ASCII History

You may not believe this, but the ASCII character set is one of the greatest inventions ever in the history of computer science. If you’re a millennial (I am too – just forty or so years late), you may not even know the history and benefits brought about by this technology. And yes, it is a technology.

In the early days of computers, there were literally dozens if not a hundred ways to represent letters and numbers in computer memory. Part of the reason for this was that the size of a single element of computer memory didn’t get standardized until the late 1950s and ’60s. A single addressable element of computer memory varied with the hardware and was a small as a single bit and as large as a 48 bits.

An interesting tidbit almost lost to history is that an engineer at IBM coined the term “byte” to represent the set of bits that comprised a character. Prior to that, the set of bits comprising a character was variable. IBM computers of that era had variable sized memory and instructions. A name was needed for the set of elements that comprised a single character. They choose the term “byte”, a deliberate misspelling of “bite,” so as to not confuse the terms bite and bit.

Bytes in those early days were generally six bits. All of the early card punches used six bits to encode character data. With the IBM 360 line, this was expanded to eight bits to accommodate an expanded character set. IBM called this expanded character set the Extended Binary Coded Decimal Interchange Code (EBCDIC). But EBCDIC was only one of many codes. The military used a different coding set. AT&T which, at that time, ran all telephone operations in the entire country, had something else. Other IBM competitors invented their own. It was a mess as you might imagine.

In 1961, IBM engineers led the effort to get the American National Standards Institute (ANSI) to develop a single common code for communications. That effort led to ASCII – the American Standard Code for Information Interchange. In 1968 President Lyndon Johnson signed a memorandum adopting ASCII as the standard for federal computers, but it wasn’t until Intel invented eight-bit microprocessors in the early ’70s that eight bits and ASCII became common. Even in the late ’70s, IBM 360 computers – what every Fortune 500 company used – were using the old EBCDIC standard. EBCDIC was finally retired with the introduction of the personal computer in 1981.

Today with Internet communication, it is hard to understand how difficult it was to move data between computers. Not only did you not have a hardware mechanism to move data – you had no common data format. Realize that it wasn’t until 1981 that the UART (universal asynchronous receiver/transmitter) was invented. There literally was no standard mechanism to move data. And if you could physically move it, the data would be in an incompatible format and you’d have to write a program to convert it. Unless the computers were from the same manufacturer, data didn’t move. At all!

But that’s history. ASCII is with us today and will be with us forever – especially for us in Industrial Automation. We will always need to print things. We will always need to read simple ASCII barcodes. We will always have product, device, and location descriptions and much more. And there is little need to replace it. There are ways to compress those data strings – they do take time to process and to transmit, but as time goes on and our networks get faster, the verbosity of ASCII will become less troublesome.

At RTA, we are the kings of moving ASCII data around the factory floor. We have products to move ASCII data over Modbus, ASCII data over Modbus TCP, ASCII data over DeviceNet, ASCII data over EtherNet/IP, and ASCII data over Profinet IO. We can move ASCII data into ControlLogix PLCs. Control engineers use our products to move ASCII data into Siemens PLCs and read and write ASCII from Modicon controllers.

We’ve always recognized that moving ASCII data is a key component of how you need to move data around the factory floor, and we’re committed to providing the products that you need to do it.

Please contact us or call (262-436-9299) and one of our inside sales technicians with any questions on moving your ASCII data around your factory. They’ll be happy to hear from you.