All this is kind of strange. Many, if not all of you are in the manufacturing business in some form or another. The concept behind any company is to make money. People work to make money. If you are lucky you may be able to save/invest some of that money. WHY? To make more money.
Why do companies change things so often? MS was mentioned, since its one of the largest companies in the world (I read the Fortune 500 mag while at the doctors office...can we complain about having to sit forever waiting at a doctors?) MS is a company that wants to make money, how do they do that? There business (for that matter all businesses) isnt based on other companies but something called "consumers". Any way you look at it a company that doesnt sell directly to consumers sells products, machinery etc to other companies that do make products for consumers. Consumers are never satisfied, with old or new.This thread proves that. History shows us that things never stay the same. Consumer demands make things obsolete.
As far as things like MS not supporting DOS anymore, why should they? There is no profit, WHY? Because it can be obtained free.
http://www.freedos.org/
As for AB not supporting older products, that would be a business choice I guess but think about it a little. They build a device and it was installed on a machine and work fine for what? may 20 years..lets go less..10 years. The first year they offered support if needed but in many cases it wasnt so the support contract was never renewed. OK now 10 years later there is a problem with the machine, no software is available, no support contract but its expected that the company should provide at no cost. I do not get this.
I will use a simple example. How many of you have a Washing Machine in your home? Many people do. Many of these machines are kept and run for 10 to 20 years. I bought one back in the late 70's that is still being used by a family member.(one of those it got passed around thru different family members to family of theirs etc). My point being, Maytag, Kenmore, Whirlpool, GE etc doesnt have to provide things for their washing machines after 10 or 20 years why should anyone else be expected too?
As for support contracts (this part applies to what is done is US, not sure if happens in other countries). When was the last time you bought an appliance or electronic device from KMart, Walmart, Sears, Best Buy or any place that they didnt immediately ask you if you wanted to PURCHASE the extended warranty?
Overall when it comes to PLC's and the software I would agree it would be easier for us if some things were done differently. The fact is that in most cases its not our money thats involved its a companies investment and their decision whether its needed or not.
I just dont see where its an issue for engineers/techs, the changing is what creates our jobs. If it never changed then everyone would eventually be able to do it and many of us wouldnt have the jobs we have today.
End of ramble.
If you have a need for older used PLC components then you may want to checkout
http://www.plccenter.com
They carry or repair many brands
IF you have a need for older motherboards or PC components then you may want to look at
http://www.pricewatch.com
When I sold PC's I used pricewatch to find the best deals on components. I have used ebay in the past to buy and sell items, plccenter/speck controls has bought from me and sold to me. They normally sell at 50% of retail so its possible to find good used parts at a decent price. I do not work for either company.