Section 1: Background Information

1. Where can I find out more?

 Grab the alt.cdrom FAQ from rtfm.mit.edu (does this still exist? I cannot find it -Mike); it has a great deal of general information about CD-ROM drives. If you are interested in seeing the technical innards, Linux source is one route:

"You could look at the linux CDROM file system sources, they're available on tsx-11.mit.edu and AFAIK it fully implements the ISO format with rock ridge extensions. "

[courtesy <pmcgw!uunet!eyrie.demon.co.uk!df> (Derek Fawkus)]

Toshiba has specifications for its drives available for $15 if you want to write a Toshiba driver yourself.

[courtesy rkling@austin.intel.com (Ralph Kling)]

2. What are the relevant newsgroups?

If you have an additional questions, please post to comp.sys.sun.hardware. The FAQ maintainers put everything they know in the FAQ!

3. As as overview, what are my options for using a CD-ROM on a Sun?

You can purchase a SunCD or SunCD+ from Sun, a reseller or used. Pros: this guarantees you almost complete compatibility for booting and mounting typical data CDs and audio CDs on a wide range of Sun hardware. Even if your PROMs are not aware of CD-ROMs, you can fool them into recognizing the CD as a boot device. Cons: the drives are neither the fastest nor the least expensive, to say the least. You are restricted to 512 byte/block mode, so the drive cannot be used on a Mac or PC without special software.

If you don't want to go the Sun route and want to be able to boot from the drive, you must get a CD that has Sun-compatible PROMs available, a DIP switch or some hack (such as the Toshiba method outlined above) that allows you to switch from 2048 byte/block mode to 512 byte/block mode. If you want to be able to mount discs, you can usually patch the kernel so it will recognize 2048 byte-format discs.

Either way, keep these caveats in mind: 1) SunOS 4.1.x has SCSI ID 6 hard-wired into the kernel, so if you try to mount or boot from any other location it will fail. 2) only SCSI-2 drives will work, period. 3) unless you purchase a $400+ third-party SCSI driver, many of the advanced multimedia features (multisession XA discs, multisession PhotoCD discs, direct digital sampling) will be out of reach. Solaris 2.2 supports multi-session CD access, but only with the SunCD+.

4. What drives have been shown to work?

(See Sun compatible CD-ROM drives)

5. What is doomed to fail?

 I culled these stories from the bleeding edge of alt.cdrom and other sources. If you know the cause of the problem or have succeeded with these copies, mail a solution to the listed address and cc: a copy to me so I can add the solution to the FAQ

Configuration: Sun 3/80 + any CD

Courtesy: uunet!cs.bham.ac.uk!A.H.Speedie-SE0 (Andrew Speedie)
Comments: no success at all. Can somebody confirm?
Update: Craig Dewick, (cdewick@jedi.apana.org.au) has managed to get SunOS 4.1.4 install tar files from a modified Toshiba 3301 "when it was a 3/480 running SunOS 4.1.1u1, which was the same Sun-3x kernel release as a 3/80 would use". This may or may not be useful as Craig also mentions that the 3/480 and 3/80 use different SCSI chips (the 3/80 has an Emulex ESP chip, and the 3/480 has a VME SCSI card with an NCR 5380). This may or may not matter. I think we're still looking for info about this.

Configuration: NEC CDR-73 on Sun-3

Courtesy: pmcgw!uunet!burrhus.harvard.edu!ddl
Comments: generated so many SCSI errors that it corrupted the hard drive; using SCSI-2 and SCSI-3 host adaptors. Another caveat from ishikawa@ds5200.personal-media.co.jp (Chiaki Ishikawa): turning off the CD-ROM during operation causes disk errors.

Drive: Toshiba XM-3201B

Courtesy: mfrisch@saturn.tlug.org (Mike Frisch)
Comments: This drive does not appear to have the same PCB as the 3301/3401 and thusly cannot be modified in the same manner. I'd be interested in something confirming whether or not it's possible to modify this drive to a 512 byte sector size.

Configuration: AppleCD 300 Plus on older SPARC PROM

Courtesy: Blake Wright (bmwright@smeg.users.xmission.com)
Comments: "This drive wasn't a Sony but according to the Apple specs it did all the same block sizes as the standard 300 and also accepted the block size change command from the SCSI bus so it should have worked. Had no luck at all with this. I tried it on an IPC with an older boot PROM (v1.4 or v1.6 if I recall correctly) that only supported the "boot sd()" syntax and not the "boot cdrom" command.". It is suspected that the older SPARCs which do not natively support the "boot cdrom" command do not issue the proper SCSI sequence to change the CD-ROM sector size.

Configuration: Apple CD600i

Courtesy: John Armstrong (siberian@west.net)
Comments: "Initially it reads the disk fine(I get a spinning cursor as the drive accesses) then I get a series of messages about data transer overun and some statistics. So, overall, it looks like the Apple CD600, while a Sony Drive, doesn't support the MODE switching."

Add more or correct any of these reports, please!

6. How do I know if my CD-ROM is not natively Sun compatible? What error message is displayed?

It is reported that the PROM will report a "bad magic number" when it attempts to boot from a 2048 byte/sector CD-ROM drive. All is not lost, though, see Chapters 3, 4, or 5 in this FAQ.

7. What are the specifications of the SunCD/SunCD+/SunCD2+/SunCD4?

The SunCD is a repackaged Sony CDU-8012, while the SunCD+ is a CDU-561. Both are the versions with 512 byte/block functionality, but they support a MODE SELECT command to change mode from 2048 to 512 if so configured.

The SunCD2+ is a dual speed CD-ROM for use with the SS4 (Sun part number X661A/C6/internal version) or SS5/SS20 (Sun part number X578A/C6/internal version)

The SunCD4 is a quad speed CD-ROM. SunExpress lists three versions of this drive in their latest catalog: 

Sun part number       	Description
-------------------------------------------------------------------
X6153A/C6		SunCD 4 CD-ROM Drive for Ultra 1 Systems
X6151A/C6		SunCD 4 SPARCstorage UniPack 68-68pin Cable
X6152A/C6		SunCD 4 SPARCstorage UniPack 50-68pin Cable