Ural-1

The computer was developed in 1954 - 55 , the first sample was created at the same time (in 1955) at the Moscow plant of calculating and analytical machines . The adjustment was carried out by SKB-245 . The partially adjusted machine was sent to the Penza branch (the future Penza scientific research institute of mathematical machines ). There, from 1957 to 1961 , mass production was carried out. A total of 183 cars were produced. One of the machines was used at the Baikonur cosmodrome for calculating the missile flight ^[5] .

Chief Designer - Bashir Iskandarovich Rameyev , developers: V. S. Antonov, A. G. Kalmykov, A. I. Lazarev, V. I. Mukhin, A. N. Nevsky, A. I. Pavlov, D. I. Yuditsky ^[five]

Lamps in the panel

With a footprint of 70-80 m², the car contained 1000 lamps (mostly 6Н8 ) and diode-resistor valves, consumed 7-10 kW of power.

Most of the instructions were executed in two cycles, but the machine implemented a mechanism for combining the two instructions execution time ^[6] , which was essentially a two-stage conveyor , so the actual speed approached 100 fixed-point operations per second ( division operation was performed four times, and normalization is two times slower).

The capacity of the RAM was 1024 full machine words (which were called “codes” in the 1960s), or about 4.5 KB. RAM was implemented on magnetic drums (100 revolutions per second). The size of the memory cell (36 or 18 bits) was determined by the address - the same place on the magnetic drum could be read as a 36-bit number, as well as any of the two 18-bit ones. The access time to a machine word in memory took 1 clock (in some “unsuccessful” cases, 2). The sequential read speed was 75 codes / sec. ^[1] .

A punch was used for I / O. A blackened film was used as a punched tape. The input speed was 3600 baud (100 words per second) output - 5600 baud (150 words per minute). The control panel consisted of indicators showing in binary code the value of the registers of the control units and the ALU (the machine did not have a processor as a separate device), allowing the operator to set the values ​​of these registers and debug using several keys and toggle switches. The data in memory was saved when the machine was turned off writing to paper or printing out the values ​​of registers and entering them after switching on, it was possible to continue the calculations from the place of interruption. The machine could also carry out digital output to a printing device (100 machine words per minute). Ural-1 also had a tape drive with a reading speed of 75 words per second (2700 baud), a writing speed of 150 words per minute. The data on the film was stored in the form of zones (two zones parallel to each other), which were separated from each other by perforation (on a magnetic film). Given that the film was slower than a punched tape , it provided a larger capacity (40,000 words, that is, 180kB) ^[1] .

When constructing subsequent models ( Ural-2 , Ural-3 , Ural-4 ), partial software and hardware compatibility with the Ural-1 model was retained. ^[five]

• Arithmetic unit (AU); registers AU, private, input and output register.
• Control unit (CU); command counter register, command register, cycle counter register
• Random Access Memory
• Magnetic tape drive
• Input and output devices

Arithmetic and registers

The Arithmetic unit (AU) consists of the following main blocks:

• CM 37-bit binary adder (designation in the formulas of operations - s ), working in the reverse modified code;
• DSM additional 6-bit adder;
• RSAU 36-bit register AU (designation in the formulas of operations - r ), used as an auxiliary when performing operations on codes in the AU, for receiving the code number from the input register, working in the direct code;
• DRG additional 6-bit register;
• RGM 9-bit multiplier register;
• MSS A 36-bit private register used for division.
• The input and output registers have 9 bits each and are used to exchange codes between the AU and other devices (RAM, tape drives);
• Pr code converters;
• Blocks generating control signals ω and φ.

Random Access Memory

The random access memory (RAM) is made on a magnetic drum (called an “magnetic drum drum” NMB) consists of 2048 incomplete cells, with a capacity of 18 bits. Cells are numbered from 0000 ₈ to 3777 ₈ (octal number system). Two adjacent incomplete cells can be combined to create one complete 36-bit cell. Full cells are numbered (octal numbers): 4000 ₈ + n (where n is the number of the first incomplete cell used to store the full cell). Full cells have addresses from 4000 ₈ to 7776 ₈ (in steps of 2, that is, 4000 ₈ , 4002 ₈ , 4004 ₈ ...).

