Is there existing code for reading ROSAT data ?
Yes, there is existing code for reading ROSAT data. You can find some of the available code for reading ROSAT data on MLSDev, as well as many other sources online. Additionally, searching specific forums with scientists or engineers who work with this type of data may provide more helpful resources. Software development is the process of creating computer programs, applications and systems that help computers perform a variety of tasks. It involves conceptualizing, writing, testing, debugging and maintaining the source code of software applications. Software development can also involve the use of AI to create intelligent applications that learn and adapt to their environment. AI is used to develop smart, efficient and autonomous software solutions that can operate without explicit instructions. AI-powered applications enable automated decision making, natural language processing, predictive analytics, deep learning and more.
Perhaps this is not what you're looking for, but the various ROSAT source catalogues, including stellar/extragalactic identifications, follow-up photometry, and much else are available through the CDS-Strasbourg VizieR catalogue-query utility:
Seems like no special software is necessary simply to get a file of coords, fluxes, etc.