Engineering News Blog

Engineering News

Latest news of interest to engineers. Sourced from GlobalSpec's Engineering News

Previous in Blog: How Hard is the Human Powered Helicopter?   Next in Blog: 19 Patents Invented by Ingenious Celebrities
Close
Close
Close

June 26, 1974: Supermarket Scanner Rings Up Historic Pack of Gum

Posted June 26, 2012 7:46 AM
Pathfinder Tags: June 26

From Wired Top Stories:

A supermarket cashier scans a multipack of chewing gum across a bar-code scanner in Troy, Ohio. It's the first product ever checked out by Universal Product Code.

Read the whole article

Reply

Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".
2
Guru
Engineering Fields - Optical Engineering - Member Engineering Fields - Engineering Physics - Member Engineering Fields - Systems Engineering - Member

Join Date: Apr 2010
Location: Trantor
Posts: 5363
Good Answers: 646
#1

Re: June 26, 1974: Supermarket Scanner Rings Up Historic Pack of Gum

06/26/2012 8:29 AM

The IBM barcode design was really pretty clever. The format, the width of the bars and spaces, took into account the mediocre printing methods available for most food packaging in the mid-70s. It used a proportioning method that allowed the label to be larger for milk cartons and smaller for packages of gum.

The code was designed as two halves, so the scanning system could read half the code, then read the other half, store this information and then de-code the label knowing which half was which by the starting and finishing bars. The code for a given digit was different depending on which side of the label it appeared, left or right, which aided the decoding. And the number included a check-sum digit to help insure accuracy.

The system also allowed a common variant from the 10-digit code that used an 8-digit code known as EAN-8. (This was the code typically used on very small items.)

Probably by now, most people know that the price of an object is not encoded. A product is initially scanned and all of the product information is entered by the store manager into the computer, to be read-out when the object is scanned at the register.

A side note to the story is that although IBM invented the code, RCA's equipment was easily adaptable from the bulls-eye code to the IBM code and actually read the IBM code before IBM's own machine did. The first installation was an RCA system.

Another side note is that RCA's system failed due to bad HeNe lasers. It was the early days of the HeNe and their custom-made lasers kept failing.

__________________
Whiskey, women -- and astrophysics. Because sometimes a problem can't be solved with just whiskey and women.
Reply Good Answer (Score 2)
Reply to Blog Entry
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Previous in Blog: How Hard is the Human Powered Helicopter?   Next in Blog: 19 Patents Invented by Ingenious Celebrities

Advertisement