Control Device

The control unit (CU) contains:

• Register-counter team numbers (C, "team counter"), 11 bits. It is used to specify the number of the RAM cell, from which the command is sampled to the command adder register.
• Register-adder commands ("command register"), 18 bits. It is a cyclical transfer adder (from the highest to the lowest). Used for sampling from RAM, changing and storing the next command (performed by a special operation or by the forwarding counter)
• Register-counter forwarding (F, "loop counter"), 11 bits. It is used to automatically change the address of the command being executed (the change is controlled by the trigger f , which is part of the CU).

Remote Control

The control panel consists of signal and command parts. Signal is a series of indicators (neon bulbs) that display the contents of the AU register, control register, command register, command counter register, signals φ and ω, and others.

The control part contains:

• Toggle switches that allow you to specify the value of the memory cell, which are displayed in the control register window (and updated every clock)
• Two toggle switches: Block φ and Stop by φ , which allow you to debug the program being executed. When the “Lock φ” switch is on, the next command is executed regardless of the value of φ and the position of the switch “Stop by φ”. For φ = 1 and the “Lock φ” and “Stop by φ” toggle switches turned off, the next command is skipped (in early instances, control was transferred to cell 0001 ₈ ). If the lock toggle is turned off and the stop toggle is turned on, then after the execution of the next command, a stop occurs.
• Seven toggle switches for controlling key transition commands (θ = 23)
• Two buttons "Erase", which, when pressed simultaneously, resets all 1024 memory cells into RAM.
• The “initial start” button, when clicked, in the cells 0002 ₈ −0010 ₈ reads the contents of zone 0002 ₈ on punched tape and transfers control to the command in cell 0002 ₈ . Zone 0002 ₈ on a punched tape is called the Initial Input Zone .
• Start Button
• Stop Button
• Button "Single-cycle mode", each pressing of which leads to the execution of one (regular) instructions and stop
• Toggle switches to indicate the stop address (the machine stops before executing the instruction before the specified address)
• Two “program print” toggle switches for output (during output, the machine continues to operate, adjusted for the delay of I / O devices):
  • I mode: print program entered in RAM
  • Mode II: printing the address of the command, the type of the command being executed and the contents of the adder register
• Toggle stop machine when referring to the NML, punched tape.
• Keyboard (numeric) for entering numbers into the adder and commands in the command register (for subsequent execution). Input is carried out in octal number system.

I / O devices

Record on a magnetic tape drive (NML) block (zone). The zones are numbered from 0000 to 0177 ₈ and from 1000 ₈ to 1177 ₈ (a total of 256 zones). The size of the zone is arbitrary, it can reach the size of RAM (1024 36-bit codes).

Physically, on the tape, the zones of the range 0000-0177 ₈ and the range 1000 ₈ −1777 ₈ are arranged in pairs (the first zone to the left, the second to the right of the tape width). The marking of the tape is carried out by perforation. The tape moves in one direction, the maximum length of the tape is 300 m. The search time of the zone is up to 5 minutes.

Perforated tape (blackened film) is used to enter, the maximum length of 300 meters. A photoelectric reader is used for reading (speed up to 75 codes per second). Reading is done in blocks (zones), zone numbers from 0000 to 0177 ₈ . The maximum capacity of the zone is 1024 36-bit codes or 2048 18-bit codes. Reverse motion tape is not provided. Search time up to 2 minutes.

The output is carried out on the printing device or on the punch. Buffer register is used for caching. The output takes place without slowing down the machine when the intervals between the output: 0.64 s when printing, 0.46 s when punching.

Clock frequency (duration of the operating cycle) is determined by the time of rotation of the magnetic drum. The beat is divided into two parts: the first part (0.8 turns of the drum) - reading (or writing - depending on the value of the command register) from / to the RAM of the number with which the operation is performed. At the same time, the command for the next clock is read (according to the register-counter of commands); the second part (0.2 turns of the drum) is the execution of an arithmetic (or other) operation according to the operation code that was before the execution of the clock in the command register. (At this time, the current command is stored in a special five-bit register). During the second half of the clock cycle, the command counter is incremented and redirected to the contents of the redirection register, if the read command contains a redirection sign.

