BIG ENDIAN (constant)

The BIG ENDIAN is a constant that values non zero if the rappresentation of data on the local CPU is in big endian. Endianness is a concept that concerns the order in which the bytes of a multi-byte number are stored in memory.

Imagine having an integer that spans more than one byte. Endianness determines whether the most significant byte (the one that represents the highest digit) is stored first (at the lowest memory address) or last. In this case, the most significant byte is stored first. It is like reading a book from left to right, starting with the most important word.

Endianness is a fundamental aspect of computer architecture, as it affects how data is interpreted and manipulated. Different architectures use different endianness conventions. For example: Motorola 6809 is BIG ENDIAN, MOS 6502 is LITTLE ENDIAN.

In 8-bit computers, endianness was a crucial consideration, especially when it came to managing integers across multiple bytes. Since these computers had limited memory, it was essential to maximize storage space.

With limited memory available, it was essential to use each byte efficiently, and endianess directly affected arithmetic operations on multi-byte numbers, such as addition and subtraction. Moreover, when exchanging data between systems with different endianness, appropriate conversions is needed.

If you are writing code that directly manipulates memory, it is essential to know the endianness of the system to avoid data interpretation errors. If you are developing software that needs to run on different platforms, you need to account for endianness differences and implement data conversion mechanisms, for data that are not manager by ugBASIC itself.

EXAMPLE

 IF BIG ENDIAN THEN
    PRINT "This CPU is big endian"
 ENDIF