This archive contains the full source code to the disc image (boot sequence, applications, etc.) for the latest beta HardDisc4 build. The archive should be unpacked using UnTarBZ2, available from the Miscellaneous downloads page.
Note that some components (e.g. SparkFS) are distributed as precompiled modules (“binary blobs”). In these instances the source code will – obviously – not be included here.
For detailed build instructions, see How to build RISC OS.