RISC/OS, IRIX

Hi everybody. I have a curiosity which I hope to satisfy with this question, and I hope that somebody knowledgeable with the history of Silicon Graphics or MIPS can help me out here. On working with the MIPS RISComputers that I have (one in full working order -- no drive light yet -- with three more and a drive light to follow), it occurs to me that the entire feel of the machine is astoundingly close to that of an SGI. To give some examples: The boot monitor is somewhat close -- using the same or similar commands, and the same or similar naming scheme for devices. The install script for RISC/OS and SGIs 'inst' are similar in ways. The FROM environment variable in the RISC/OS installer, and the 'from' command in inst, as an example. Directory structure is very close, and the configuration files seem to be in very similar locations -- by this, I mean more so than is normal between different unix systems. "The System is Coming Up" (Yes, this message is in the default install for both systems) These are all just superficial things, but they lead me to guess that there was a large amount of heritage from RISC/OS to modern IRIX. I assume this would have shown up around IRIX 2.0 (was 1.0 the IRIS 2000/3000 version?) Does anyone know whether I've come to the wrong conclusion? Does anyone know how deep the resemblance goes? I would be tempted to try a RISC/OS binary on an IRIX system at some point. In short, is anyone familiar enough with Silicon Graphics and/ or MIPS to explain this? Regards, Chris Christopher Smith, Perl Developer Amdocs - Champaign, IL /usr/bin/perl -e ' print((~"\x95\xc4\xe3"^"Just Another Perl Hacker.")."\x08!\n"); '