Inquiry on Keil Compiler Version and MDK V6 Compatibility

I have a couple of queries regarding Keil products:

  1. In one of our projects, we have used ARM Compiler V5.06 update 5 (build 528) along with Keil µVision IDE v5.24a. Is it possible to purchase the same version? If yes, could you please provide the availability details and pricing?
  2. If we upgrade to Keil MDK Version 6 Professional (ARM Compiler 6 / ArmClang), will it provide backward compatibility with projects developed using ARM Compiler 5 (V5.06 update 5)? Specifically:
  • Can the existing project be built without requiring source code modifications?
  • Is it possible to retain the legacy ARMCC (v5) toolchain within MDK v6 for seamless migration?

Are there any known limitations related to compiler differences (e.g., language compliance, linker behavior, startup files, or libraries) that may impact our current project