[weblacky]

I'm pretty sure I mentioned this before but UNIX installed CDs are not CDs, it's impossible to mount them in MS Windows or MacOS so if you've gotten one to mount as a blank directory then you don't have a valid CD image or it's entirely corrupted.

All the old UNIX systems use a 512-byte block sector imaged optical install media which was equal to the sector size in hard drives at that time. They didn't want to put effort into extra firmware to read a normal CD ISO format so in essence the CDs provided are actually specially tailored hard drive images. In the case of SGI Irix they're EFS images with SGI hard drive disk labels but they've been aligned to fit on a CD. Optical discs still have a 2048-byte sectors, you just have to align the data so that if the software tries to read 512 blocks at a time, which is an even multiple of 2048, everything makes sense.

They do not carry CD file systems on them, you cannot mount them under anything other than their native operating system and often a Linux operating system. So the fact that you achieved the impossible means you don't have a valid image. You should've received an immediate error when trying to mount these images on any other machine because they're not ISOs. In real life they should really have the extension of .DD or.img. But we often labeled see the images as .ISO because else people complain and make a bunch of weird stink about it not being the correct extension. But in truth .iso is supposed to mean an CD image with an iso9660 file system present. That's not what these are...

So likely your images are corrupt or not real, download them again from a trusted source and treat them as drive images. You cannot crack them open, you cannot modify them, they are a black box that you either put their image on the Zulu SD or you burn them entirely to a CDR and trust that they're there. You will not be able to mount them unless you do it under Linux. Irix has NO LOOPBACK VFS support out of the box, there is a open source project for it though, so normally SGI Irix cannot mount drive images, that includes CD-ROM images. They have to be burnt onto media and the media physically inserted into a drive or drive emulator device like the Zulu.