On 2024-04-16 00:09, Lawrence D'Oliveiro wrote:
> On Mon, 15 Apr 2024 11:34:28 +0100, The Natural Philosopher wrote:
>
>> Many pieces of industrial gear still run on DOS
>
> Would you entrust mission-critical business functions to obsolete,
> unsupported software?

On industrial environment, which is not a business environment, yes, I
would.

>
>> you dont upgrade kit that works, for functionality, only to fix problems
>
> The trouble with “if it ain’t broke, don’t fix it” is when you wait until
> it *is* broke, and only then discover that you have no idea how to fix it.

You don't replace an industrial setup worth millions just because the
computer is "obsolete". The computer is just part of it. An industrial
setup is intended to keep working decades.

--
Cheers, Carlos.

On 2024-04-16 12:35, The Natural Philosopher wrote:
> On 15/04/2024 23:09, Lawrence D'Oliveiro wrote:
>> On Mon, 15 Apr 2024 11:34:28 +0100, The Natural Philosopher wrote:
>>
>>> Many pieces of industrial gear still run on DOS
>>
>> Would you entrust mission-critical business functions to obsolete,
>> unsupported software?
> People trust a lot of things to WIN XP
>
> Freedos is supported
>
> But you completely missed the point. If a piece of hardware and software
> works as intended, it doesn't matter how 'obsolete or unsupported' it
> is. Viz nuclear power stations running on PDP11s and so on.
>
> It is clear you do not actually understand DOS at all: There is nothing
> TO support. It is simply a program loader. Everything else is the user
> application, as DOS allows Assembly language coded bare metal
> programming if you want it to.

And there is no network access to protect from. The thing is as secure
as it was when built. You only have to protect from physical access.

The real problem is hardware breakdown. There are no spares.

Machines installed 1998 could have been designed 5 years before. Using
an actual 8086 in an expensive industrial PC was possible, a Pentium
would be normal.

--
Cheers, Carlos.

"Carlos E.R." <robin_listas@es.invalid> writes:
> On 2024-04-16 12:48, Richard Kettlewell wrote:
>> Nuno Silva <nunojsilva@invalid.invalid> writes:
>>> One thing about this topic that has been popping up in several
>>> outlets... as El Reg points out in [1]:
>>>
>>> «The agency noted that its system was installed in 1998, when
>>> floppies were still in common use and, er, "computers didn't have
>>> hard drives." *That doesn't exactly match reality*,»
>>>
>>> (emphasis mine) What happened, somebody mixed the years or tried to make
>>> up an explanation and came up with a bad one? Or am I missing context?
>>> IIRC hard drives were commonplace in 1998, even if not so large.
>>>
>>> [1] https://www.theregister.com/2024/04/09/san_francisco_muni_floppy_disks/
>> The disks are 5.25” disks and that does put the origins of the
>> technology back into an era where hard drives were at least much less
>> common - but certainly very long in the tooth by the time the system was
>> deployed.
>
> Er... no. 5.25 floppies coexisted with hard drives.

I did not say otherwise.

--
https://www.greenend.org.uk/rjk/

On 16.04.2024 um 14:07 Uhr Carlos E.R. wrote:

> However, hard disks could break down if used on a vehicle, the
> vibrations could destroy them. On a single purpose dedicated machine,
> it could make sense to use floppies instead of hard disks.

Floppies are being destroyed slowly when being used because the head
has traction on the floppy disk.

I've seen floppies where that was visible because the area where the
head ran was brighter than the verge.

Also, dust comes in and creates additional attrition.
Moisture is also very bad for them.

I love playing around with such things, but I wouldn't like to have a
production system relying on it.

--
kind regards
Marco

Send spam to 1713269221muell@cartoonies.org

Lawrence D'Oliveiro <ldo@nz.invalid> wrote:
>On Mon, 15 Apr 2024 10:55:16 +0200, Marc Haber wrote:
>> I don't know whether we² are going to transition back to the unsuffixed
>> names of packages and symbols once all libraries are 64bit time_t.
>> Personally, I'd consider that a waste.
>
>You think so? I think it makes sense to get rid of the superfluous suffix,
>once it has served its purpose.

