* Etienne von Wettingfeld:   
      
   > IIRC it has to do with the ability to auto-boot CP/M.   
      
   Well... Close :)   
      
   The C128 was designed to be compatible with all official C64 addons -   
   which included the C64 CP/M cartridge, which had compatibility issues   
   on later revision C64s already. Designing in the Z80 (so the CP/M cartridge   
   would be redundant, and no longer an issue..) was cheaper than trying to work   
   around the issues.   
      
   There were other problematic cartridges: Cartridges that (ab)used Ultimax   
   mode to hijack the reset-, NMI- and interrupt vectors. This included some   
   of Commodore's own (including the Magic Voice). These would cause problems,   
   since the system hadn't been configured for C64 mode yet.   
      
   This is the real reason the c128 initially boots using the Z80: It probes   
   whether the system needs to boot in CP/M, 128 or 64 mode, while the 8502   
   was still halted.   
      
   Get it from the horse's mouth (Not that I'd call Bil a horse, mind):   
      
   https://www.reddit.com/r/c128/comments/682da4/c128_ama_from_bil_herd/   
      
   --   
   Martijn van Buul - pino@dohd.org   
      
   --- SoupGate-Win32 v1.05   
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