On Tue, Dec 5, 2017 at 7:38 AM, Tom Marchant < [email protected]> wrote:
> When the System/360 was designed, nearly every new computer was different > and incompatible with previous ones. Computer architectures came and went, > few of them lasting very long. It is remarkable that the basic > architecture of the > System/360 has lasted for well over 5 decades while continuing to evolve. > > Amdahl, Blaauw, and Brooks, the principle designers of the System/360, > wrote > a paper in the IBM Journal of Research and Development in 1964, titled > "Architecture of the IBM System/360." In it they describe the trade-offs > that > they considered and the reasons for the decisions that they made. I think > of > it as a 15 page precursor of the Principles of Operation. > > For anyone interested in the reasons why S/360 was designed the way it was, > I highly recommend it. Here are a couple of places where it can be found. > > http://www.ece.ucdavis.edu/~vojin/CLASSES/EEC272/S2005/ > Papers/IBM360-Amdahl_april64.pdf > > http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1. > 72.7974&rep=rep1&type=pdf Really nice. I haven't read it yet, but I hope it does answer some of my "Why?" questions. > > > -- > Tom Marchant > > On Mon, 4 Dec 2017 23:17:40 +0000, Swarbrick, Frank wrote: > > >I think someone else said it was choosing EBCDIC over ASCII. Personally I > think that one's worth, because apparently it will never be "fixed". > > > >-----Original Message----- > >From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@ > LISTSERV.UGA.EDU] On Behalf Of Charles Mills > >Sent: Monday, December 4, 2017 3:55 PM > >To: [email protected] > >Subject: [EXTERNAL] Re: Access registers > > > >I believe someone (Harlan Mills? Fred Brooks?) said that he felt the only > (or most significant?) *error* in the System 360 design was the 24- >rather > than 31- or 32-bit addressing. > -- I have a theory that it's impossible to prove anything, but I can't prove it. Maranatha! <>< John McKown
