The source code as I recieved from Pete was written in Z80 Assembly. Compilation via a current Z80 macro assembler didn’t work, there were declerations and directives for a specific assembler.
Looking at the Dos .bat files they used to build, I tried to find out which compiler was used, but my initial search didn’t yield any results.
Another Zyklus builder in Holland took it to some Retro Computing friends and discovered that it was 2500 A.D. Systems Z80 Macro assembler. I spend an evening searching and while some versions are still downloadable, the version needed (4.0X) isn’t completely.
I think I have a working compiler, but not the linker. Perhaps and older version of the linker can be used. I’ll try this in the coming days.
Meanwhile, I’m trying to wrap my head around the code. Thankfully it’s extraordinary well documented!