Seems you have a large house... Or is it a warehouse?Somewhere I still have a B&W PowerMac G3, and a grey PowerMac G4 (which I used regularly right up until 2009 - now *that* was a solid machine -- and probably *still* works if I bother to dig it out and set it up...), both of which have SCSI inside, but I don't have the right cables, and some of the SCSI HDDs I want to recover data from are not Mac formats - and not all of them actually power up anymore. (I have some PC, some Linux, some Mac, and several Amiga drives, including 4 Syquest removable platters -- all of which I want to recover stuff off of eventually...) But as I said, I'm not sure it's worth the time and effort to get them working again, or the money to find the right cables.
If drives don't power up anymore, you're pretty much screwed. Even exchanging boards only work for identical models.
Cables, have you looked there?
Startech
DX.com
There are SCSI cards, but pricey.
Are Archival Gold type discs available as DVD+R from all major brands? Or is it a brand in itself?Well, I'm mostly concerned with 10-20 year timeframes, so for work, I've been using Archival Gold discs in normal burners - and I tend to make multiple copies, and store them in different physical locations.
For longer term stuff, if you need it, as you pointed out, 50-100 year manufacturer claims simply aren't testable, so I'd make even more copies, and set up a review and renew program - where you set up a plan to review the media after a period of time, and recopy it to new, more modern, media periodically. You can never have too many copies of data, IMHO.
You CAN have so many copies it simply takes way too much time tor even periodically review them.
E.g., do you seriously expect to need a document so old you don't even remember you created it? I'm not talking about job-specific requirements, such as keeping raw experimental data for 20 years or more.
So I personnaly keep a number of copies proportionally to data's importance, which, so far, happens to be inversely proportional to its size. Downloaded movies exist in just one copy, music collection, virtual machines and hard-to-get application get two (mainly as a safeguard against VirtualBox fussiness), documents have three, and experimental data have five.
Incidently, none of these is located on optical media since I have never found a unified way to catalog all that. How do you manage versioning on optical media / hard drives in the "meat" world?
Storing on the net is just a cheap way to get physical separation. I learned the hard way that when the most recent version of a file is stored online, but the provider is experiencing issues... You're pretty much screwed.(There will always be some kind of archival media being produced despite people who think everything will be stored on the net - because there will always be a need to archive huge amounts of data. Our ability to produce large quantities of data is increasing just as fast, if not faster, than media capacities, and definitely faster than network speed increases, and I honestly don't see that changing any time soon...)