Talk:Data General Eclipse MV/8000
|WikiProject Computing / Hardware||(Rated Stub-class)|
"The Eclipse MV/8000 was the first in a family of 32-bit minicomputers produced by Data General during the 1980s." I doubt this is true. The MV/7800 is 32 bit. Was is before the MV/8000?
Clarification note: The MV/8000 was the first machine in the 32 bit MV series (as evidenced in Soul of a New Machine where the original development of wire-wrapped prototypes of the ALU, ATU (etc) cards is described). The MV/7800 was developed later as a single-chip implementation of the MV CPU architecture, and was slower than the MV/8000. The MV/7800XP was a subsequent evolution of the MV/7800, and was faster than the MV/8000.
"The Eclipse MV was a 32-bit CISC architecture with a 4GB address space." Not true. The MV/7800 XP is preconfigured with 2 or 4 MiB. Expandable to 14 MiB.
Clarification note: It is correct that the 32bit MV architecture supported a 4GB address space. This was a virtual address space, in which unused pages of memory were swapped from physical memory out to disk, and swapped back in again when needed. Physical memory size could therefore be much smaller than 4GB. It was the job of the ATU (Address Translation Unit) to perform fast mapping between the physical and virtual address spaces.
"The outermost ring, ring-7, was the least privileged. The inner-most ring, ring-0 was the most privileged." Not true. I will read the manual tomorrow and update this comment - paraphrased. — Preceding unsigned comment added by 188.8.131.52 (talk) 18:57, 4 March 2014 (UTC)
Clarification note: It is correct that Ring 0 was the most privileged, and Ring 7 the least. Each virtual memory page existed in the context of a specific ring. Later operating system implementations including OS/2 followed the ring based memory protection scheme (although with a lower number of rings).