The MIPS Magnum was a line of computer workstations designed by MIPS Computer Systems, Inc. and based on the MIPS series of RISC microprocessors. The first Magnum was released in March, 1990, and production of various models continued until 1993 when SGI bought MIPS Technologies. SGI cancelled the MIPS Magnum line to promote their own workstations including the entry-level SGI Indy. The early, R3000-based Magnum series ran only RISC/os, a variant of BSD Unix, but the subsequent Magnum workstations based on the Jazz architecture ran both RISC/os and Windows NT. In addition to these proprietary operating systems, both Linux and NetBSD have been ported to the Jazz-based MIPS Magnum machines.
Some models of MIPS Magnum were rebadged and sold by Groupe Bull and Olivetti. In addition, headless (i.e., without a framebuffer or video card) versions were marketed as servers under the name "MIPS Millennium".
The MIPS Magnum R4000 PC-50 includes a MIPS R4000PC processor with only 16 kB L1 cache (but no L2 cache), running at an external clock rate of 50 MHz (which was internally doubled in the microprocessor to 100 MHz).
The MIPS Magnum R4000 SC-50 is identical to the Magnum R4000PC, but includes one megabyte of secondary cache in addition to the primary cache.
The MIPS Magnum R4000 accepted eight 72-pin true-parity SIMMs, up to a maximum of 256 MB.
The MIPS Magnum 3000 used a MIPS R3000 processor and a custom, proprietary motherboard which incorporated the TURBOchannel bus (it is noted that DEC also manufactured the DECstation line of workstations running Ultrix, which also used MIPS processors and the TURBOchannel bus). The Magnum 3000 ran only RISC/os, which was MIPS Computer Systems, Inc.'s proprietary port of BSD Unix including some System V features.
The later Magnums, the MIPS Magnum R4000PC and MIPS Magnum R4000SC, also used a MIPS microprocessor — the MIPS R4000, a full 64-bit microprocessor available either in a low-cost version (the R4000PC) having 16 kB of L1 cache but no L2 cache, or a higher-performance version (the R4000SC) with 1 MB of secondary cache in addition to the 16 kB of primary cache.
As MIPS Computer Systems, Inc. had co-founded the Advanced Computing Environment consortium with Silicon Graphics, Microsoft, Motorola and others, the MIPS Magnum R4000 was intended to be MIPS' entry into the Windows NT workstation market. However, because MIPS Computer Systems, Inc.'s in-house effort to design a MIPS-based Windows NT system had met delays, MIPS Technologies abandoned its in-house efforts and instead licensed the Jazz design which Microsoft had developed in the early 1990s to facilitate the porting and development of Windows NT (it is to be noted that Windows NT was first developed on the MIPS architecture, and was only later ported to the Intel 386, DEC Alpha, and PowerPC architectures).
As such, the MIPS Magnum R4000 (and indeed all Jazz-based systems, such as the Acer PICA, NEC RISCstation, Olivetti M700, etc.) incorporated many features more common to Intel-based PC's than to the commercial UNIX workstations of the era — for example, the Magnum R4000 included an EISA bus, used IBM PS/2-compatible keyboards and mice, and used commodity chipset components whose control registers were mapped to memory locations set forth in the IBM AT standard.
The MIPS Magnum 3000, unlike the MIPS Magnum R4000, was not able to run Windows NT.
For the earlier, RISC/os-only MIPS Magnum 3000 machines, the correct port is NetBSD/mipsco. For the later, Windows NT-capable MIPS Magnum R4000, the correct port is NetBSD/arc.