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Z80 Relocating Macro Assembler
Conditional Assembly
ELSE
Else directive. This pseudo-op toggles the current IF
condition. If the current IF condition is false, now it is true,
and vise versa. For example,
PRNTOUT
;call printer output routine
IF
PARPNT
;if parallel printer
CALL
PAROUT
;call parallel output
ELSE
;otherwise
CALL
SEROUT
;call serial output
ENDIF
;terminate if block
if PARPNT is true, the first call will be assembled, otherwise
the second one will be used.
IF0
This pseudo-op is a special form of the IF pseudo-op. It
takes no parameters, but assembles the following lines of code
only in one-pass mode assemblies.
IF1
This is similar to the IF0 pseudo-op, except that it returns
a true conditional only on pass 1 of 2-pass mode.
IF2
This is similar to the IF1 pseudo-op, except that it returns
a true conditional only on pass 2 of 2-pass mode.
IFDEF
<SYMBOL>
The IFDEF pseudo-op takes a valid symbol as an operand, and
assembles the following lines of code only if the symbol has been
defined in the module as absolute, relative or external.
IFNDEF
<SYMBOL>
The IFNDEF pseudo-op performs the opposite function as
IFDEF. The conditional block is assembled only if the given
symbol is undefined.
Z80ASM User's Manual Copyright (c) 1984 SLR Systems
Page 5-3