Integer constants

The Assembler supports four representations of integer constants:

A decimal constant is defined by a sequence of decimal digits (0-9).
Example: 5, 512, 1024
A hexadecimal constant is defined by a dollar character ( $) followed by a sequence of hexadecimal digits (0-9, a-f, A-F).
Example: $5, $200, $400
An octal constant is defined by the commercial at character ( @) followed by a sequence of octal digits (0-7).
Example: @5, @1000, @2000
A binary constant is defined by a percent character followed by a sequence of binary digits (0-1)
Example :
```
%101, %1000000000, %10000000000
```

The default base for integer constant is initially decimal, but it can be changed using the BASE - Set number base assembler directive. When the default base is not decimal, decimal values cannot be represented, because they do not have a prefix character.