So, I dug it up. Mine is a Pioneer DVD-305S, a SCSI 10x/40x DVD-ROM in the usual form factor with a 50pin scsi connector. I set the 512byte blocksize jumper.
Attachment:
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I attached it to an Indy running IRIX 6.2. The Indy will boot from an original IRIX CD just fine (I didn't try audio).
IRIX reports:
Code:
# scsicontrol -i /dev/scsi/sc0d6l0
/dev/scsi/sc0d6l0: CD-ROM PIONEER DVD-ROM DVD-305 1.03
ANSI vers 2, ISO ver: 0, ECMA ver: 0;
Response format type 1, but has SCSI-2 capability bits set
supports: synch linkedcmds. inquiry format is SCSI 1
Device is ready
But, and this is where it gets interesting: it also boots
IRIX DVDs. Yes, and that's no a typo!
First, I used a PC with Nero to burn a 'dd' image of an IRIX 5.3 CD to a DVD. This boots just fine, just a lot quicker than you're used to from 'Indy vintage' external CD-ROMs

Encouraged by this initial success, I added a second (4.5GB) disk to my PowerIndigo2 and 'dd'-ed the first IRIX 6.2 CD onto it. I then used fx to grow the partition to the size of the actual harddisk, changed the partition type back to 'sysv' (?) and used growfs to grow the EFS filesystem. Next, I copied the second IRIX 6.2 CD into this filesystem, unmounted it and 'dd'-ed the entire harddisk to my server where I burned it to a DVD.
This boots too!IRIX reports:
Code:
# df -k
Filesystem Type kbytes use avail %use Mounted on
/dev/root xfs 4329525 1306802 3022723 31 /
/dev/dsk/dks0d6s7 efs 4410288 805355 3604933 19 /CDROM
As far as IRIX is concerned, this is just a
very large CD-ROM. And it seems it doesn't care, as long as the device utilizes a 512byte block size. Somehow, this was to be expected since you can perform similar hacks using a harddisk.
I am quite excited. Imagine an entire IRIX distro including all patches etc. on one or two DVDs. I've only used systems and software from well before the DVD was invented so this hack is completely transparent
Oh, there are some thing that don't work:
* UFS. This would require modifications to IRIX. Think of this as a large EFS CD-ROM
* DVD video. Ditto.
* You may need IRIX 6.2 to make one, I believe IRIX 6.5 has read-only EFS support
* My PowerSeries doesn't want to boot from the Pioneer, either from a CD or DVD. I tried with the 4D/440VGX which has PROMs that are new enough that they recognize a CDROM (doesn't need those 'I'm a harddisk' hacks).
* I didn't try dual layer DVD, and I don't even know if the Pioneer supports them. There's an upper limit of 8GB to EFS filesystems.
Have fun

_________________
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