CER ( – ''Digital Electronic Computer'') model 12 was a third-generation digital computer developed by

Mihajlo Pupin Institute Mihajlo Pupin Institute ( sr, Институт Михајло Пупин, Institut Mihajlo Pupin) is an institute based in Belgrade, Serbia. It is named after Mihajlo Idvorski Pupin and is part of the University of Belgrade. It is notable for ma ...

( Serbia) in 1971 and intended for "business and statistical data processing" (see ref. Lit. #1 and #4). However, the manufacturer also stated, at the time, that having in mind its architecture and performance, it can also be used successfully in solving "wide array of scientific and technical issues" (ref. Lit.#2 and #3). Computer CER-12 consisted of multiple modules connected via

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 ...

and connectors.

Central Unit

Primary memory * Type:

magnetic core A magnetic core is a piece of magnetic material with a high magnetic permeability used to confine and guide magnetic fields in electrical, electromechanical and magnetic devices such as electromagnets, transformers, electric motors, generators, in ...

memory * Capacity: up to 8 modules, each consisting of 8

kiloword 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 s ...

s (1 word = 4 8- bit bytes). * Speed: cycle time: 1

μs A microsecond is a unit of time in the International System of Units (SI) equal to one millionth (0.000001 or 10−6 or ) of a second. Its symbol is μs, sometimes simplified to us when Unicode is not available. A microsecond is equal to 1000 ...

, access time 0.4

. Arithmetic unit contains: * 32- bit accumulator register * two separate groups of eight 2- byte index registers * single-byte

adder Adder may refer to: * AA-12 Adder, a Russian air-to-air missile * Adder (electronics), an electronic circuit designed to do addition * Adder Technology, a manufacturing company * Armstrong Siddeley Adder, a late 1940s British turbojet engine * ''B ...

supporting both binary and BCD addition (same unit is used for

subtraction Subtraction is an arithmetic operation that represents the operation of removing objects from a collection. Subtraction is signified by the minus sign, . For example, in the adjacent picture, there are peaches—meaning 5 peaches with 2 taken ...

multiplication Multiplication (often denoted by the cross symbol , by the mid-line dot operator , by juxtaposition, or, on computers, by an asterisk ) is one of the four elementary mathematical operations of arithmetic, with the other ones being additi ...

and division had to be implemented in software) Control Unit Control unit contains a

program counter The program counter (PC), commonly called the instruction pointer (IP) in Intel x86 and Itanium microprocessors, and sometimes called the instruction address register (IAR), the instruction counter, or just part of the instruction sequencer, is ...

and instruction registers. It fetches instructions and facilitates program flow. It supports single-operand instruction set and works with all 16 index registers of the arithmetic unit. Interrupt System Interrupt system of CER-12 consists of a number of dedicated registers and software. It supports up to 32 interrupt channels. Control Panel Control panel of CER-12 allowed the operator to control and alter program flow and/or to eliminate errors detected by error-detection circuitry. It features a number of indicators and switches.

Operating system and other software

Following software was shipped with CER-12: * Operating System * "Symbolic programming language" and assembler (called "autocoder") * Input/output subroutines * A number of test programs *

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 ...

and FORTRAN IV compilers *

Linear programming Linear programming (LP), also called linear optimization, is a method to achieve the best outcome (such as maximum profit or lowest cost) in a mathematical model whose requirements are represented by linear function#As a polynomial function, li ...

and PERT planning software * A library of applications and subroutines

Peripherals

* 5-8 track, 500 characters per

second The second (symbol: s) is the unit of time in the International System of Units (SI), historically defined as of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds ...

punched tape reader PE 1001 * 5-8 track, 150 characters per

tape puncher PE 1501 * CDC 9432 magnetic disk drive as

secondary storage Computer 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 processing unit (CPU) of a computer ...

(4,096,000 characters per 6-disk, 10-surface volume organized into 100 cylinders with sixteen 1536- bit (48 processor words) sectors; track-to-track seek: 30 ms; rotational latency: 25 ms) * IBM 1735 teleprinter * ICL 667 line printer (725 lines per

minute The minute is a unit of time usually equal to (the first sexagesimal fraction) of an hour, or 60 seconds. In the UTC time standard, a minute on rare occasions has 61 seconds, a consequence of leap seconds (there is a provision to insert a nega ...

for 64-character set or 880 lines per minute for 50-character set)

Literature

# Vladislav Paunović: Arithmetic unit of the CER-12 computer, AUTOMATIKA, No 3, pp. 161–165, Zagreb 1971. # Veselin Potić, Mihael Šavikin, I/O system of the CER-12 computer, AUTOMATIKA,No 3, pp. 166–176, Zagreb 1971. # V Batanović, J.Kon (Ed): IMP Riznica znanja, pp. 5–8, M.Pupin Institute and PKS, Belgrade 2006. (in Serbian) # Dušan Hristović: Development of the Computing Technology in Serbia (Razvoj Računarstva u Srbiji), PHLOGISTON journal, No 18-19, pp.89-105, Museum MNT, Belgrade 2010/2011, In Serbian. {{DEFAULTSORT:Cer-12 Mihajlo Pupin Institute CER computers One-of-a-kind computers

Central Unit

Operating system and other software

Peripherals

See also

Literature