Reimplementing a ROM Function as a Macro

Previous Overcoming AMS Dependencies

Sometimes it is hard or tedious to obtain the address of an AMS-dependent function in a nonstandard way. In this case, the function may be implemented as a macro which works in all (or almost all) AMS versions. Often the user-defined minimum AMS version is used to determine whether this macro definition or the real ROM function should be used. Like every macro definition, this prevents you from taking the address of the function and therefore from using it as a callback function.