IRIX Network Forums
External SCSI CDROM drive - Printable Version

+- IRIX Network Forums (//forums.irixnet.org)
+-- Forum: SGI/MIPS (//forums.irixnet.org/forum-3.html)
+--- Forum: Beginners' Questions/Tips (//forums.irixnet.org/forum-6.html)
+--- Thread: External SCSI CDROM drive (/thread-2730.html)

Pages: 1 2 3


External SCSI CDROM drive - robbo007 - 03-01-2021

Hi,
Are all external SCSI CDROM drives compatible with the Octane2 system? I don't have a CDROM drive and was thinking of reinstalling IRIX as this is full of cad design stuff from the last user. I fresh install would probably be better. 

Thanks,


RE: External SCSI CDROM drive - weblacky - 03-01-2021

If your intention is to reinstall the operating system then the answer is no. Not ALL SCSI optical drives can reinstall Irix. But all SCSI optical drives will likely read normal Discs under Irix.

Irix (like many UNIXes) uses a trick to install itself over optical media. Is used a 512 byte block layout (like a hard drive of the same era).

So the optical drive (DVD or CDROM) but support 512 byte block mode (from the normal 1024).

Lots of drives have jumpers with 512/1024 on the back to indicate this. If the optical drive is branded SUN (for SUN Microsystems) it should support this 512 Mode as SUN Solaris had to use the same trick.

So hopefully that is clear. Many of the supported drives will be caddy-based. Tray & slot loading DVD drives are available that support this feature but less common. I’m told that for DVD drives to reload Irix you may wish to target certain Toshibas and slot-loading pioneers (HP SCSI rebranded slot loading SCSI drives may work as well).

No real guarantees. The safest bet is get an old 1X-2X caddy based SUN CDROM drive. It will definitely work without complaints. These drives used to be around a lot. However starting around 2013 most of the vintage peripherals started to be thrown away and become scarcer and therefor prices have risen dramatically. For an external SUN CDROM drive, expect around $100, for an internal SCSI DVD drives, expect around $60-$70.

Also drives can have old do belt issues and such. I’ve never had one of my SUN drives fail yet though. They are built like tanks. I’ve not looked too hard, but the community to provide new gears and belts is really in its infancy, so repair isn’t a good option right now.

Spend the money on a drive in known good shape, if you don’t want to risk it.

Also while I tend to reinstall via optical drive, many owners don’t want to bother and use a network based installation instead. If you’re buying this optical drive just to reinstall, I’d advise you to first look into the VMs available for doing network installs.

If you want the optical drive for other reasons, by all means go for it.


RE: External SCSI CDROM drive - robbo007 - 03-01-2021

(03-01-2021, 06:07 PM)weblacky Wrote:  If your intention is to reinstall the operating system then the answer is no.  Not ALL SCSI optical drives can reinstall Irix.  But all SCSI optical drives will likely read normal Discs under Irix. 

Irix (like many UNIXes) uses a trick to install itself over optical media. Is used a 512 byte block layout (like a hard drive of the same era). 

So the optical drive (DVD or CDROM) but support 512 byte block mode (from the normal 1024). 

Lots of drives have jumpers with 512/1024 on the back to indicate this.  If the optical drive is branded SUN (for SUN Microsystems) it should support this 512 Mode as SUN Solaris had to use the same trick. 

So hopefully that is clear.  Many of the supported drives will be caddy-based.  Tray & slot loading DVD drives are available that support this feature but less common.  I’m told that for DVD drives to reload Irix you may wish to target certain Toshibas and slot-loading pioneers (HP SCSI rebranded slot loading SCSI drives may work as well).

No real guarantees.  The safest bet is get an old 1X-2X caddy based SUN CDROM drive. It will definitely work without complaints.  These drives used to be around a lot.  However starting around 2013 most of the vintage peripherals started to be thrown away and become scarcer and therefor prices have risen dramatically.  For an external SUN CDROM drive, expect around $100, for an internal SCSI DVD drives, expect around $60-$70. 

Also drives can have old do belt issues and such. I’ve never had one of my SUN drives fail yet though.  They are built like tanks.  I’ve not looked too hard, but the community to provide new gears and belts is really in its infancy, so repair isn’t a good option right now. 

