Apple Pascal may only "externally" link assembly routines. However, Pascal
procedures compiled seperately can be placed into a library unit and
accessed with the USES command.
Assembly code may also be placed into library units, provided it's called
from the Pascal level. To do so: assemble the code file(s) and create a
Pascal unit which refers to each .PROC and .FUNC of the code as EXTERNAL.
To create an intrinsic unit containing assembly code, link the external
references to the compiled P-code unit structure, then install this completed
unit in the System.library file on your boot disk.
Since the regular units which reference assembly code are not linked
prior to installing the library file, install the unlinked Pascal units
in the System.library or in your own library file to keep these assembly code
file(s) on hand. Link the assembly routines into the final code file when
you link the host program with this regular unit.