 Later models dropped the "Nimbus" name, although it was still used late enough to appear on some early (and still ISA-based) 486 models shipped in slightly taller (2 x 5.25" bay) cases.By this point, RM's computers were essentially ordinary IBM clones being sold specifically to the education market, with standard processors and buses, operating systems and software, as well as the normal ports (5-pin AT keyboard, 9-pin serial - including the mouse, 15-pin HD-sub VGA - although some 386 models used the less common 9-pin variant, etc), and the previous non-standard holdovers from the Z380 days long since abandoned.Despite moving to a standard IBM-compatible architecture from the X series onwards, RM somewhat unusually maintained backwards compatibility with software written for their original Nimbus model by way of a "PC186" program that could be launched from MS-DOS or via a Windows icon, and would reboot the machine in an operating mode compatible with it.