small piece of five-hole tape connected in a circle – creating a physical program ...

readers and

computer printer A printer is a peripheral machine which makes a durable representation of graphics or text, usually on paper. While most output is human-readable, bar code printers are an example of an expanded use for printers. Different types of printer ...

s that were primarily character oriented. Both could also have

multiplexer In electronics, a multiplexer (or mux; spelled sometimes as multiplexor), also known as a data selector, is a device that selects between several Analog signal, analog or Digital signal (electronics), digital input signals and forwards the sel ...

s for custom connections. Because the buses are not terminated on the CPU, it was also possible to connect several CPU modules to the various modules on the same bus, sharing devices like drives and printers across multiple machines. The K-202 was capable of running about one million operations per second; however, its instruction set was not well suited to the typical tasks, making practical performance somewhat lower. In order to reach this level of performance in a physically small machine, the design made use of

integrated circuit An integrated circuit (IC), also known as a microchip or simply chip, is a set of electronic circuits, consisting of various electronic components (such as transistors, resistors, and capacitors) and their interconnections. These components a ...

s, which were not available in the required density from

Warsaw Pact The Warsaw Pact (WP), formally the Treaty of Friendship, Co-operation and Mutual Assistance (TFCMA), was a Collective security#Collective defense, collective defense treaty signed in Warsaw, Polish People's Republic, Poland, between the Sovi ...

countries. The required components were sourced from the west through the UK partners. The K-202 claimed to be the first mini-computer which used the

paging In computer operating systems, memory paging is a memory management scheme that allows the physical Computer memory, memory used by a program to be non-contiguous. This also helps avoid the problem of memory fragmentation and requiring compact ...

technique, providing 8 MB of virtual memory; however, what its constructors called paging was actually

segmented memory Memory segmentation is an operating system memory management technique of dividing a computer's primary memory into segments or sections. In a computer system using segmentation, a reference to a memory location includes a value that identifies a ...

,. Furthermore, the advertised upper limit of 8 MB of memory was practically unreachable due to signal propagation delays, 144 KB being the largest available configuration. K-202 was based on small- and medium-scale integrated circuits. * Multiprogramming * Multiprocessing * 16-bit word * More than 90 instructions * 7 universal registers * 16 ways of determining argument * Operating memory of up to 4 million words * Direct addressing of up to 64k words * Autonomic data exchange with operating memories at the speed of 16 Mbit/s ote: i.e. 1M words/s* Implementation method – TTL/MSI integrated circuits * Memory cycle 0.7 μs * Processing speed of 1 million operations/second

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Citations

Bibliography

* * {{cite magazine , title=The Computer Genius the Communists Couldn't Stand , first=Marek , last=Kepa , date=7 August 2017 , magazine=Culture.pl

Description

Notes

References

Citations

Bibliography

Further reading