In article , () wrote:

On Fri, 26 Jan 2018 17:32:28 -0600
wrote:
In article , () wrote:

On Fri, 26 Jan 2018 06:32:11 -0600
wrote:
In article , ()
wrote:
That sounds highly unlikely. You can still buy chips designed in the
70s if you so desi

https://www.digikey.co.uk/catalog/en...roup/z80/15507

But you can't create the circuit boards and assemble them at
affordable costs.
Which is what I said.

so the chances of whatever microcontroller the radios used being
unavailable is pretty slim. Plus the analogue radio components and
op-amps will always be available until someone invents usable
optotronics. More than likely the cost of redesigning the board for
SMDs was more than railtrack was prepared to pay.

So you know more than a multi-national radio manufacturing company?
It's a true story, as told to me by our salesman to Railtrack at the
time.

Told to you by a salesman? Oh well, it MUST be true then.

He was an engineer who maintained the company's relationship with the
railway. We made all the NRN radios in the 1980s and 1990s (at least all
those I've seen in cabs on depot visits in recent years). I worked there
for over 25 years so knew a lot about how the kit was manufactured.

You'll know then which components were impossible to source. Feel free to
fill us in on which ones they were.

As I've said more than once it wasn't a components problem. It's that the
boards were unmanufacturable at any affordable price. They needed
redesigning for modern components and assembly methods which meant starting
the approval process all over again from scratch.

--
Colin Rosenstiel

In message , at 05:58:57
on Mon, 29 Jan 2018, remarked:

You'll know then which components were impossible to source. Feel free to
fill us in on which ones they were.

As I've said more than once it wasn't a components problem. It's that the
boards were unmanufacturable at any affordable price. They needed
redesigning for modern components

I think Spud wants to know why they couldn't use the old boards with the
*old* components.
--
Roland Perry

In article , (Roland Perry)
wrote:

In message , at
05:58:57 on Mon, 29 Jan 2018, remarked:

You'll know then which components were impossible to source. Feel free
to fill us in on which ones they were.

As I've said more than once it wasn't a components problem. It's that the
boards were unmanufacturable at any affordable price. They needed
redesigning for modern components

I think Spud wants to know why they couldn't use the old boards with
the *old* components.

What old boards? They would have to be made and assembled from scratch, an
unaffordable prospect for the additional radios Railtrack wanted.

--
Colin Rosenstiel

In message , at 12:25:30
on Mon, 29 Jan 2018, remarked:

You'll know then which components were impossible to source. Feel free
to fill us in on which ones they were.

As I've said more than once it wasn't a components problem. It's that the
boards were unmanufacturable at any affordable price. They needed
redesigning for modern components

I think Spud wants to know why they couldn't use the old boards with
the *old* components.

What old boards? They would have to be made and assembled from scratch, an
unaffordable prospect for the additional radios Railtrack wanted.

So we may be getting closer - the problem was a lack of boards, not a
lack of components to put on them?
--
Roland Perry

In article , (Roland Perry)
wrote:

In message , at
12:25:30 on Mon, 29 Jan 2018, remarked:

You'll know then which components were impossible to source. Feel
free to fill us in on which ones they were.

As I've said more than once it wasn't a components problem. It's that
the boards were unmanufacturable at any affordable price. They needed
redesigning for modern components

I think Spud wants to know why they couldn't use the old boards with
the *old* components.

What old boards? They would have to be made and assembled from scratch,
an unaffordable prospect for the additional radios Railtrack wanted.

So we may be getting closer - the problem was a lack of boards, not a
lack of components to put on them?

Unmanufacturable covers a range of situations.

--
Colin Rosenstiel

On 30/01/2018 00:03, wrote:
In article , (Roland Perry)
wrote:

In message , at
12:25:30 on Mon, 29 Jan 2018, remarked:

You'll know then which components were impossible to source. Feel
free to fill us in on which ones they were.

As I've said more than once it wasn't a components problem. It's that
the boards were unmanufacturable at any affordable price. They needed
redesigning for modern components

I think Spud wants to know why they couldn't use the old boards with
the *old* components.

What old boards? They would have to be made and assembled from scratch,
an unaffordable prospect for the additional radios Railtrack wanted.

So we may be getting closer - the problem was a lack of boards, not a
lack of components to put on them?

Unmanufacturable covers a range of situations.

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

In message , at 09:08:18 on Tue, 30 Jan
2018, Someone Somewhere remarked:
You'll know then which components were impossible to source. Feel
free to fill us in on which ones they were.

As I've said more than once it wasn't a components problem. It's that
the boards were unmanufacturable at any affordable price. They needed
redesigning for modern components

I think Spud wants to know why they couldn't use the old boards with
the *old* components.

What old boards? They would have to be made and assembled from scratch,
an unaffordable prospect for the additional radios Railtrack wanted.

So we may be getting closer - the problem was a lack of boards, not a
lack of components to put on them?
Unmanufacturable covers a range of situations.

Nothing that was manufactered is unmanufacturable - it may not be
reasonably economic to do so, 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.
--
Roland Perry