That would practically mean touching hundreds if not thousands of
packages, and another transition of this epic size.

--
----------------------------------------------------------------------------
Marc Haber | " Questions are the | Mailadresse im Header
Rhein-Neckar, DE | Beginning of Wisdom " |
Nordisch by Nature | Lt. Worf, TNG "Rightful Heir" | Fon: *49 6224 1600402

On 2024-04-16 15:39, Marco Moock wrote:
> On 16.04.2024 um 14:07 Uhr Carlos E.R. wrote:
>
>> However, hard disks could break down if used on a vehicle, the
>> vibrations could destroy them. On a single purpose dedicated machine,
>> it could make sense to use floppies instead of hard disks.
>
> Floppies are being destroyed slowly when being used because the head
> has traction on the floppy disk.
>
> I've seen floppies where that was visible because the area where the
> head ran was brighter than the verge.
>
> Also, dust comes in and creates additional attrition.
> Moisture is also very bad for them.
>
> I love playing around with such things, but I wouldn't like to have a
> production system relying on it.

There was software that kept the floppy drive turning non stop. When I
noticed that happening, I just opened the door or stopped the program.

At the time, if you needed to load some data, you had to use floppies.
There were no alternatives. Ok, there were some things, but
significantly more expensive. Mostly magnetic storage.

You could have some industrial machine doing a job; you designed the
task on your desktop, then fed it via floppy to the machine in the
machine shop.

Quite simple :-)

--
Cheers, Carlos.

On 16/04/2024 13:11, Carlos E.R. wrote:
> On 2024-04-16 00:09, Lawrence D'Oliveiro wrote:
>> On Mon, 15 Apr 2024 11:34:28 +0100, The Natural Philosopher wrote:
>>
>>> Many pieces of industrial gear still run on DOS
>>
>> Would you entrust mission-critical business functions to obsolete,
>> unsupported software?
>
> On industrial environment, which is not a business environment, yes, I
> would.
>
>>
>>> you dont upgrade kit that works, for functionality, only to fix problems
>>
>> The trouble with “if it ain’t broke, don’t fix it” is when you wait until
>> it *is* broke, and only then discover that you have no idea how to fix
>> it.
>
> You don't replace an industrial setup worth millions just because the
> computer is "obsolete". The computer is just part of it. An industrial
> setup is intended to keep working decades.
>
>
Back in the 80s worked on a terrible project - software to go in
underwater fibre repeaters.

Everything was a muddle, but one of the permies remarked 'at least we
are allowed to use silicon, now'

They had to stick with GERMANIUM until silicon devices had been around
25 years - the guaranteed product life span.

There are still more than a few PDPs and vaxen doing mission critical
stuff out there.

As the saying goes, 'A VAX is like an erect penis, It will stay up as
long as you don't fuck with it'

--
"When a true genius appears in the world, you may know him by this sign,
that the dunces are all in confederacy against him."

Jonathan Swift.

