microcoding a PC into a PDP-11 (was: RE: Classic Computers vs.

From: Bob Shannon <bshannon_at_tiac.net>
Date: Sun Sep 23 14:34:41 2001

Tony Duell wrote:

<snip>

> > Emulators are simply mimics of other machines, however they are implemented.
>
> Ah, so if the instruction set has been implemented before somewhere, then
> it's an emulator, is that your definition? So a PERQ running microcode to
> execute PDP11 instructions is a PDP11 emulator?
>
> While true, I think I could also justify describing that microcode as
> implementing the PDP11 instruction set on the PERQ.
>
> -tony

Agreed. Emulation is one way to implement an instuction set.

Emulating a PDP-11 on a PERQ in microcode is microcode, and emulation.

Emulating a PDP-11 on a PERQ in the PERQ machine code is only emulation.
Received on Sun Sep 23 2001 - 14:34:41 BST