SGI IRIS

With the IRIS 2000 series (released in 1985) came SGCS's first internally-designed processor, with a Motorola 68010 running at 10 MHz.

Like the IRIS 1000 series which preceded it, the 4D/60 did not use an internally designed processor board, instead using a generic MIPS systems board (likewise, the earliest versions of the new operating system for the MIPS-based workstations, dubbed '4D1', was largely derived from MIPS' own RISC/OS).

[7] The 4D/35 would later be cost-reduced into the IRIS Indigo, released in 1991, which was so architecturally similar to the 4D/35 that it shared the same Internal Processor ID (IP12) in software.

[8] Beginning in late 1992 with the release of the Indigo² and Challenge, the 'IRIS' prefix would be dropped from the names of all future systems, as well as the '4D/' model numbers.

However, all future MIPS-based systems released by Silicon Graphics would still use 'IRIS' as the default hostname, ending with the Tezro in 2003.

A unifying feature across all IRISes – 68K, Professional, Personal, PowerSeries, Indigo, Crimson, and Onyx – is a proprietary serial-based keyboard/mouse protocol.