# Electronic Digital Computer Ural-11 (Урал-11)

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Ivan Vasilyevich Urnev

**Computer Ural-11**

- Chief designer –
**B.I. Rameev***(**Rameev Bashir Iskanderovich*).

Leading assistant designers: V.I. Burkov, A.N. Nevsky, A.G. Kalmykov, V.I. Mukhin, G.S. Smirnov, A.S. Gorshkov. Leading designers: L.N. Bogoslovsky, V.K. Eliseev, V.G. Zhelnov, M.N. Knyazev, O.F. Lobov, A.I. Pletmintsev, Y.V. Pinigin and others.

- Basic organisation in charge of the project and design: Penza Scientific-Research Institute of Electronic Computing Machines.
- Producing plant: Penza Plant of Computing Analytic Machines (under MIAM USSR).
- Completion of design (year): 1965.
- Beginning of serial production (year): 1965.
- Finishing of serial production (year): 1975.
- Application field: computations for expanded field of mathematic problems and operation at computer centres of scientific research institutes, design bureaus and industrial enterprises.
- Number of produced computers: 123 pieces.

## Description

(structure, architecture and peripheral devices of the computer)

Computer URAL-11 was the first one of a new line, which also included URAL-14 and URAL-16. Computers of the URAL line had unified basic design, manufacturing technologies and components. All three models had the same input\output and storage devices, implemented the same input\output alphabet and the same codes on punched cards, magnetic tapes and internal computer codes.

URAL-11 processed numbers with both fixed and floating point and also alphanumeric symbols. Addressed word was 24 bit long. Its one-address command system was the same as in other computers of the line. Binary and –combined- binary-decimal arithmetic. RAM capacity varied from 8192 to 16 384 words of 24-places.

Central processor unit of URAL-11 consisted of arithmetic and control unit — U-328, performing and supporting all arithmetic and logic operations with 24-place numbers. Its performance equaled 50000 short operations and 350 multiplications per second. Multiplication and operations with binary-decimal numbers were accelerated with the use of single, autonomous devices for multiplication (U-340) and summing for binary-decimal numbers (U-342). Those devices increased multiplication performance up to 14 000 ops and addition (subtraction) of the binary-decimal numbers to 5000 ops with 11-bit (place) numbers. Besides that, a special arithmetic device (U-345) was created for 48-bit numbers. Six various modifications of URAL-11 were manufactured (differences depended on the given set of arithmetic devices, RAM devices and peripheral set). They were equipped with memory on magnetic tape and drums, punched tape and punched card devices and alphanumeric printers.

## Components

Computers URAL-11 — URAL-16 were based on *unified complex of logical components* – “URAL-10”. Those were semiconductor circuits-modules. There were 5 types of the basic (standard) and 10 types of specialised modules (for memory storage and peripheral devices). Electronic circuits of URAL-11 consisted -for 90%- of basic diode-transistor modules of two types, which could stably function within temperature range: -10°С to +70°С. The modules were mounted in cells, which had plug-and-socket connectors with soldered contacts.

## Design

Computers URAL-11 — URAL-16 were produced with standard design. Electronic components were mounted in standard cabinets. The boards with mounted cells containing diode and transistor components were placed in the cabinets.

All boards had printed wiring and connections. Computer URAL-11 the “junior” model of the line had a console design. All storages and peripheral devices were of the same type in all URAL computers.## Assembly technologies

Traditional technologies of mechanic and plastic parts processing were implemented. Cabinet frames were welded. Cells and modules with printed wiring were made of foiled dielectric. Their serial production was performed at special plant. Manufacturing technology of ferrite memory storage and peripheral devices, as well as of magnetic tape memory and alphanumeric printers, was new for the Penza plant.

## Software

Dispatcher-program was the basic one for organisation of the computer operation. It provided input\output of information, organised operation in multi-program mode, protected RAM zones, supported dynamic distribution of RAM resources and also of external memory on magnetic drums and tapes.

The computer was also provided with special automatic code ARMU (Russ. abbr. for *A**utomatic*-code* Row* (line) of

*M**achines*(URAL computers)). That was a unified auto-code for all URAL computers line. It was composed upon consideration of their specific features and fully maintained compatibility of junior models to senior ones. However, each model of URAL had its own translator from ARMU language to its internal machine language, therefore compatibility of the URAL computers remained limited and existed only on the ARMU auto-code level.

**U**RAL## Main operation and technical data of URAL-11

- Length of the addressed word in RAM -12 or 24 bit
- Number of places in numbers:
- With fixed point – 12, 24, 48 bit
- With floating point – mantissa – 39 bit, places — 7
- Decimal – 3 places and more
- Arithmetic – binary and decimal
- System of commands – one-address
- Number of instructions – 150
- Index registers – 7 in 30
- Interruption channels – 30
- Interruption levels – 30
- Operation performing times,
*microseconds* - Logical addition (24 places) – 20
- Logical addition (48 places) – 40 (with U-345)
- Digital addition (5 digits) – 80(with U-342)
- Addition with floating point (39+7) – 40 (with U-345)
- multiplication (24 places) – 70 (with U-340)
- multiplication (48 places) – 100 (with U-345)
- multiplication with floating point – 100 (with U-345)
- Capacity of storages in the words of 24+2 bits
- ferrite 8192 – 16384
- magnetic drums 98 444-787 552
- magnetic tapes 1 000 000 — 48 000 000
- Speed of information exchange between RAM and the following devices (
*bit per second*): - Magnetic drum storage – up to 500 000
- Magnetic tape storage – from 130 000 to 700 000
- Maximum speed – 2 200 000
- Information input\output speed:
- Punched tapes – 1000 lines
*,*from a device - Punched cards – 700 cards a min
*,*from a device - Communication channels – up to 2 200 000 bit/sec
- Information output speed:
- To printer – 400 lines a min (one device)
- To punched cards – 110 cards/min.
- To punched tape – 80 lines/sec.
- Communication channels – 2 200 000 bit/sec.
- Conditions of operation:
- Environment temperature: – 5°С to 40°С
- Humidity conditions – 65(±15%)

## Specific features of the computer

URAL-11 – the first computer of URAL line, designed/manufactured on unified design and technology basis of URAL-10. That was the USSR first experience in designing a family of compatible computers, instead of a single machine. Design and technological unity of computers and their devices was the focus point of the inventor’s (B.I. Rameev) attention. However, implementation of special devices for multiplication, decimal arithmetic and operations with floating point essentially increased price of computer URAL-11.

Translated by A. Nitussov