The COBOL Programming Language

The COBOL Language

Pedro Trebbau Lopez

The COBOL programming language was created in 1959 with the goal of having a universal programming language that could be used on any computer, because in the 1960s there were numerous incompatible models of computer. COBOL was mainly business oriented. COBOL is the acronym of Common Business-Oriented Language.

In creating this language, the CODASYL committee participated. CODASYL was made up by computer manufacturers, users and the Department of Defense of the United States in May 1959. The definition of the language was completed in just over six months, and was approved by the commission in January 1960. The COBOL language was designed and inspired by the Flow-Matic language designed by Grace Hopper and Bob Bemer’s COMTRAN, owned by IBM. Hopper and Bemer were both part of the commission.

With the help of COBOL users, it quickly evolved and was revised in 1961 to 1965 to add new functionality. In 1968 came the first ANSI version of the language, and was later revised in 1974, 1985 and was expanded in 1989 with mathematical functions, giving an end to the current most widely standard used, known as COBOL ANSI and 2002 ANS -2002 COBOL.

There is a version known as COBOL ENTERPRISE released in 1991 and regularly updated, generally used in servers.

Minicomputers: The IBM System/34

IBM System 34

Pedro Trebbau Lopez

The System/34 also known as S/34 was a minicomputer manufactured by  IBM. It was introduced in April 1977 as a cheap alternative to the mainframes of the S/370 series . It was the successor to the System/32 and System/36 and the precursor of the smaller sister S/38 system . The S/34 served as a multi-user computer for departments and small businesses and was produced until February 1985.

The memory capacity was a maximum of 256 kilobytes of RAM . The S/34 could be operated in the basic setup of two and, by a extension through a special module, four disk drives, each with 64 megabytes. It was required to operate with a connected and ready for operation chain printer, which worked as a system main printer. Its absence made ​​the operation of the S/34 not impossible, but it caused an starting error when booting the machine. The backup was made exclusively via 8″ floppy disks. Depending on the version of S/34, there were three individual feeds and two additional slots for magazines with ten floppy disks.

A maximum of 14 terminals could be connected to the system. The terminals used were the 5250. A total of 7 terminals could be connected serially, one after another. To achieve this, each terminal had an input and output connector. The terminal on the first position with a logical o/o address was the control or system console. The operators and administrators could get there  the error messages from the SSP operating system an do the general operation of the computer.

IBM System 3: Predecessor of the Modern Server

IBM System 3

Pedro Trebbau Lopez

The IBM System/3, introduced in 1969 and discontinued in 1985, was a cheap IBM computer for office tasks aimed at new customers or organizations that still maintained computers or IBM accounting machines of the 1400 Series. It was the first member of the family that IBM called Midrange. These computers are known currently as minicomputers and servers.

It implemented a new punch card format that stored 96 characters. Instead of the classic rectangular perforations of IBM cards the new card had small holes 1 mm in diameter, similar to those that a punched tape had. The data were stored in six-bit BCD format, with columns of 32 characters each, or eight bits in EBCDIC format with two additional holes located at the bottom of the columns.

The cards held 128 characters printed in 4 columns of 32 characters each. The IBM System/370, with an appropriate card reader, could also process the new cards.

Many units of the System/3 Model 10 were sent only with the original I/O punch card (reading, punch and management ) and a printer. There were two card reader models . The most common was known as MFCU or Multifunction Card Unit which read, punched and sorted new cards of 96 columns. The second model, less common, was the MFCM or Multifunction Card Machine, performing the same operations, but only with the most common cards of 80 columns. The MFCM was provided to large companies that already had equipment for 80-column cards . There were 3 models of different speeds: 100ppm , 200ppm and 300ppm . The printers were offered in several model.

