Question

In Microcomputers, address 0X345E, what does the "X" mean? Similarly, address "0FFFFh", what does the "h" mean?

Answer 1

In a base number system, we have to represent numbers either using a prefix, suffix or using the subscript.

As there is always a need to specify the number in a base system thus above methodologies came into the picture.

In the similar way for hexadecimal numerals which are widely used by computer system designers and programmers, a representation came into prevalence i.e. specifying the hexadecimal digits as nibble, which is half of a byte.

Notations for hexadecimal:

A prefix "0x" is used for numeric constants represented in hex in environments like Unix shells, AT&T assembly language, c programming etc.

Here "0" tells the parser that it's dealing with a constant and not an identifier. And "x" is an arbitrary choice to specify the number base.

A suffix "h" or "H" is also used for denoting hexadecimal number and mostly used in intel derived assembly language.

Hence in question above 0x345E represents a hexdecimal number 345E.

And 0FFFFh also represents a hexadecimal number FFFF.