The RM 200 is a MIPS based workstation series originally developed by Pyramid which got bought out by Siemens-Nixdorf. The RM 200 was being shipped with SINIX or BS2000/MIPS as the OS in big endian mode and for Windows NT in little endian mode.
With a special floppy disk containing firmware it is possibly to reconfigure RM 200 systems from little- to big endian and vice versa. Unfortunately the firmware is copyrighted and Linux/MIPS project neither has a copy of the big endian firmware disk nor the permission to distribute the firmware or any other source.
The RM 200 systems use ARC firmware in the little-endian mode.
The RM 200 systems use SNI Monitor in the big-endian mode.
No Linux distribution supports the RM 200 out of the box so any installation will require some Linux skills and an additional Linux system to boot the RM 200 from via network. Linux support for the RM200 is available since kernel version 2.1 (requires out of tree patches). Due to a hardware problem for which for a long time no workaround was known Linux 2.2 and 2.3 were unsupported on RM 200; late 2.5 versions fixes these issues. Latest successfully tested version is 2.6.10-rc3 and is considered stable.
Current status about the big endian support could be found here User:Tsbogend
There are at least 5 different versions of the RM 200 as indicated by a letter trailing the version number. The C version can be distinguished from older versions by having both EISA and PCI slots on a riser board that sits in the middle of the main board.
RM-200 is based on the A20R Pyramid architecture and very similar to the early RM-400 (without C or E suffix).