On 16/04/2024 13:20, Carlos E.R. wrote:
> On 2024-04-16 12:35, The Natural Philosopher wrote:
>> On 15/04/2024 23:09, Lawrence D'Oliveiro wrote:
>>> On Mon, 15 Apr 2024 11:34:28 +0100, The Natural Philosopher wrote:
>>>
>>>> Many pieces of industrial gear still run on DOS
>>>
>>> Would you entrust mission-critical business functions to obsolete,
>>> unsupported software?
>> People trust a lot of things to WIN XP
>>
>> Freedos is supported
>>
>> But you completely missed the point. If a piece of hardware and
>> software works as intended, it doesn't matter how 'obsolete or
>> unsupported' it is. Viz nuclear power stations running on PDP11s and
>> so on.
>>
>> It is clear you do not actually understand DOS at all: There is
>> nothing TO support. It is simply a program loader. Everything else is
>> the user application, as DOS allows Assembly language coded bare metal
>> programming if you want it to.
>
> And there is no network access to protect from. The thing is as secure
> as it was when built. You only have to protect from physical access.
>
> The real problem is hardware breakdown. There are no spares.
>
> Machines installed 1998 could have been designed 5 years before. Using
> an actual 8086 in an expensive industrial PC was possible, a Pentium
> would be normal.
>
Actually today one would probably plump for a Pi or ARM chip running
stripped down linux, and do the I/O other than via the old XT style
plugin boards I2C or USB, or very local networking. Or simply hang some
logic round the GPIO pins to make the thing look like an 8088 I/O bus 16
GPIO pins plus two more for read/write would emulate an 256 x 8 bit
wide IO bus.

--
There is nothing a fleet of dispatchable nuclear power plants cannot do
that cannot be done worse and more expensively and with higher carbon
emissions and more adverse environmental impact by adding intermittent
renewable energy.

On 16/04/2024 14:39, Marco Moock wrote:
> On 16.04.2024 um 14:07 Uhr Carlos E.R. wrote:
>
>> However, hard disks could break down if used on a vehicle, the
>> vibrations could destroy them. On a single purpose dedicated machine,
>> it could make sense to use floppies instead of hard disks.
>
> Floppies are being destroyed slowly when being used because the head
> has traction on the floppy disk.
>
> I've seen floppies where that was visible because the area where the
> head ran was brighter than the verge.
>
> Also, dust comes in and creates additional attrition.
> Moisture is also very bad for them.
>
> I love playing around with such things, but I wouldn't like to have a
> production system relying on it.
>
They were extremely reliable, especially when written and read by the
same drive.
To the point where a stock of drive chassis and blank floppies would
keep you going for decades

--
When plunder becomes a way of life for a group of men in a society, over
the course of time they create for themselves a legal system that
authorizes it and a moral code that glorifies it.

Frédéric Bastiat

On 16/04/2024 17:15, Carlos E.R. wrote:
> On 2024-04-16 15:39, Marco Moock wrote:
>> On 16.04.2024 um 14:07 Uhr Carlos E.R. wrote:
>>
>>> However, hard disks could break down if used on a vehicle, the
>>> vibrations could destroy them. On a single purpose dedicated machine,
>>> it could make sense to use floppies instead of hard disks.
>>
>> Floppies are being destroyed slowly when being used because the head
>> has traction on the floppy disk.
>>
>> I've seen floppies where that was visible because the area where the
>> head ran was brighter than the verge.
>>
>> Also, dust comes in and creates additional attrition.
>> Moisture is also very bad for them.
>>
>> I love playing around with such things, but I wouldn't like to have a
>> production system relying on it.
>
>
> There was software that kept the floppy drive turning non stop. When I
> noticed that happening, I just opened the door or stopped the program.
>
>
> At the time, if you needed to load some data, you had to use floppies.
> There were no alternatives. Ok, there were some things, but
> significantly more expensive. Mostly magnetic storage.
>
> You could have some industrial machine doing a job; you designed the
> task on your desktop, then fed it via floppy to the machine in the
> machine shop.
>
> Quite simple :-)
>
The modern sneakernet equivalent is an SD card or a 'thumb drive'

--
When plunder becomes a way of life for a group of men in a society, over
the course of time they create for themselves a legal system that
authorizes it and a moral code that glorifies it.

