Re: Intel vs 6502

[mjmahon@aol.com (Michael J. Mahon)]

Bryan Parkoff wrote:

<snip>
>    If we have to break black cover before we can see naked IC wires inside
>microprocessor, it might provide us more information before we can be able
>to build one from scratch.  What do you think?

The wiring of a microprocessor is _not_, in general, visible from looking
at the chip.  There are buried layers of metal or polysilicon which are
not observable without very specialized equipment and precision
destructive techniques.

It is not a practical way to design a 65xxx clone (or extension), but
the way you would get a circuit from a chip is to grind, etch, and photo-
graph repeatedly to recover the mask designs, then scan the masks
and extract the circuit from them.  These are highly specialized tasks
and the extraction requires specialized software--and it still requires
substantial expert interaction to get the correct results.

Such an effort is only justifiable when no other course (such as
functional cloning) can be employed, and when the monetary
stakes are high enough to justify the high cost.

Finally, there's the issue that any design derived from such an
effort is still covered by the original owner's copyright...if they
catch you.  ;-)

-michael

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