MIG

On Jul 16, 4:22 pm, Roland Perry <rol...@perry.co.uk> wrote:
> In message
> <372d84e1-8cec-47fa-bea5-70dd0dd7a...@y21g2000hsf..com>, at
> 05:47:38 on Wed, 16 Jul 2008, thagor2...@ remarked:
>
> >From wikipedia:
>
> >"A control store is the part of a CPU's control unit that stores the
> >CPU's microprogram"
>
> >"A control store is usually implemented as a diode-array of read-only
> >memory"
>
> I'm a fan of Wikipedia, but that stuff is just gibberish.
>
> >So I guess at that level you could put forward a valid argument for it
> >being hard wired diodes, or software in the sense of the way the
> >diodes are wired. Or both! But then again I suppose you could say the
> >same about any read only ROM.
>
> There any many technologies that can be used to implement a ROM,
> including the presence and absence of diodes in a matrix, and even the
> ability to erase or restore such diodes in the field. This is
> ludicrously technology-specific, however, and who is to say what a
> generic CPU uses to store its microcode. (If you had asked me yesterday,
> I might have said "the presence of absence of conductors between logic
> gates").

This all might as well be a foreign language to me, but ... does one
or other hypothesis explain why a card can be permanently disabled by
being touched on a pad rather than being able to be reset?