Frédéric Bastiat

On 2024-04-16 21:18, The Natural Philosopher wrote:
> On 16/04/2024 13:11, Carlos E.R. wrote:
>> On 2024-04-16 00:09, Lawrence D'Oliveiro wrote:
>>> On Mon, 15 Apr 2024 11:34:28 +0100, The Natural Philosopher wrote:
>>>
>>>> Many pieces of industrial gear still run on DOS
>>>
>>> Would you entrust mission-critical business functions to obsolete,
>>> unsupported software?
>>
>> On industrial environment, which is not a business environment, yes, I
>> would.
>>
>>>
>>>> you dont upgrade kit that works, for functionality, only to fix
>>>> problems
>>>
>>> The trouble with “if it ain’t broke, don’t fix it” is when you wait
>>> until
>>> it *is* broke, and only then discover that you have no idea how to
>>> fix it.
>>
>> You don't replace an industrial setup worth millions just because the
>> computer is "obsolete". The computer is just part of it. An industrial
>> setup is intended to keep working decades.
>>
>>
> Back in the 80s worked on a terrible project - software to go in
> underwater fibre repeaters.
>
> Everything was a muddle, but one of the permies remarked 'at least we
> are allowed to use silicon, now'
>
> They had to stick with GERMANIUM until silicon devices had been around
> 25 years -  the guaranteed product life span.

Heh :-)

>
> There are still more than a few PDPs and vaxen doing mission critical
> stuff out there.
>
> As the saying goes, 'A VAX is like an erect penis, It will stay up as
> long as you don't fuck with it'

:-)

--
Cheers, Carlos.

On 2024-04-16 21:31, The Natural Philosopher wrote:
> On 16/04/2024 17:15, Carlos E.R. wrote:
>> On 2024-04-16 15:39, Marco Moock wrote:
>>> On 16.04.2024 um 14:07 Uhr Carlos E.R. wrote:
>>>
>>>> However, hard disks could break down if used on a vehicle, the
>>>> vibrations could destroy them. On a single purpose dedicated machine,
>>>> it could make sense to use floppies instead of hard disks.
>>>
>>> Floppies are being destroyed slowly when being used because the head
>>> has traction on the floppy disk.
>>>
>>> I've seen floppies where that was visible because the area where the
>>> head ran was brighter than the verge.
>>>
>>> Also, dust comes in and creates additional attrition.
>>> Moisture is also very bad for them.
>>>
>>> I love playing around with such things, but I wouldn't like to have a
>>> production system relying on it.
>>
>>
>> There was software that kept the floppy drive turning non stop. When I
>> noticed that happening, I just opened the door or stopped the program.
>>
>>
>> At the time, if you needed to load some data, you had to use floppies.
>> There were no alternatives. Ok, there were some things, but
>> significantly more expensive. Mostly magnetic storage.
>>
>> You could have some industrial machine doing a job; you designed the
>> task on your desktop, then fed it via floppy to the machine in the
>> machine shop.
>>
>> Quite simple :-)
>>
> The modern sneakernet equivalent is an SD card or a 'thumb drive'

Also a nasty attack vector.

An USB thumb drive can be manufactured to emulate a keyboard, for
instance, and enter commands to an otherwise isolated and secured machine.

With a floppy, you had to reboot to activate the virus. Or load a program.

--
Cheers, Carlos.

On Tue, 16 Apr 2024 14:11:05 +0200, Carlos E.R. wrote:

> On 2024-04-16 00:09, Lawrence D'Oliveiro wrote:
>
>> The trouble with “if it ain’t broke, don’t fix it” is when you wait
>> until it *is* broke, and only then discover that you have no idea how
>> to fix it.
>
> You don't replace an industrial setup worth millions just because the
> computer is "obsolete".

If you could really afford to spend millions on the hardware, then it
would be peanuts by comparison to add on a software support contract that
will provide maintenance and updates for the expected life of the
hardware.

Marc Haber wrote:
> Lawrence D'Oliveiro <ldo@nz.invalid> wrote:
>> On 64-bit systems (which is what most of us would be running by now),
>
> You need to think beyond your desktop PC. Linux runs on billions of
> embedded systems, many of them being a 32 bit architecture and bound
> to stay there. Embedded systems tend to have an order of magnitude
> more in lifetime. The year 2038 is already here for those systems.
>

So don't get in an elevator on Jan 18/19 2038?

