The Basics Of Bits (Part III)
Computers uses different patterns to represent the number 201 and the text 201. Text is an example of a new building block built on the raw bits. We mentioned earlier this is call encoding. The two most commonly used encoding systems for text are ASCII and the modern Unicode.
In most cases a text has a special character to denote the end of the string. This special character is called null or terminator.
The number of 201 can be represented in a single byte (of type char), but to represent the same number as text requires a total of 4 bytes. The table below depict the ASCII encoding of the text 201 (note the extra terminator character to denote the end of the string):
A big number like 2 billion (2,000,000,000) can fit into a 32 bit integer type (4 bytes), but to represent that same number (including commas) in text format will require a total of 14 bytes (do not forget the terminator)!
char, integer and text are three of the most common data types used by computers. There are more data types together and together we can create very complex software and data files.
For example, a photo viewing software that can load a JPEG encoded file on your computer. The software will be load from the storage medium and be executed by the computer. The execution will include reading another file, encoded in JPEG format, process the file and then display the decoded picture on your computer monitor.
Another example you’d be more familiar with is a music playing software (e.g. MPD, Roon) reading a FLAC, WAV, APE or MP3 file, decode the information within and convert that into music that is played back on your Hifi system.
Computer bits are like the grains of sand, on its own it’s just an unassuming speck. Together the grains of sand can be shaped and sculptured to take on new forms and meaning - a beautiful sand castle.
Sand castle can be washed away with the incoming tide, as bits can erode away over time.
Comment from: Frank Collins Visitor
I don’t believe bit rot is a problem and the Red Book standard copes with missing bits, to a point.
I store all of my music (FLAC, level 8 compression) on a NAS, using FreeNAS. It does a four-weekly scrub which detects and corrects bit rot on the whole file system. While bit rot isn’t a problem for me, it never will be.
It does a four-weekly scrub which detects and corrects bit rot on the whole file system. While bit rot isn’t a problem for me, it never will be.+1. FreeNAS for the win.
A "single-event upset" was also blamed for an electronic voting error in Schaerbeekm, Belgium, back in 2003. A bit flip in the electronic voting machine added 4,096 extra votes to one candidate. The issue was noticed only because the machine gave the candidate more votes than were possible. "This is a really big problem, but it is mostly invisible to the public," said Bharat Bhuva. Bhuva is a member of Vanderbilt University’s Radiation Effects Research Group, established in 1987 to study the effects of radiation on electronic systems.
Here is an interesting YouTube video about bit flipping.