[Coco] How much memory

Willard Goosey goosey at virgo.sdc.org
Sun Nov 28 07:48:50 EST 2010

On Sun, Nov 28, 2010 at 12:52:08AM -0400, RJLCyberPunk wrote:
> I find it odd that OS9 has that limitation that all other current computer 
> operating systems do not have. why have the designers of OS9 built a 2MB 
> memory address limitation?

8K MMU blocks use 13 bits of address space/block.
8-bit block numbers would make a total of 21 bits = 2M address space.

That's my guess at 0530, anyway.  

IIRC Level II stores real addresses in 24-bits, so even with larger
block numbers (or larger blocks) it would max out at 16M anyway.

Also, eyebrow on "wha?" to OS-9/6x09 as a "current" operating
system... I'm sure the current Radisys OS-9 for, say, x86 or PowerPC
can handle 4G, and they might even have a 64-bit version in the

Willard Goosey  goosey at sdc.org
Socorro, New Mexico, USA
I search my heart and find Cimmeria, land of Darkness and the Night.
  -- R.E. Howard

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