On 2024-04-17 02:42, Lawrence D'Oliveiro wrote:
> On Tue, 16 Apr 2024 14:11:05 +0200, Carlos E.R. wrote:
>
>> On 2024-04-16 00:09, Lawrence D'Oliveiro wrote:
>>
>>> The trouble with “if it ain’t broke, don’t fix it” is when you wait
>>> until it *is* broke, and only then discover that you have no idea how
>>> to fix it.
>>
>> You don't replace an industrial setup worth millions just because the
>> computer is "obsolete".
>
> If you could really afford to spend millions on the hardware, then it
> would be peanuts by comparison to add on a software support contract that
> will provide maintenance and updates for the expected life of the
> hardware.

Which probably they have. They get what they pay for, subject to terms
and conditions.

--
Cheers, Carlos.

On Wed, 17 Apr 2024 04:45:43 +0200, Carlos E.R. wrote:

> On 2024-04-17 02:42, Lawrence D'Oliveiro wrote:
>
>> On Tue, 16 Apr 2024 14:11:05 +0200, Carlos E.R. wrote:
>>
>>> On 2024-04-16 00:09, Lawrence D'Oliveiro wrote:
>>>
>>>> The trouble with “if it ain’t broke, don’t fix it” is when you wait
>>>> until it *is* broke, and only then discover that you have no idea how
>>>> to fix it.
>>>
>>> You don't replace an industrial setup worth millions just because the
>>> computer is "obsolete".
>>
>> If you could really afford to spend millions on the hardware, then it
>> would be peanuts by comparison to add on a software support contract
>> that will provide maintenance and updates for the expected life of the
>> hardware.
>
> Which probably they have.

Then the computer is not “obsolete”, if you can still get support for it.

On Tue, 16 Apr 2024 20:29:52 +0100, The Natural Philosopher wrote:

> On 16/04/2024 14:39, Marco Moock wrote:
>
>> I love playing around with such things, but I wouldn't like to have a
>> production system relying on it.
>>
> They were extremely reliable ...

Floppies were not reliable. Prior to getting my first CD writer, I backed
up my important programs onto two sets of floppies. Came time to move to
CDs, I discovered read errors--on both copies of the same disk! Luckily
they were in different files.

When you bought some new software that came on floppy, the immediate wise
thing to do was to make a working copy and use that. And keep the original
away somewhere safe.

On Tue, 16 Apr 2024 23:15:49 +0200, Carlos E.R. wrote:

> On 2024-04-16 21:31, The Natural Philosopher wrote:
>>
>> The modern sneakernet equivalent is an SD card or a 'thumb drive'
>
> Also a nasty attack vector.

Not sure an SD card can do that, but a USB device, yes.

Hence devices like this <https://github.com/robertfisk/USG/wiki>.

On 17/04/2024 04:27, Lawrence D'Oliveiro wrote:
> On Wed, 17 Apr 2024 04:45:43 +0200, Carlos E.R. wrote:
>
>> On 2024-04-17 02:42, Lawrence D'Oliveiro wrote:
>>
>>> On Tue, 16 Apr 2024 14:11:05 +0200, Carlos E.R. wrote:
>>>
>>>> On 2024-04-16 00:09, Lawrence D'Oliveiro wrote:
>>>>
>>>>> The trouble with “if it ain’t broke, don’t fix it” is when you wait
>>>>> until it *is* broke, and only then discover that you have no idea how
>>>>> to fix it.
>>>>
>>>> You don't replace an industrial setup worth millions just because the
>>>> computer is "obsolete".
>>>
>>> If you could really afford to spend millions on the hardware, then it
>>> would be peanuts by comparison to add on a software support contract
>>> that will provide maintenance and updates for the expected life of the
>>> hardware.
>>
>> Which probably they have.
>
> Then the computer is not “obsolete”, if you can still get support for it.

