Here's a cheap and easy one: How do you record a MiniDisc if it's somewhere between the years of, say, 1998 and 2002 and your music is on a computer but NetMD hasn't been launched yet?
Strap in, because we're about to look briefly at some history and context. (I apologize so much, total read on this is 1312 words.)
TL;DR Sony sold a pack-in USB TOSLINK sound card for a couple of years, and then stopped the instant NetMD launched.
So, I'm not sure if I mentioned this or if it was just a given but one of the core properties of minidisc is you need a recorder of some kind. There weren't many pressed discs, and in theory Sony designed it as a replacement for the recording aspect of cassette tapes.
Except: Instead of recording your records to tapes, you were supposed to record your CDs to minidiscs, because it's the '90s now.
Most of the well-known and beloved Minidisc machines are recorders and of those almost all of them have a TOSLINK optical digital audio input. In 1992, the sell was this: You had a CD player in your hi-fi stack and it had TOSLINK output. CDs sound great but they're inconvenient to use on the go and look fragile. So, you buy a MiniDisc recorder such as the MZ-1, connect the digital audio output from your CD player to the digital audio input on your minidisc machine, put 'em in sync mode, hit record, hit play, and then come back in about an hour to your newly minted minidisc.
The MZ-1 was a relatively severe compromise in terms of quality, but Sony's bet was you'd love the idea enough to buy in and then in a few years upgrade to a newer machine with a better version of the compression algorithm. The MZ-1 was also an absolute chonkster so Sony was kind of betting on the idea of dedicated players. They built out the ecosystem with hi-fi decks, boomboxes, bookshelf stereos, and CD-MD dubbing decks.
In the late '90s Sony was trying to shift the focus of minidisc onto younger people and the way young people (millennials) at the time were getting and managing their music at the time centered around their computers. Sony wasn't going to say the quiet part (P2P) out loud but they knew there had to be a "good" way of getting audio from a computer onto a minidisc, for the new generation to be interested.
(We're ignoring here, for convenience sake, most computers from the time have a line out or a headphone out port and you could simply have used an audio cable to do this, it would have worked fine.)
In 1998, Sony partnered with Xitel to bundle some of their recorders with MD-PORT adapters. These are simpler than they seem: They're USB sound cards. The marketing point on the first one (the AN1, bundles starting in 1999) was "you can reduce line noise by using an outboard audio source!" The bundles had variant model names like MZ-R37PCIF and MZ-R55PCIF.
In 2000 just ahead of the MDLP launch, Xitel and Sony added a version with TOSLINK, an OEM'd version of the MD-PORT DG2, and changed the nomenclature slightly. This resulted in the MZ-R70PC and MZ-R70DPC, and later the MZ-R500PC and R5/7/900DPC. Other than labeling, the difference between the retail and OEM DG2s is a mode switch exists on the retail version.
The MD-PORT DG1/2 have a trick: With new enough MD recorders (the R70/90 and newer) and with software from the period, they add track marks automatically. Automatic track marking is A Big Deal, and should have made dubbing minidiscs and getting the minidisc technology advantage significantly easier without artificially adding 2-second gaps.
The idea was somewhat short-lived: Sony stopped selling these bundles, at least in the United States, the literal instant NetMD launched, possibly sooner. NetMD itself lets you load tracks faster and with titles over USB.
I haven't gone to look but I'm guessing this was a sore point with Mac users, who were already annoyed with the way Sony fumbled marketing, messaging, and support of the MD-PORT adapters.
The Xitel sound cards worked with both Windows and Mac (even though Sony didn't claim it) but NetMD and the ensuing discontinuation of all the non-NetMD portable recorders (except the R910...) meant there wasn't anything for Mac users. You could still go buy your own retail TOSLINK output and use the optical input on most of the recorders, but if you were a Mac user and you went out and bought a NetMD machine you were forced to leave most of the advantages of it on the table.
This situation didn't change until 2005 with the second generation of HiMD machines. Ahead of that happening, Sony made it even worse by introducing NetMD machines with no audio input at all.
(My apologies for belaboring this specific point but I was a Mac user at the time and I would've been very sad about this all had I been aware enough of Minidisc to ask for it, especially since I know my family's budget would have meant one of the Windows-only ultra budget models with no audio line input.)
... Anyway.
I haven't used these with any vintage setups, but on modern computers they're "fine" at absolute best. On Windows, the drivers for the MD-PORT DG2 (both versions) works extremely poorly and you have to fiddle for several minutes before it correctly enumrates. On Mac, iPhone, and iPad, it works fine up front. Friends who use Linux say they work fine there.
There's a few resources online that claim the DG2 has severe jitter issues and that may be true and you may notice if you have like 24-bit/192khz WAVs and are thousands of dollars into a giant hi-fi, but it's good enough for minidiscs. (and my PCM-D50, but more on that later...)
The track marking trick mostly doesn't work any more, with one single exception: VLC player on Windows. My theory is VLC on Windows unloads the audio driver between every track, causing the light to flash, which adds the track markers. All other modern audio players are either themselves web sites and can't drive audio hardware with that much granularity anyway or (I haven't tested for this but it would explain some things) are running their own comfort noises in the background.
My perspective is generally that by the time your audio is in VLC, you may as well use NetMD to load it, so I don't use the DG2 all that often. I do now have three of them -- an OEM one that's broken, a retail one that works and a working OEM one.
This isn't a "recommendations" post but I genuinely recommend a newer TOSLINK interface for anyone who wants to use optical audio to author minidiscs. Figure out some other way to do track marks, whether using one-at-a-time playback or just adding 'em in later and use a modern device with better drivers.
On the home deck side of things, Sony had been adding PC connection kits for a few years. These are basically serial control hardware that let software on the computer coordinate dubbing, but availability of those kits in the US wasn't particularly wide.
It also appears Sony was attempting to focus on the idea of someone whose only MiniDisc machine was a portable they used for recording as well as playback, possibly as part of its drive to reduce costs, especially with Sony's advertising in the US framing MiniDisc as a portability format, an adjunct to the CDs you use at home, or, well, those MP3s you found laying around on the side of the road. More on that later, though.