The historical significance of DEC and the PDP-7, -8, -11 and VAX
The 6800, 6502, 6809, 68000 and ARM instruction sets were all heavily influenced by the PDP-11.<p>The auto post-increment&#x2F;pre-decrement addressing modes of the 6809, 68000 and ARM exist on the PDP-11.<p>The set of 2&#x27;s complement branch instructions and related flags for all of them is pretty much exactly the same (well 6502 does not implement the full set).<p>It didn&#x27;t have to be this way- for example, the instruction mnemonics could have been the IBM 360 ones..