* VAR and PLANT macros

var macro
   ds\0 0
\* equ *(a6)
\*@ equ *
   ds\0 \1
   endm

plant macro
   org varbase+\*@
   dc\0 \1
   endm

  end

* FRED VAR.X Y defines fred to be *(A6) and then
* allocates space for FRED by using DS.X Y,
* thereby advancing *.  If you omit the .X it
* will assume .W. If you only ever use 1 for Y,
* it may be as well to change the DS\0 \1 in the
* macro to DS\0 1. The DS\0 0 in the macro simply
* word-aligns the location counter if necessary.
* This macro also defines FRED@ to be *, which is
* intended for use by the PLANT macro.

* JIM PLANT.X Y initialises the variable JIM with
* value Y, by resetting the location counter to
* VARBASE+JIM@, and then using DC.X Y.  It is
* possible to initialise short arrays (such as
* declared by JIM VAR 3) by using JIM PLANT
* <1,2,3>. Note use of the angle brackets which
* forces the 1,2,3 into parameter 1 (thus DC.X Y
* becomes DC 1,2,3), omitting them would define
* parameter 1 as 1, p2 as 2, p3, as 3, so DC.X Y
* would become DC 1, with the 2 and 3 being
* ignored.

* The following order must be observed within the
* source file:
* 
* ORG 0 must come before first call to VAR.
* 
* All VAR declarations must come before any code
* which uses such variables because the assembler
* rejects forward references to anything which is
* not short absolute or PC relative (and these,
* being register-relative, are neither).
* 
* The label VARBASE must be declared (using
* VARBASE EQU *) wherever it is intended that the
* variables should be. If this is after rather
* than before code which sets up the base
* register (using LEA VARBASE,A6), it may be
* necessary to use RORG ???? instead of ORG ????
* between VAR declarations and code.
* 
* Any calls to the PLANT macro must come after
* the VARBASE label.
   end