Newly-minted SC-55 owner here. Got various questions.

I daily-drive a 10-year old PC with no MIDI or joystick interface. The newest discrete sound card I have in a pile is an EMU10K-powered (terrible digital resampling) CT4780 SB Live!, think I could get the MIDI interface on that play ball with Windows 10?
Then there's the fact that I can't find my MIDI cable, I haven't touched it in 15 years, I've moved twice since then. Used to hook up my Yamaha keyboard and Digitech effects processor to my PC though it, so I definitely have one, somewhere. Should be in a box of other legacy data cables, serial and parallel, which I did not find today. Might be in the attic at my parents' place. For my retro rig I'll need to find it, but for now I think I would like to own a USB MIDI interface for my newer computers... Which one to get? Best? Cheap?

So, my SC-55. It's a mk1 with the GM logo on the front. Not sure if there is a sound difference between versions for PC games. I have opened it and replaced the leaked CR2032 coin cell, doesn't look like it reached the board, I cleaned up the battery holder with IPA. It powers up and the display lights up with Piano instrument with the Roland 1A 9V wallwart, the display did not light up (but buttons did) with another 9V 350mA wallwart, so 500mA like it says on the unit should definitely be the minimum. The Roland wallwart looked unregulated to me, so out of curiosity I measured it with a multimeter with no load, sure enough exactly 13V DC. Which brings me to the idea/desire that I had. I want to power as many peripherals on my desk directly from the PC, so I'm wondering if I can power my MIDI modules from the regulated 12V of the ATX PSU. I looked in the SC-55 user manual but it does not list an acceptable range of "absolute limits" in datasheet style. Since an unregulated wallwart can supply voltages as high as 13V, like I measured, I'd like to think that 12V would be okay, just not sure about continuous use. Anybody know?
Or should I investigate the circuit to see what internal regulation it has...? Well, I kind of did. So that's a 78MR05R voltage regulator, and the main electrolytic cap is 16V. Recommended operating conditions for the regulator are 7.5 to 20V. So anybody else do anything similar?

Yes, I'm aware of the polarity of the power jack on Roland equipment. Ring is positive.

This:
https://www.amazon.com/Roland-UM-ONE-MK2-MIDI … /dp/B00967UN50/
VS this?
https://www.amazon.com/NUOSIYA-Interface-Indi … /dp/B08CXJYQC8/

Any difference?