Re: Address bits again, Article on new mainframe use

According to MitchAlsup1 <mitchalsup@aol.com>:

The 386 had 32 bit segments which should have made segmented code
practical and efficient ...

The other was that they mapped all the segments into a 32 bit linear address space, and
paged the linear address space.  That meant that the total size of all active segments
had to fit into 4GB, at which point people said fine, whatever, set all the segment
registers to map a single 4GB segment onto the linear address space and used it as
a flat address machine.

>
Intel's only other choice was to use more than 32-bits as the segment
base address and they had run out of bits.

The other choice would have been a page table per segment, like Multics did.

That would have been more hardware for the pager, no idea whether it
would have been practical to build with the chip process available at the time.


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