The thing I was working on came down to one long-odds try. I had three very obsolete versions of the data-compression widget, one much more obsolete than the others, and that was the only one that was working properly. That oldest version is larger and much more fragile; they're especially difficult to transport. You have to remove all the 14" square plug-in circuit boards from the mainframe, move it in pieces, and put it back together on the far end, or it will not be working; the card-edge connectors are delicate.
The particular example I had was once moved with the cards in it. Luckily it has a lot more slots than cards; with help from the manufacturer (it was still supported back then), I moved cards around, got it working, and decided never to move it from that location, ever.
"Never, ever" is about a decade long. Today, I took it back apart, moved it across town, and put it back together in a new location. So far, it's working. This is moderately big deal; I did not have high hopes but there were no other immediate options.
And that caps the last four days. I think I'll take the rest of the week off.
1 week ago