In [EMAIL PROTECTED], on 10/21/2008
at 05:30 PM, Scott Ford [EMAIL PROTECTED] said:
Starting writing Assembler on a 360/20,, man 704 days...
I won't try to justify the 704, but one (IBMAP) of the assemblers on,
e.g., the 709, 7090, had a facility (QUAL) that HLA still doesn't have.
And the
Robert A. Rosenberg wrote:
There was also the secondary use of the high bit to signal AM24 vs
AM31 in addresses used for branching to/from subroutines. This
required replacing BALR with BASR and BR with BSM to do the AM Mode
Switch.
And, the low-order bit of the address now indicates
The following message is a courtesy copy of an article
that has been posted to bit.listserv.ibm-main as well.
[EMAIL PROTECTED] (Robert A. Rosenberg) writes:
There was also the secondary use of the high bit to signal AM24 vs
AM31 in addresses used for branching to/from subroutines. This
On Mon, 20 Oct 2008 22:00:00 -0500, Paul Gilmartin
[EMAIL PROTECTED] wrote:
...
I thought 31-bit was for compatibility with existing exploitation
of the sign bit; ...
Nope, it was the use of a X'80' in the high-order byte of a fullword to
terminate a variable-length parameter list (of
Right, but I think it's fairly clear that they
were both talking about the same thing.
Date: Tue, 21 Oct 2008 14:16:43 -0500
From: [EMAIL PROTECTED]
Subject: Re: Addressing Scheme with 64 vs 63 bits
To: IBM-MAIN@BAMA.UA.EDU
On Mon, 20 Oct 2008 22:00:00 -0500, Paul Gilmartin
[EMAIL
On Tue, 21 Oct 2008 15:38:56 -0400, J R wrote:
Right, but I think it's fairly clear that they
were both talking about the same thing.
... and I chose the term simply because I can never
remember which systems number bits left-to-right, and
which right to left, or start with 0, or start with
: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf
Of Paul Gilmartin
Sent: Tuesday, October 21, 2008 4:25 PM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: Addressing Scheme with 64 vs 63 bits
On Tue, 21 Oct 2008 15:38:56 -0400, J R wrote:
Right, but I think it's fairly clear
Paul Gilmartin wrote:
... and I chose the term simply because I can never
remember which systems number bits left-to-right, and
which right to left, or start with 0, or start with 1.
And I think the IBM 704 didn't even number the sign
bit -- it was simply S, and didn't (sometimes)
participate in
PROTECTED] On Behalf
Of Gerhard Postpischil
Sent: Tuesday, October 21, 2008 5:16 PM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: Addressing Scheme with 64 vs 63 bits
Paul Gilmartin wrote:
... and I chose the term simply because I can never
remember which systems number bits left-to-right, and
which
And why was it expected to be 63 bit ? Was there an expectation that one
bit will be used to distinguish a 63 bit address from 31 / 24 bit addresses ?
Mohammad
On Sun, 19 Oct 2008 23:33:22 -0700, Edward Jaffe
[EMAIL PROTECTED] wrote:
It's analogous to why IBM implemented 64-bit addressing
Mohammad Khan wrote:
And why was it expected to be 63 bit ? Was there an expectation that one
bit will be used to distinguish a 63 bit address from 31 / 24 bit addresses ?
During the early discussions, many people expected ESAME to implement
63-bit addressing for reasons similar to why
On Mon, 20 Oct 2008 09:57:12 -0700, Edward Jaffe wrote:
Mohammad Khan wrote:
And why was it expected to be 63 bit ? Was there an expectation that one
bit will be used to distinguish a 63 bit address from 31 / 24 bit addresses ?
No, because there was no prior convention of using a doubleword
to
On Mon, 20 Oct 2008 15:00:48 -0500, Paul Gilmartin
[EMAIL PROTECTED] wrote:
I thought 31-bit was for compatibility with existing exploitation
of the sign bit; but there was no legacy convention of using
the sign bit of shorter addresses stored in a doubleword to
preserve compatibility with.
: Addressing Scheme with 64 vs 63 bits
To: IBM-MAIN@BAMA.UA.EDU
On Mon, 20 Oct 2008 15:00:48 -0500, Paul Gilmartin
[EMAIL PROTECTED] wrote:
I thought 31-bit was for compatibility with existing exploitation
of the sign bit; but there was no legacy convention of using
the sign bit of shorter
On Mon, 20 Oct 2008 20:31:08 -0500, W. Kevin Kelley wrote:
On Mon, 20 Oct 2008 15:00:48 -0500, Paul Gilmartin
[EMAIL PROTECTED] wrote:
I thought 31-bit was for compatibility with existing exploitation
of the sign bit; ...
Nope, it was the use of a X'80' in the high-order byte of a fullword to
At 22:00 -0500 on 10/20/2008, Paul Gilmartin wrote about Re:
Addressing Scheme with 64 vs 63 bits:
On Mon, 20 Oct 2008 20:31:08 -0500, W. Kevin Kelley wrote:
On Mon, 20 Oct 2008 15:00:48 -0500, Paul Gilmartin
[EMAIL PROTECTED] wrote:
I thought 31-bit was for compatibility with existing
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