You can still get spare parts for 1950s cars. That doesn't mean they are
flawless or not obsolete.

Let's rephrase it. You have a system running on DEC PDP-11s: The guys
who wrote the software are dead, the company that supplied it went out
of business years ago, and no one will even offer a support contract on
it, But it runs your trains perfectly.

To replace it, a large software company quoted you $5m.

What do you do?

--
“A leader is best When people barely know he exists. Of a good leader,
who talks little,When his work is done, his aim fulfilled,They will say,
“We did this ourselves.”

― Lao Tzu, Tao Te Ching

On 17/04/2024 08:21, Lawrence D'Oliveiro wrote:
> On Tue, 16 Apr 2024 23:15:49 +0200, Carlos E.R. wrote:
>
>> On 2024-04-16 21:31, The Natural Philosopher wrote:
>>>
>>> The modern sneakernet equivalent is an SD card or a 'thumb drive'
>>
>> Also a nasty attack vector.
>
> Not sure an SD card can do that, but a USB device, yes.
>
> Hence devices like this <https://github.com/robertfisk/USG/wiki>.

What else is a raspberry PI than a device that boots not from a floppy,
but from an SD card?

There are floppy emulators that take SD cards that can be used to boot
old PCs etc.

--
No Apple devices were knowingly used in the preparation of this post.

In comp.os.linux.misc The Natural Philosopher <tnp@invalid.invalid> wrote:
> On 17/04/2024 04:27, Lawrence D'Oliveiro wrote:
>> On Wed, 17 Apr 2024 04:45:43 +0200, Carlos E.R. wrote:
>>
>>> On 2024-04-17 02:42, Lawrence D'Oliveiro wrote:
>>>
>>>> On Tue, 16 Apr 2024 14:11:05 +0200, Carlos E.R. wrote:
>>>>
>>>>> On 2024-04-16 00:09, Lawrence D'Oliveiro wrote:
>>>>>
>>>>>> The trouble with “if it ain’t broke, don’t fix it” is when you wait
>>>>>> until it *is* broke, and only then discover that you have no idea how
>>>>>> to fix it.
>>>>>
>>>>> You don't replace an industrial setup worth millions just because the
>>>>> computer is "obsolete".
>>>>
>>>> If you could really afford to spend millions on the hardware, then it
>>>> would be peanuts by comparison to add on a software support contract
>>>> that will provide maintenance and updates for the expected life of the
>>>> hardware.
>>>
>>> Which probably they have.
>>
>> Then the computer is not “obsolete”, if you can still get support for it.
>
> You can still get spare parts for 1950s cars. That doesn't mean they are
> flawless or not obsolete.
>
> Let's rephrase it. You have a system running on DEC PDP-11s: The guys
> who wrote the software are dead, the company that supplied it went out
> of business years ago, and no one will even offer a support contract on
> it, But it runs your trains perfectly.
>
> To replace it, a large software company quoted you $5m.
>
> What do you do?

You should make the senario closer to actual reality.

To replace it, the low bid software company has quoted $5m and two
years work to replace it, but you know from past experience with the
"low bid" winners of all prior projects that this actually will mean
~2x the quoted time and ~2x the quoted budget, so you are really
looking at a 4-5 year timeframe and a $5-6m budget overrunn for a total
of $10-11m to replace.

And your yearly budget line item allocated to system upgrades is $1m
(so we are talking a minimum of five years of your budget line item up
to eleven years of your budget line item).

And your choices are "accept" and "reject" (as you are far enough away
from the procurement process inside the bureaucracy that there is no
"negioate" available to you in any way).

