There is a small business near me that has a wool testing machine that absolutely relies on custom DOS 3.3 based software and an old school serial card. They h

There is a small business near me that has a wool testing machine that absolutely relies on custom DOS 3.3 based software and an old school serial card. They have had to become very astute at picking up old parts to keep their old rigs running as the guy who wrote the control software passed on, and they don't want to invest money in rewriting it. You would think commodity hardware would run this setup but all attempts at shifting it have failed. The problem with old electronics is that once the chips fall out of fashion, you are never getting replacement parts. Does anybody still manufacture DDR2 ram for example? Its just not that long ago it got replaced by DDR3 and DDR4 but in 10 short years if you need a couple of sticks of it, your only option is 2nd hand. The e-waste issue is very real and the relentless pace of change doesn't help, but I don't have a good answer for solving it.