Maybe there were real technical reasons why data MD drives never caught up (too much cpu power required to handle the data ?) ..
MO is the bottom-center disk in this photo https://kalleboo.com/linked/90s-disk-formats.jpeg
Apparently they were reliable but godawful slow, and he was glad to move onto SmartMedia and CompactFlash cards.
The technical reason why MD Data never caught on is the same reason why Iomega Zip and all the other superfloppy formats failed: none of them beat the CD on storage density and media cost. By the time the market actually needed a successor to 1.44MB floppies, everyone also had internal hard drives, so a lot of the use of the floppy drive was to install software. The fact that CDs couldn't be written to (yet) didn't matter. The fact that they held 650MB made them mandatory equipment, while every other rewritable medium was just a luxury for professional users working with a lot of data. And CD-Rs and RWs killed that last niche, too, even though they were less convenient[0] than superfloppies were.
[0] Writable optical media is a bit of a hack, necessitating processes like "mastering" and "finalization" to try and make the writable disc look like a regular disc to drives and players that aren't aware of the rewriting process.
I wouldn't say Zip didn't catch on, there were a few years where Zip drives were pretty ubiquitous. MD Data had a price problem. The drives were expensive ($500+) and the disks were nearly $30 IIRC. Meanwhile a Zip drives and disks were half that or less.
On the whole they just did not offer enough storage over competitors to justify their price. When CD writers got cheap they were better in almost every way.
The end result was Sony always seemed so schizophrenic with storage formats. They'd come out with a format that looked cool on paper but then have some artificial limitation (including stupid prices) that made it unattractive.
This goes into just 6 of the media formats, but there are so many more.
https://www.slashgear.com/1675900/discontinued-sony-formats-...
A more recent example: Archival Disc https://en.wikipedia.org/wiki/Archival_Disc
The emulator (which seems like it's for DOS) seems a strange thing to include on the disc:
><fs> file /ddman.exe
MS-DOS executable, MZ for MS-DOSAnyway… that was a preamble… in 2001 I spotted some of these in a weird shop in London near Russel Square. They had a sticker price of £150 which I thought was absurd. In one of my very few attempts to haggle in my life, I offered £50 and the shop attendant turned me down flatly. I was mildly disappointed because they were so brazenly “alternate timeline cassette futurism” (before the latter term existed) and the thought that I’d missed a golden opportunity gnawed at me for years. At some point in 2002 or 2003 I went back, but the stock had gone. I doubt they sold any of them at that price in that age.
Anyway, I probably dodged a bullet. They looked cool though.
* https://en.wikipedia.org/wiki/Sony_Multimedia_CD-ROM_Player
There are a couple of YouTube videos showing the device (filmed both around launch and more recently).
(I'll try to add some more context in a follow-up comment.)
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[0] a.k.a. "Sony Bookman" a.k.a. "Sony Multimedia CD-ROM Player" a.k.a. "Sony PIX100" a.k.a. "Sony Corporation Programmable CD ROM Player".
It turns out the data associated with MindMaze (& other encyclopedia data) changed storage format over subsequent releases of Encarta and these changes provide some interesting historical insights--including that if MS had had its way we'd all be writing web pages in RTF rather than HTML[1]. :D
You may ask, "What connection does this have to the Sony MMCD?".
Well, one of the storage formats used with early Encarta data is `.mvb` which is a format used by Microsoft Multimedia Viewer[2] (also known by multiple other names--none of which are any easier to web search :D ).
And, it turns out, "Multimedia Viewer could compile titles for Tandy Video Information System and other Modular Windows systems, as well as Sony Multimedia CD-ROM Player, a portable MS-DOS-based CD-ROM XA reader released in 1992."[2][3]
According to my research the tool "...includes software tools that simulate the look and feel of the Sony player titles on a PC" which is interesting in the context of the emulator for the Discman mentioned in the original post.
Anyway, that's the very short version of the rabbit hole--maybe in another five years I'll get around to writing up the rest...
Oh, just found my original tweet thread (including screenshots) about this rabbit hole as it happened[4]: https://xcancel.com/RancidBacon/status/1401009436949237763
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[0] https://en.wikipedia.org/wiki/Encarta_MindMaze (New as of October 2025.)
[1] https://en.wikipedia.org/wiki/Blackbird_(online_platform)
[2] https://en.wikipedia.org/wiki/Microsoft_Multimedia_Viewer (First added some time after my ~2021 research.)
[3] The Tandy VIS being a "Modular Windows" system is also of historical interest and FWIW has some support in MAME.
[4] Including screenshots of "Modular Windows Shell" and various "Multimedia Viewer" versions running under WINE.
I suspect the problem with the Data Discman was weak multimedia capabilities, compared to the what can fit on a CD-ROM, in either its API or what the hardware could push. If the software of the Data Discman had been more like Microsoft Encarta, it might have wowed people.
0, https://meta.wikimedia.org/wiki/Data_dump_torrents#English_W...
But I mean considering Wikipedia pages are so small, and Internet so cheap. Why?
The Data Discman fascinated me ever since I first saw mention of it in a magazine. This was the early 90s so CDs were still Brobdingnagian compared to other storage media at the time. A portable device that could carry an encyclopedia? Amazing! To me at the time they were a Star Trek technology made real.
As an aside I still love Sony's consumer electronics industrial design from the 90s. It was a great intersection of functional and attractive.
There is authoring software available at http://www.robotsandcomputers.com/computers/dd8h.htm to create compatible CDRs full of books assuming you can find some blank Mini CD-Rs or CD-RWs.
neat devices, Sony was always ahead of the time
The original Electronic Book format had many extensions: EB was Japanese-only, EBG added English, EBXA added PCM audio, EBXA-C added Chinese, and finally S-EBXA added color.
Looks like they were still selling a S-EBXA model in 2006: https://www.sony.jp/products/Consumer/DD/Dd/index.html