On Jul 16, 4:22*pm, Roland Perry wrote:
In message
, at
05:47:38 on Wed, 16 Jul 2008, 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?