On 2024-04-17 09:19, Lawrence D'Oliveiro wrote:
> On Tue, 16 Apr 2024 20:29:52 +0100, The Natural Philosopher wrote:
>
>> On 16/04/2024 14:39, Marco Moock wrote:
>>
>>> I love playing around with such things, but I wouldn't like to have a
>>> production system relying on it.
>>>
>> They were extremely reliable ...
>
> Floppies were not reliable. Prior to getting my first CD writer, I backed
> up my important programs onto two sets of floppies. Came time to move to
> CDs, I discovered read errors--on both copies of the same disk! Luckily
> they were in different files.
>
> When you bought some new software that came on floppy, the immediate wise
> thing to do was to make a working copy and use that. And keep the original
> away somewhere safe.

Floppies made in the 80's were quite reliable, they very seldom failed.
Floppies made somewhere in the 90's, failed a lot.

I don't know why.

I had backup sets of a hundred floppies with only a single recoverable
error (with pctools backup).

--
Cheers, Carlos.

On 2024-04-17 09:21, Lawrence D'Oliveiro wrote:
> On Tue, 16 Apr 2024 23:15:49 +0200, Carlos E.R. wrote:
>
>> On 2024-04-16 21:31, The Natural Philosopher wrote:
>>>
>>> The modern sneakernet equivalent is an SD card or a 'thumb drive'
>>
>> Also a nasty attack vector.
>
> Not sure an SD card can do that, but a USB device, yes.

Yes, I meant USB thumb drives, not cards.

>
> Hence devices like this <https://github.com/robertfisk/USG/wiki>.

Oh!

--
Cheers, Carlos.

On 2024-04-17 10:16, The Natural Philosopher wrote:
> On 17/04/2024 04:27, Lawrence D'Oliveiro wrote:
>> On Wed, 17 Apr 2024 04:45:43 +0200, Carlos E.R. wrote:
>>
>>> On 2024-04-17 02:42, Lawrence D'Oliveiro wrote:
>>>
>>>> On Tue, 16 Apr 2024 14:11:05 +0200, Carlos E.R. wrote:
>>>>
>>>>> On 2024-04-16 00:09, Lawrence D'Oliveiro wrote:
>>>>>
>>>>>> The trouble with “if it ain’t broke, don’t fix it” is when you wait
>>>>>> until it *is* broke, and only then discover that you have no idea how
>>>>>> to fix it.
>>>>>
>>>>> You don't replace an industrial setup worth millions just because the
>>>>> computer is "obsolete".
>>>>
>>>> If you could really afford to spend millions on the hardware, then it
>>>> would be peanuts by comparison to add on a software support contract
>>>> that will provide maintenance and updates for the expected life of the
>>>> hardware.
>>>
>>> Which probably they have.
>>
>> Then the computer is not “obsolete”, if you can still get support for it.
>
> You can still get spare parts for 1950s cars. That doesn't mean they are
> flawless or not obsolete.
>
> Let's rephrase it. You have a system running on DEC PDP-11s: The guys
> who wrote the  software are dead, the company that supplied it went out
> of business years ago, and no one will even offer a support contract on
> it, But it runs your trains perfectly.
>
> To replace it, a large software company quoted you $5m.
>
> What do you do?

Even if they used IBM PCs, the company still exists, they have the
schematics, and there are still people alive from that time. You buy
trains that are computer controlled. The trains are expected to run for
well over a decade, they are very expensive. So are the computers.

Getting spares for the trains is easy. Getting spares for the computers,
no. Obviously, replacing the entire trains is ridiculous.

Instead of trains, it can be any industrial thing. A factory making peas
preserves (a computer stamps the date, for instance). Anything that uses
machines controlled by computers. You can not replace the computers
every five years. The office may, the machine shop can't. Not profitable.

--
Cheers, Carlos.

On Wed, 17 Apr 2024 09:16:07 +0100, The Natural Philosopher wrote:

> You have a system running on DEC PDP-11s: The guys
> who wrote the software are dead, the company that supplied it went out
> of business years ago, and no one will even offer a support contract on
> it, But it runs your trains perfectly.

If you could really afford to spend millions on the hardware, then it
would be peanuts by comparison to add on a software support contract that
will provide maintenance and updates for the expected life of the
hardware.