Hexadecimal

Pertaining to a system of numbers to the base 16; hexadecimal digits range from 0 through 9 and A through F, where A represents 10 and F represents 15.

Base 16, also known as Hexadecimal or Hex is a numbering system that has a radix of 16 and therefore a natural encoding for 16-bit systems and processors, and commonly used to represent values for 32, 64 and 128 bit systems as well.

Hex file format
An plain text file that uses hexadecimal values to store machine language code in, it was a common way to store data and executables in the early days of personal computing computing when operating systems were less common than simple loaders and machine code monitors, but in modern day use it is primarily used for files that need to be loaded directly into a memory address such as files to be loaded into microcontrollers, firmware files and so on.

By far the most common of these is the Intel Hex (ihex) format although other formats did exist at one point in time. The intel format is very simple, it is an ASCII text file with DOS style line endings that contains a sequence of lines like this one: :10012000194E79234623965778239EDA3F01B2CAA7
 * Intel hex files

Which represent the following:


 * Record types
 * 00 Data
 * 01 End Of File
 * 02 Extended Segment Address
 * 03 Start Segment Address
 * 04 Extended Linear Address
 * 05 Start Linear Address

The last line in the file must always be record type 01 which represents "End Of File" or :00000001FF

OS/2 text editors with Hex file support

 * jEdit - Java based - Hex file syntax highlighting built in - Current.
 * Preditor/2 - Hex editing support built in - Commercial - Discontinued.