Getting this old software to run can be very hairy on modern hardware, but I’m pleasantly suprised with the ease of this  – so far.

I’m using Windows XP on a virtual box on my Mac. With a shared dir to move the code from my main system where I can freely edit. This is a workable solution for now, but I’m planning to build a docker container with MS DOS in QEMU, so that I can just compile directly from my command line. I’ll do that once I’ve got everything required to complete a full build done.

Going through the old source archive, they used batch files to build everything. Some items were specific to the In-Circuit Emulator they used during development. Others were part of cross-platoform compliation. Right now I’m figuring out the basics. Getting the .ASM files to compile, and they all actually do, although most with some kind of “Undefined Symbol” notification – still generating an OBJ though. The goal is to build it fully and burn new EPROMS based on this build. If that runs succesfully on the Zyklus, we got a good starting point.

Using command line tool, I can convert the bin to HEX code, which is what I can use in the C Arrays in the MCLZ8 emulator.

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!