Spend the money on a drive in known good shape, if you don’t want to risk it. 

Also while I tend to reinstall via optical drive, many owners don’t want to bother and use a network based installation instead.  If you’re buying this optical drive just to reinstall, I’d advise you to first look into the VMs available for doing network installs. 

If you want the optical drive for other reasons, by all means go for it.


ok, big help thanks. I do have a SCSI cdrom from a Sun Ultra 30 I just found on my storage. I have no external bay for it as it’s an internal drive. Can I buy a converter cable for the big scsi ribbon cable to ultra wide and plug it in on the back of the Octane2?


RE: External SCSI CDROM drive - weblacky - 03-01-2021

Well technically yes, but by the time you’ve tracked down converters and stuff you likely would exceed the cost of an external CDROM enclosure and a SCSI cable + adapter on eBay.

You’re biggest issue will be a 68 to 50 pin external SCSI bus adapter. Assuming your CDROM is a 50 pin arrow SCSI, you can find a case for it and all that. Then adapt the external cables correctly.

In fact, being able to adapter the Octane external SCSI connector will likely come in handy in the future.

I guess it comes down to what you have available at what price.

To me, trying to use an internal to external ribbon is a big hassle and likely will affect performance and such.

I bought all my stuff many years ago, but I assumed if I’m going to do it, might as well try to get nice stuff that would last and also work on other SGIs. Nearly all my SGIs that can have internal optical drives do, but you may get several that cannot take them (Indy, Indigo, Octane, Octane2) so building a nice external drive helps you utilize other SGI machines you might obtain in the future.


RE: External SCSI CDROM drive - toncho11 - 08-30-2023

Hi,

I have an Aplle SCSI external CD-ROM. Would it work with my SGI Indy?
It does not seem to have the 512/1024 option.

[attachment=3307] [attachment=3306]

I just need to plug it at the back of the Indy?
I think there is a terminator on the internal SCSI cable.


RE: External SCSI CDROM drive - toncho11 - 08-31-2023

It is a an AplleCD 300e Plus.

http://www.bitsavers.org/pdf/apple/brochures/brochures/AppleCD300Series-BW2P.pdf

Are these designed to be used only by Apple or they can be used by other systems? This is the question.


RE: External SCSI CDROM drive - vishnu - 08-31-2023

(08-31-2023, 06:41 AM)toncho11 Wrote:  It is a an AplleCD 300e Plus.

http://www.bitsavers.org/pdf/apple/brochures/brochures/AppleCD300Series-BW2P.pdf

Are these designed to be used only by Apple or they can be used by other systems? This is the question.

I'm just guessing, but since Apple Computer SCSI devices use the infamous Macintosh-specific "transfer instruction block," those Apple devices probably won't work on SGI workstations, or, for that matter, anything other than a Macintosh. Just more of Apple's typical "walled garden" philosophy. Their attitude has always been, if it's not an Apple, just go away. That said though, if Microsoft had ever stopped porting Office to the Apple operating system, Apple would have gone out of business 25 years ago.


RE: External SCSI CDROM drive - robespierre - 08-31-2023

See http://giga.cps.unizar.es/~spd/pub/irix/cdrom-3rd-party.txt
and https://www.siliconbunny.com/mirrors/www-viz.tamu.edu/sgi-faq/faq/html/hardware/

External drive chassis normally are not terminated and require a terminator to be installed on the end of the chain (on one of the two outside SCSI connectors).


RE: External SCSI CDROM drive - weblacky - 08-31-2023

If the external enclosure supports termination you'll physically see either a screw driver turned selector or a small dip switch on the back of the drives enclosure that has the word termination or term on it. But that is extremely rare to have, if you don't see any marking for termination then yes you must provide your own external terminating plug on the unused SCSI connection in the rear.


RE: External SCSI CDROM drive - toncho11 - 09-01-2023

No success so far.
I do not have an external SCSI terminator.
So I should connect the SGI on the top or bottom socket at the back?
And use the other for the terminator.
I have selected SCSI ID from 3 to 1 at the back of the cd-rom using a screw driver. My hdd is SCSI 0.
Testing: I go to the command monitor and I enter "hinv" to see the list of scsi devices available.