On Mon, 3 Jun 2013 11:02:10 -0500, Paul Gilmartin wrote:
On Mon, 3 Jun 2013 10:08:19 -0500, Tom Marchant wrote:
Why do you continue to refer to the area between 2GB and 4GB as
Within the bar? While it is true that some early presentations
depicted the bar as having a thickness of 2 GB,
There was a period during which virtual storage immediately above the
bar was not allocated. The rationale for not doing so was that
incorrect AMODE(31) address arithmetic could yield values in that
range.
I have no personal experience of the usefulness of this convention,
but several
It appears that IBM's intent in defining the bar was to make it equal to the
point where 31-bit addressing was no longer possible and any further
addressability required 32 or more bits.
Bill Fairchild
Franklin, TN
- Original Message -
From: Tom Marchant m42tom-ibmm...@yahoo.com
Yes and yes again.
I suspect that musical chairs was more important than denotation here:
Since 'line' was unavailable because already in use, 'bar' was
chosen--well chosen in my view--to disambiguate the demarcations of
AMODE(64) and AMODE(31) address spaces.
John Gilmore, Ashland, MA 01721 -
On Mon, 3 Jun 2013 08:46:24 -0400, John Gilmore wrote:
(Above-the-bar VSCR projects may be in the womb of time, but I judge
that their gestation period will be very long.)
A plausible judgment. But how about in between? Is VSCR below the bar
but above the line looming? I'd expect a motivator
On Mon, 3 Jun 2013 09:28:07 -0500, Paul Gilmartin wrote:
I understand that some of Java has migrated to within the bar
Why do you continue to refer to the area between 2GB and 4GB as
Within the bar? While it is true that some early presentations
depicted the bar as having a thickness of 2
On Mon, 3 Jun 2013 10:08:19 -0500, Tom Marchant wrote:
Why do you continue to refer to the area between 2GB and 4GB as
Within the bar? While it is true that some early presentations
depicted the bar as having a thickness of 2 GB, AFAIK, it was never
documented that way in any IBM manual.
DB2, IMS and CICS have already done considerable work moving stuff from
31- to 64-Bit, to name just three products.
Certainly in the case of DB2 it was vital. For CICS becoming more so.
Cheers, Martin
Martin Packer,
zChampion, Principal Systems Investigator,
Worldwide Banking Center of
On Mon, 2013-06-03 at 11:02 -0500, Paul Gilmartin wrote:
(Probably. If an interpreter
were make its smallest unit of addressable storage 8 bytes, it could still
address 32GiB with 32 bit addresses. I doubt that Java is implemented in
that fashion.)
The IBM Java implementation does precisely
