Forum OpenACS Q&A: Re: compiling OMSI PASCAL programs in DEC RT57XM monitor
There's a reason the MC 68000 assembly language looks much like the VAX's ... Gordon Bell's general register design and orthogonal instruction set for the 16-bit PDP-11 was the basis for the later VAX and also the 68K. The 68K was less orthogonal that either the PDP-11 or VAX. With these latter machines, operands could almost always be either memory or a register and the instruction set was very regular.
The PDP-11 is the only computer I'm aware of for which you can write a program which fills all memory with a copy of itself - running backwards!
Where pc is the Program Counter, i.e. the register that points to the current instruction (actually points one word beyond as it is executing).
And of course the PDP-11 is why C has autoincrement and autodecrement operators ... they map directly onto the operand modes supported by the hardware.
Not only did Whitesmith's C compiler suck, so did the people at Whitesmith's.