how do barcodes work?
79969
There are lots of types of barcode, but the common one we all see all the time is called UPC, the Universal Product Code. \n\nEach digit is coded by two black and two white stripes. The stripes have widths of from 1 to 4 units, and the total width for each digit is always seven units.\n\nThis code is not quite all there is to it, however. Some digits of the barcode are reversed, so that they read right to left. Part of the code has black and white inverted, so black stripes are white and vice versa. This helps cut down errors and allows a computer to work out if the code was read from the wrong end when it was scanned.
1122101
I think maybe the production company should be helping you with that. I found this site though... maybe it will help you.\nhttp://www.java4less.com/barcodes_dotnet.html
817668
The magnetic stripe is encoded with the card number; there is also other informtion encoded as well, which may include any limit the bank places upon purchases with the card, and the card's expiration date.  The encoding itself isn't too different from the encoding used on old-fashioned tape drives that computers relied upon before disks.  The card reader gathers this information when you swipe it through on an ATM machine, gas pump, or similar device, then "talks" with the appropriate bank to make sure that the customer is not over their credit limit, or that the card is still valid and has not been lost or stolen.  If everything checks out, the transaction goes through, and you get your cash, or gas, or purchase.
338543
It's not really controlled until you get caught or use a color laser printer.  Laser printers embed codes into whatever they print.  You can find them pretty easily with a microscope and different colored light filters.
315031
http://www.milk.com/barcode/\n\nhttp://www.taltech.com/TALtech_web/resources/intro_to_bc/bcpwork.htm\n\nhttp://www.codeproject.com/dotnet/barcodeImaging.asp
1049597
it is a braille typewriter with 6 keys that when combined in to different combinations make braille dots which the blind/visually impaired can used to write. there is also something called a "braille note" which if hooked up to a computer can print what ever the blind person has typed in either in braille (for themselves/others with blindness) or standard print for any sighted person who needs to read what the blind person wrote.but doesn't know the braille alphabet.
383086
There is no particularly deep relationship.  Keys on the keyboard are mapped to a scan code which is converted by the operating system to an ASCII (or unicode or whatever high-level encoding scheme is being used) for a program to render as text.  So...\n\nKeyboard input --> Scan code --> Computer --> ASCII/Unicode/Whatever encoding --> Software Program --> Converts ASCII value into a human-readable character in a particular font.\n\nI hope that helps a bit.
340225
postnet is the barcode used on Mail , it is a barcode and is used mainly by direct mail houses. here is a page that does give some information on it \nhttp://www.idautomation.com/fonts/postnet/
1158367
Here is a link to the Wikipedia page on Code 39, also known as "3 of 9" barcode.\nhttp://en.wikipedia.org/wiki/Code_39\n\n"Code 39 is a barcode symbology that can encode uppercase letters (A through Z), digits (0 through 9) and a handful of special characters like the $ sign."\n\nFrom the above web page, some links to free barcode fonts.\nhttp://www.barcodesinc.com/free-barcode-font/\nhttp://grandzebu.net/informatique/codbar-en/code39.htm\n\nHere is an online barcode generator.\nhttp://www.barcodesinc.com/generator/
182795
Scanners built into the vending machine scan the money into memory which compares it against images that are stored onto the firm wear.  That is why most vending machines require money be inserted in a certain fashion.  The scanner checks both top and bottom of the currency as well as the transparency of the material to make sure it is printed on the correct medium.  There are also some proprietary technology that is used to verify that it is proper currency.
1029934
The USPS does not recommend putting a barcode on mail that you do not intend to use the automation rate, because it will not speed up your mail and if used incorrectly, will actually slow delivery. This implies that the barcode would be read.
209123
a code(numbers and letters usually) that you get when you book a flight or buy something on line or the phone...something like that.
636390
A linear bar code is a binary code (1s and 0s). The lines and spaces are of varying thicknesses and printed in different combinations. To be scanned, there must be accurate printing and adequate contrast between the bars and spaces. Scanners employ various technologies to "read" codes. The two most common are lasers and cameras. Scanners may be fixed position, like most supermarket checkout scanners, or hand-held devices, often used for the taking of inventories. There should be (but typically is not,) a distinction drawn between the code, which is a structure for the conveyance of data, and the symbol, the machine-readable representation of the code. The code is text, which can be translated into a multiplicity of languages - English, French, Japanese, symbol.\n\nNotwithstanding its inauspicious beginning, the bar code has become a remarkable success, a workhorse in many and varied applications. One of the first successful bar codes, Code 39 developed by Dr. David Allais, is widely used in logistical and defense applications. Code 39 is still in use today, although it is less sophisticated than some of the newer bar codes. Code 128 and Interleaved 2 of 5 are other codes that attained some success in niche markets.
99731
Reading a barcode value always needs a textbox. What is the use of Keypress event... No use.\n\nNormally if you created a textbox and set the focus to it before firing the barcode scanner you'll get the return data in your textbox instantly.
200127
there is no price information encoded in a bar code. When the scanner at the checkout line scans a product, the cash register sends the UPC number to the store's central POS (point of sale) computer to look up the UPC number. The central computer sends back the actual price of the item at that moment. \nThis approach allows the store to change the price whenever it wants, for example to reflect sale prices. If the price were encoded in the bar code, prices could never change. On the other hand, not encoding a fixed price gives the store an easy way to rip off customers. When you hear about "scanner fraud" in the news, that is what the newsperson is talking about. It is incredibly easy for a store to mistakenly or purposefully overprice an item.
408570
Using scanners and barcode readers to read the information off the ticket. Simple really.
375596
http://www.barcodesinc.com/free-barcode-font/\n\nThey have a free code 39 barcode font.