Request for cross-assembler for Z-80

[Louis Sherwin]

I am looking for a cross-assembler for the Z-80 to use on a 
Unix system (System V) as a development tool. We are currently
running on a Cromenco (sp?) using their assembler. 

We also need a linker and loader as part of the package.
Source code for the assembler is also highly desirable since
we have made some changes to the assembler we are now using.

thanks for your assistance. Louie Sherwin