IBM propriety CPU for AiX and A400 UNIX servers
Oh boy, that’s like saying latest Intel processors are made for Windows 2.0.
By A400, I presume you mean AS/400, which was renamed to OS/400 way back in
1988, only to be renamed a few more times since, currently it’s known as simply…
i. Also, not UNIX (though providing compatibility layer for AIX software, AIX being the IBM UNiX)