FWIW I went looking on archive.org and found "ERIC ED378962: Developing CD-ROMs: Pitfalls and Detours on the Road to the Digital Village." which had a very brief mention of High Sierra:

https://archive.org/details/ERIC_ED378962/page/n13/mode/2up?...

There are also a number of High Sierra format CDROMs on the archive.

From "The PC Programmers Sourcebook" (https://archive.org/details/f15_the_pc_programmers_sourceboo...):

Has section: "5.064. HIGH SIERRA CD-ROM DIRECTORY FORMAT"

Includes a table of the details.

Also adds:

"Note: High Sierra and ISO 9660 formats differ slightly:

- Two fields changed position.

- All date and time fields have an extra byte In ISO 9660 to describe the 15-minute offset from GMT."

"Source: MS-DOS Extensions (Microsoft Press), page 96

The Ins and Outs of ISO 9660 and High Sierra," Develop, July 1990"

Life before the web, eh...

This "CD-ROM Professional 1990: Vol 3"[0] (https://archive.org/details/sim_eventdv_1990_3_0/page/n63/mo...) publication has some interesting historical trivia:

* "At the slow pace with which NISO was proceeding (in nine months it still had not even named a committee), and with the historical knowledge that standards organizations take from three to five years to develop a standard, a meeting between Xebec and Reference Technology was held in August of 1985. At this time it was agreed to approach other participants in the industry to see if there was interest in convening an industry group to expedite the formation of a logical format standard. In October of 1985 representatives from the major CD-ROM industry participants met at the High Sierra Hotel in Lake Tahoe and agreed to cooperate in formulating a logical format standard.

From this meeting the ad hoc group was formed and became known as the High Sierra Group. John Einberger of Reference Technology was selected as chairperson.

From December 1985 through April 1986 this group met five times and completed a final draft proposal in May 1986. In June 1986, this proposal was presented to NISO and the European Computer Manufacturers Association (ECMA). In January 1987, the approval activity was passed on to the International Standards Organization (ISO) which performed its final edit in October 1987."

* Article: "HIGH SIERRA VS. ISO 9660: A SUMMARY"

* "NISO's first foray into CD-ROM is Z39.60, a standard for the volume and file structure of CD-ROM (and, potentially, other optical media). This standard is much better known as the High Sierra Group standard."

[0] "CD-ROM Professional (formerly the Laserdisk Professional)" :)

> Z39.60

I saw that and thought, isn't that an old library catalogue protocol?

But that was Z39.50:

https://en.wikipedia.org/wiki/Z39.50

Heh, funnily enough, I have some vague memory of doing some Z39.50-related Python development back in the early-mid 2000s when I worked for a local library.

I remember an old SGI workstation which used a custom filesystem for the CD's: cdromfs. Don't know if they can be read on modern OS's.

SGI uses EFS on their CDs. It's basically the same filesystem they used on harddisks before XFS (in the IRIX 5 days)

Yes. I think my memory may be failing. I'm almost sure I remember having typed mount and seen cdromfs on the list. Maybe it was cdfs (https://nixdoc.net/man-pages/IRIX/man4/xfs.4.html) and mixed things.

IIRC there were some filesystem a designed to support “appending” to but able CDs - joliet maybe was one of them - and cdromfs maybe have been related.

I remember I converted CDs to/from EFS with a shell script. It wasn't complex, but I don't remember the details. Something with an offset?

TIL: people had CD-ROMs in the 80s! Wow. I didn’t see a CD-ROM until probably 1994…

You might enjoy this 1985 episode of The Computer Chronicles focused on optical storage:

https://youtu.be/5TcsOgy9weg