The directives of the SpectNetIDE Z80 Assembler representation are used for preprocessing — similarly as in the C and C++ programming languages — though their semantics are different.
Although you can add comments to the end of directives, they may not have labels.
The #IF Directive
You can use this directive for conditional compilation. The argument of the directive is a conditional expression, and it determines on which branch the compilation goes on. #IF works in concert with #ELSE and #ENDIF:
; Block #1
#if 2 > 3
ld a,b
#endif
; Block #2;
#if 2 < 3
nop
#else
ld b,c
#endif
; Block #3
#if $ > $+2
nop
#else
ld b,c
#endif
Here, Block #1 does not generate output, since the condition is false. Block #2 emits
a nop, as the condition is true. The fals condition value in Block #3 moves code
parsing to the #else branch, so it emits a ld b,c instruction.
The #IFDEF and #IFNDEF Directives
These directives works similarly to #IF. However, these check if a particular symbol has (#IFDEF) or has not (#IFNDEF) defined. So their single argument is an identifier name.
The #IFMOD and #IFNMOD Directives
These directives works similarly to #IF. However, these check if the code’s current model is the one specified with the identifier following the #IFMOD or #IFNMOD pragma. Here is a short sample of using this directive:
.model Spectrum48
#ifmod Spectrum128
BorderColor: .equ 5
RetAddr: .equ #2604
#else
BorderColor: .equ 4
RetAddr: .equ #12a2
#endif
Start:
.org #8000
ld a,BorderColor
out (#fe),a
jp RetAddr
You can use only these identifiers with this pragma (case-insensitively): SPECTRUM48,
SPECTRUM128, SPECTRUMP3, NEXT.
The #DEFINE and #UNDEF Directives
With the #DEFINE directive, you can explicitly define a symbol. Such a symbol has no concrete value, just its existence. With #UNDEF you may declare a symbol undefined.
#define SYMB
; Block #1
#ifdef SYMB
ld a,b
#endif
#undef SYMB
; Block #2;
#ifdef SYMB
nop
#else
ld b,c
#endif
According to this definition, the first block emits a ld, a,b instruction, the second one a
ld b,c instruction.
The #INCLUDE Directive
You can use this directive to load and process a source file from within another source file.
#INCLUDE accepts a string that names a file with its extension. The file name may contain either an absolute or a relative path. When a relative path is provided, its strating point is always the source file that holds the #INCLUDE directive.
Assume that this code is in the C:\Work folder:
#include "Symbol.z80Asm"
#include "./MyRules.z80Asm"
#include "/Common/scroll.z80Asm"
The compiler will check the C:\Work folder for the first two include filem and
C:\Work\Commmon for the third one.