Just begin. You don't need an inventory. Just start by dividing them into piles on the floor, organized by role.
The biggest piles can get further subdivided into more-specialized roles.
There will be piles that consist of memorable cables that have interfaces you haven't used in years. Segregate these unicorns; they'll be handled with special care later on.
After that, you've got a broad selection of current-vintage stuff that is in active use -- all laid out before you. So just spend a few minutes to pick out a few nice examples from each remaining pile. A few cat5-ish cables of various lengths. Some AV interconnects of different descriptions. A few universal power cables: IEC, figure-8, and Mickey Mouse. Pick out the very best of the USB cables, and of the SATA cables, and whatever else you're making use of in 2026.
Wrap each of those selections up neatly and put them in appropriately-small boxes. Label each box by role. Put each of these boxes away somewhere that is both out of the way, and able to be quickly returned to later.
That was easy.
The remaining piles on the floor are just scrap. Make a plan to scrap them and package them appropriately. Put that package near the front door.
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Now we get to the really fun part. All those precious historic artifacts that were carefully isolated before? It's time to sort those.
Who knows when a 24-pin dot matrix printer could turn up that you need a DB-25 to Centronics cable for testing with, or you might find a use for the 15-pin PC joystick splitter? That PSX controller extension was hard to find even when it was new.
It's all very important stuff with very specific roles. It's not like any of these things are being made in factories every day anymore. And it all has history.
So take a photo of this amazing collection of vintage cabling, and then package it all with the reverence and care that it deserves. After that, simply put that package near the front door with all of the other scrap cabling.
Nothin' to it.