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Cyhist Apr 09 1997 A
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Date: Wed, 9 Apr 1997 08:35:55 -0700
Reply-To: "CYHIST Community Memory: Discussion list on the History of
Cyberspace" <CYHIST@MAELSTROM.STJOHNS.EDU> Sender: "CYHIST Community Memory: Discussion list on the History of
Cyberspace" <CYHIST@MAELSTROM.STJOHNS.EDU> From: John Ahlstrom <jahlstro@CISCO.COM>
Subject: Re: 1401 architecture
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Community Memory: Discussion List on the History of Cyberspace ______________________________________________________________________
Laurence I Press wrote:
>I believe it was 6 bits plus the "word mark." The word mark was a seventh bit used to delimit data fields and instructions. There were also instructions to set, clear, and test the bit mark, and memory- starved programmers could use them to pack in extra data as well.
I believe there was an 8th bit -- the record mark and that the word mark was used to end fields in a record and the record mark to end the record.
I believe that "byte" was used in the Bucholz book "Project Stretch".
Certainly everyone at IBM was familiar with the 1401 when the 360 was architected, but I don't remember any non-trivial similarities and do remember significan differences; for example, the 360 way of determining the length of variable length operands was completely different from that of the 1401.
John Ahlstrom
jahlstrom@cisco.com
Amateurs discuss product strategy;
professionals discuss account control.
______________________________________________________________________
Reply-To: "CYHIST Community Memory: Discussion list on the History of
Cyberspace" <CYHIST@MAELSTROM.STJOHNS.EDU> Sender: "CYHIST Community Memory: Discussion list on the History of
Cyberspace" <CYHIST@MAELSTROM.STJOHNS.EDU> From: John Ahlstrom <jahlstro@CISCO.COM>
Subject: Re: 1401 architecture
______________________________________________________________________
Community Memory: Discussion List on the History of Cyberspace ______________________________________________________________________
Laurence I Press wrote:
>I believe it was 6 bits plus the "word mark." The word mark was a seventh bit used to delimit data fields and instructions. There were also instructions to set, clear, and test the bit mark, and memory- starved programmers could use them to pack in extra data as well.
I believe there was an 8th bit -- the record mark and that the word mark was used to end fields in a record and the record mark to end the record.
I believe that "byte" was used in the Bucholz book "Project Stretch".
Certainly everyone at IBM was familiar with the 1401 when the 360 was architected, but I don't remember any non-trivial similarities and do remember significan differences; for example, the 360 way of determining the length of variable length operands was completely different from that of the 1401.
John Ahlstrom
jahlstrom@cisco.com
Amateurs discuss product strategy;
professionals discuss account control.
______________________________________________________________________