The normalization and division operations take 4 and 2 clocks (magnetic disk rotation). During these cycles, the selection of commands is not performed.

If the executive address of the command ã is in the interval from C to C + 64 (C is the register-counter of commands), the execution time of the instruction may increase by 1 clock cycle.

Ural-1 supports 29 different instructions (35, including 6 instructions that do not do anything, analogous to the modern NOP ). A significant difference from the modern architecture of computers is the equality of operations with registers, RAM, and I / O devices.

Arithmetic commands: write to register, add, add, overflow, subtraction, modulus difference, two types of multiplication, division, sign change, left shift and right (one command, the direction of the shift is determined by the flag), bitwise multiplication (conjunction), bitwise addition (disjunction), comparison, normalization of representation

Control commands: write to memory, write to register, write address to adder, conditional go, unconditional go, key select operation (close analogue of case in C), loop command, program code change command, stop command

I / O commands: data exchange from punched tape (or magnetic tape) and RAM, read command from punched tape, writing to punched tape, outputting the contents of the adder on a puncher, the “run” punched tape command.

Ural-1 machines were used for engineering and economic calculations. In particular, Ural-1 was used to calculate the flight of rockets at Baikonur , to simulate the learning process associated with the process of creativity. ^[7] .

Computers Ural-1 were used in schools. For example, in the mid-1960s. such a machine was transferred to the 30th Mathematical School of Leningrad . ^[8] . The Ural-1 computer was also used as an educational program at the 239th Physics and Mathematics School of Leningrad before moving to a new building in 1975, where it was replaced with the Minsk-22 computer and, unfortunately, was not preserved. In 1965, the machine of Saratov State University (serial number within the top ten) after the cancellation was transferred to secondary school No. 13 ^[9] (now Physical-Technical Lyceum No. 1) and used to teach pupils programming. Subsequently, it was expanded to Ural-3, and then replaced by the 2nd generation computer (BESM). Unfortunately, the "Ural" was not accepted for storage by the local history museum, and therefore dismantled.

• V. Bondarenko, I. T. Plotnikov, P. P. Polozov , Programming tasks for the Ural machine, Izd. Art. Ing. Academy. Dzerzhinsky, 1957
• Kitov A. I. , Electronic digital machines, “Soviet Radio”, 1956
• Kitov A.I., Krinitsky N.A. , Electronic digital machines and programming, ed. second, Fizmatgiz, 1961
• Zhdanyuk B.F. , Quick Guide to the work behind the control panel of the computer "Ural", Moscow, 1961 ;
• Burakov M. V. Experience of operation of the digital computer "Ural". M., 1962;
• "Ural-1" - the first Soviet serial computer

• N. Ya. Smolnikov , Fundamentals of Programming for a Digital Machine Ural , Sovetskoye Radio, 1961;
• B.F. Zhdanyuk Quick Guide to the control of the computer "Ural" , Moscow, Publishing 1961
• N. A. Krinitsky, G. A. Mironov, G. D. Frolov , Programming, ed. M. R. Shura-Bura, State Publishing House for Physics and Mathematics, Moscow, 1963 (Chapter 9)
• Sergey Tarkhov. "Ural" (rus.) . Museum of the history of domestic computers . The appeal date is October 29, 2012. Archived November 20, 2012.
• About the Ural-1 computer (inaccessible link from 05-10-2013 [2120 days )]
• SE Khusid, Itskovich IA, IS Litvak and IM Lobov for Measurement Techniques, New York, 1972 (Translated from Journal of Measuring Technology, No. 3, 1965
• Fragments of the book by G. S. Smirnov “The Ural computer family”. Pages of the history of development. "
• G.S. Smirnov. Ferrite memory computer "Ural"
• Electronic digital computer "Ural-1" (digital computer "Ural-1")
• Rameevskaya School of Computer Design. The history of developments in photographs 1948-1972
• B.I. Rameev. Universal automatic digital machine like "Ural" , conference materials "Ways of development of the Soviet engineering and instrument-making" conference, Moscow 1956

emural - developed emulator of Ural family