Yeah, you are a little out of luck. Maybe @richm or @mkhayter still have old versions. The data files used to be stored on AWS and went where all living things eventually go - when that server was switched off due to lack of funding. What's on the FTP site are a few remnants, and the code to make yourself a new one. If you want to. The question is, why would you want that.
The way it worked was this: The simulator would simulate conditions, as a function of existing conditions (or lack thereof). And it would simulate drugs based on conditions. That is a world, where no drug causes any conditions, which means, they have no side effect. These are the _0 files. The _1 files resulted from adding those side effects based on a separate risk factor provided. The OMOP cup would then have various competing methods try to figure out what that risk was. Nice idea, except it forgets that there are all these relationships between everything called confounding. So the best method in the cup wasn't necessarily the best method in finding the risks in the real world.
Makes sense? What is your use case? What are you trying to do?
If you really want to recreate OSIM2, you will have somebody run the script building the transition matrix. So, you have to go to a data owner or subscriber. Happy to help you out if you can tell me more what it is you want to do.