What is Ruby on Rails

Pedro Trebbau Lopez – Ruby on Rails

Pedro Trebbau Lopez

Ruby on Rails , also called RoR or Rails is a open source web application framework  written in the Ruby programming language, following the paradigm of Model View Controller (MVC) architecture. It tries to combine simplicity with the opportunity to develop real-world applications writing less code than other frameworks and with a minimum of configuration. The Ruby programming language allows metaprogramming, which Rails uses, resulting in a syntax that many of its users consider very legible. Rails is distributed through RubyGems , which is the official packet format and distribution channel for Ruby libraries and applications.

The fundamental principles of Ruby on Rails include Don’t Repeat Yourself paradigm or DRY and Convention over Configuration .

Don’t Repeat yourself means that the definitions should be done only once. Since Ruby on Rails is a full stack framework, components are integrated so you do not need to build bridges between them. For example, ActiveRecord definitions of classes don’t need to  specify the names of the columns. Ruby may inquire from the database itself, so that define them both in the code and the program would be redundant.

Convention over configuration means that the programmer only needs to define the configuration that is unconventional. For example, if there is a History class in the model, the corresponding table in the database is stories, but if the table does not follow the convention, for example blogposts, it must be manually specified. So, when designing an application from scratch with no pre-existing database, following the conventions of Rails means using less code, although the behavior  of the application can be set whether the system should be compatible with a previous system.

The MiniDisc

Pedro Trebbau Lopez – A MiniDisc player

Pedro Trebbau Lopez

The MiniDisc or MD minidisk is a magneto-optical digital disc developed in the 90s by  Sony. It is  smaller than a conventional CD and has an increased capacity compared with it. The Japanese company wanted to move on with its flagship device, which was released in Japan in January 1992 as an attempt to replace the tape cassette. Sony  has announced that it will stop the distribution of the device from March 2013 on, due to its low demand .

Punched Tape

Pedro Trebbau Lopez – Punched Tape

Pedro Trebbau Lopez

The punched  tape is an obsolete data storage method  that consisted of a long strip of paper in which holes were made to store the data. It was much used during a big part of the twentieth century for communications with teletypes, and later as a data storage medium for minicomputers.

Punched Cards

Pedro Trebbau Lopez – A punched card

Pedro Trebbau Lopez

The punched cards is made ​​of cardboard sheet containing information in the form of perforations in a binary code. These were the first methods used to enter data and instructions into a computer in the 1960s and 1970s. Punch cards were used previously by Joseph Marie Jacquard  in his invention, the automated loom. They were then used in  the first electronic computers by companies such as IBM, NCR, Burroughs and others.

Learn more here. 

Tape Units

Pedro Trebbau Lopez – Tape unit

Pedro Trebbau Lopez

A tape drive  or streamer is a device for storing data on magnetic tape. At the beginning of the computer age in the 1950s and 60s the image of the two spools of tape came to symbolize the typical image of the computer itself.

The Datasette was in the transition from the 70s and 80s and related with  the personal computer. In the XXI century certain tape drives are still used for storing large amounts of data as backup.

Learn more here.

Diskettes or Floppy Disks

Pedro Trebbau Lopez – Diskettes

Pedro Trebbau Lopez

A diskette is a flexible plastic disc coated with ferromagnetic particles, which enables the recording, erasing and reading of information on its surface by means of an electromagnetic head. They are protected by a plastic cover that is more rigid to avoid contact with the outside. These disks are of the  portable type and allow the  transference of information from one computer to another. There have been many sizes and capabilities through its evolution. This technology was introduced commercially in computers in 1971 by IBM. The use of floppies, as they are also known, is practically obsolete now.

Learn more here.

The First Macintosh and its launch 30 years ago

Pedro Trebbau Lopez – Apple Macintosh 128k

Pedro Trebbau Lopez

The first Macintosh, the Macintosh 128K, was announced to the press by Apple in October 1983, followed by a dossier of 18 pages included in various magazines in December of that year. On January 24, 1984, the famous TV ad directed by Ridley Scott entitled “1984”  was presented.  The ad was broadcast  in the third quarter of Super Bowl XVIII and its production had  a cost of 1.5 million U.S. dollars. Today, it is considered a masterpiece.

Learn more here.