Re: Legacy computer in embedded industial systems (Re: Oh Gods ...)

On 8/23/26 14:28, Lars Poulsen wrote:
> On 2026-08-23 06:31, The Natural Philosopher wrote:
>> On 23/08/2026 14:20, Lars Poulsen wrote:
>>> On 2026-08-23 04:32, Carlos E.R. wrote:
>>>> On 2026-08-23 08:57, c186282 wrote:
>>>>> On 8/22/26 18:35, Lawrence D’Oliveiro wrote:
>>>>>> On Sat, 22 Aug 2026 08:36:42 -0400, TJ wrote:
>>>>>>
>>>>>>> It goes against the grain, for me at least, to send perfectly good
>>>>>>> running hardware off to the recycler, just because it is
>>>>>>> "experienced."
>>>>>>
>>>>>> CPU generations (and entire architectures) get dropped from the Linux
>>>>>> kernel because they can’t find anybody to step forward and maintain
>>>>>> the support for them.
>>>>>>
>>>>>> That is how they tell that there are so few instances of those
>>>>>> particular kinds of hardware around, that essentially nobody cares
>>>>>> about them any more.
>>>>>
>>>>>    Sad, but quite correct.
>>>>>
>>>>>    Really not much call to run Linux-ish stuff
>>>>>    on a 386/486 these days. How many people
>>>>>    still USE those old boards for ANYTHING ?
>>>>>
>>>>>    MAYBE a few "industrial" monitor/control
>>>>>    systems ... but REALLY they oughtta upgrade.
>>>>  > >    However SOME won't because it might cost a
>>>>>    few dollars. They'll run the old hardware
>>>>>    until it literally bursts into flames - and
>>>>>    then be SCREWED for days/weeks/months. But,
>>>>>    the bean-counters will TELL them they're
>>>>>    saving SO much money, now .......
>>>>
>>>> Industrial computers may have boards, like data acquisition boards, 
>>>> to interface with motors and sensors (or cameras). If you upgrade 
>>>> the computer, it comes with a new operating system, so their 
>>>> expensive software does not run on it. The cards probably can not be 
>>>> plugged in, so they also need replacing; the new boards will 
>>>> probably not be compatible with the expensive software. So finally 
>>>> they need to recreate the software (hopefully the company that 
>>>> created it still exists and has the source files). And maybe there 
>>>> are a bunch of computers to replace.
>>>>
>>>> The price is no longer minor.
>>>
>>> What you have to do is make sure you have one or two backup hardware 
>>> packages, because when the computer breaks, you won't be able to buy 
>>> one that works. (Just try to find a motherboard with ISA slots today!)
>>
>> https://www.directindustry.com/industrial-manufacturer/isa- 
>> motherboard-255106.html
>>
>>> And with custom plugin boards, it is kinda too late to have them 
>>> fabbed when the system is already down. And fire it up once a year to 
>>> make sure it still runs.
>>>
>>> That may not guarantee that you can recover, but it vastly increases 
>>> your chances.
>>>
>>> And when you put the reserve system into service, it is time to 
>>> expedite developing a replacement!
>>>
>>> For PC systems, the big hurdle is that old 16-bit systems allowed
>>> programs to do I/O to ISA bus peripherals without kernel programming, 
>>> device drivers and OS hooks. When you "modernize" that ability is 
>>> lost, and you have to rebuild with much more complicated programming.
>>>
>> That is a function of the operating system, not the chipset
> 
> Good luck finding a motherboard with ISA bus slots. 
 >

   Yea ... threw out my last ISA-bus boards a
   long time ago. Everyone did. Maybe a bit
   short-sighted ........

> For a very long 
> time, motherboards had ISA bus parallel ports and serial ports, where 
> all you had to do to access them directly was to populate the footprint 
> for the connector. I think those went away around 2018.
> 
> I got a handful of machines with footprint for a legacy parallel port as 
> refurbs after corporate desktop replacement rounds, and brought them to 
> my PCB rework guy. I was very disappointed to learn that the PCB 
> manufacturer had reduced the footprint from 2.5 mm pin spacing to 2 mm 
> pin spacing, making the ribbon cables used for this application not fit.

   You MIGHT be able to find add-on, maybe USB, adapters
   and drivers that WILL properly emulate parallel/serial
   ports from the old days. There ARE cheap dongles to
   fake 9-pin serial ports, but haven't seen any of late
   that'll do the older 25-pin ones. If you're next level
   you could MAKE them with microcontrollers and hand-made
   drivers (TOO old now to get that deep in again).

   The huge old "wide"-Centronics printer interface, good
   fuckin' luck. Too bad, had a great old Epson wide
   pin-printer with that interface - slow but insanely
   reliable, went through endless giant boxes of the green-
   stripe wide paper without a glitch.

   As for pin spacing .... built a bunch of devices on
   the old Rabbit-II boards. Rabbit-III boards went from
   3mm spacing to 2mm spacing - too tiny for mere humans
   to work with conveniently with ordinary dremel-presses
   and soldering irons.

   Sad, the Rabbits were GOOD boards (STILL sold BTW)
   but had to drop 'em.