Someone Somewhere wrote:
On 30/01/2018 10:06, Roland Perry wrote:
In message , at 09:08:18 on Tue, 30 Jan
2018, Someone Somewhere remarked:


Nothing that was manufactered is unmanufacturable - it may not be
reasonably economic to do so,Â* or in certain cases legislation may
prevent it (lead etc) but if it was built once, it could be built again.

There are whole generations of custom-chips which aren't manufacturable
any more. Either the company which made them originally has gone out of
business/disappeared within another that's not longer in the foundry
business, or the tools and machinery required to produce a new batch
have long since been consigned to the dustbin of history.

A handful of generic chips may still be available, so you could perhaps
get a brand-new Z80 equivalent/clone processor chip to build a replica
Amstrad CPC464, but good luck getting Ferranti or SGS to make you a
fresh one of the ULAs.

You could still recreate them with enough time and money - they aren't
made of unobtanium - so it's economics. Now to rebuild the Ferranti fab
may be a ludicrous amount of money, but it's theoretically possible.

Or of course you could use FPGAs to do the same thing these days.


Would it be feasible to simply emulate all the old electronics and computer
components in software, running on a standard modern commodity CPU? The
modern CPU would be so much faster that it might deliver enough performance
to be able to precisely emulate the timing as well as the behaviour of the
old stuff.