Home |
Search |
Today's Posts |
|
London Transport (uk.transport.london) Discussion of all forms of transport in London. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#12
|
|||
|
|||
Last days of the 172s on the electrified GOBLIN
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 |
#13
|
|||
|
|||
Last days of the 172s on the electrified GOBLIN
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 |
#14
|
|||
|
|||
Last days of the 172s on the electrified GOBLIN
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 |
#15
|
|||
|
|||
Last days of the 172s on the electrified GOBLIN
|
#16
|
|||
|
|||
Last days of the 172s on the electrified GOBLIN
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 |
#17
|
|||
|
|||
Last days of the 172s on the electrified GOBLIN
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. |
#18
|
|||
|
|||
Last days of the 172s on the electrified GOBLIN
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 |
#19
|
|||
|
|||
Last days of the 172s on the electrified GOBLIN
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. |
#20
|
|||
|
|||
Last days of the 172s on the electrified GOBLIN
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. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
GOBLIN 172s: where do they go during their hols? | London Transport | |||
Last two days of Routemasters | London Transport |