Illegal instruction for currently selected processor(s)

A source line specifies an instruction that can't be assembled for the
current processor. For example,

   P8086
   push  1234h      ;no immediate push on 8086 

When Turbo Assembler first starts assembling a source file, it generates
instructions for the 8086 processor, unless told to do otherwise. If you
wish to use the extended instruction mnemonics available on the
186/286/386 processors, you must use one of the directives that enables
those instructions (P186, P286, P386).