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From: hank@spook.UUCP (Hank Cohen)
Newsgroups: comp.arch
Subject: Re: Was the 360 badly-designed?  (was Re: Compatibility with EBCDIC)
Message-ID: <114@spook.UUCP>
Date: Wed, 26-Aug-87 13:21:34 EDT
Article-I.D.: spook.114
Posted: Wed Aug 26 13:21:34 1987
Date-Received: Sat, 29-Aug-87 08:48:30 EDT
References: <1486@cullvax.UUCP>
Reply-To: hank@masscomp.UUCP (Hank Cohen)
Organization: MASSCOMP -- Bethesda Md.
Lines: 37
Summary: The 370 really is a system architecture

One thing that people seem to be missing in this discussion of the 370
architecture is that the 370 POO specifies much more than the user
instruction set.  The architecture specification is for a complete
system of which the instruction set is only one component.  One of the 
best features of the 370 is its I/O architecture.  (I expect this 
might be somewhat controversial.)  It took SCSI to bring simplicity
and consistency to small computer I/O systems.  System 360 has had it
for 20 years.
	 Another provision of the system architecture that is  overlooked 
in all micro systems that I have seen is error logging and diagnosis.
In this age of super fast micro processors and very large scale
integration none of the new RISC chips have thought it prudent to
provide architectural support for fault detection and diagnosis.  At
least if such support has been provided it has not been made evident
from the discussion in this group.  I think that there are mistaken
priorities at work when speed of computation is persued to the
detriment of correctness.
Again the 360 architecture was ahead of the pack by specifying 
a minimum error logging capability for all members of the family.
Most current implementations of the architecture provide much more
error logging and diagnostic capability than the minimum.
     In the UNIX community there is a general tendency to bash IBM for
 the shortcomings of the 370.  I will be the first to grant that
 MVS/TSO and all of the standard IBM software products give the term
 "User Hostile" new meaning.  But before condeming the system
 architecture for it's faults we should learn from the many things
 that the designers of the 360/370 did right.

 History is two steps foreward and one step back.

 I suppose that I should add that these views are my own and not
 necessarily those of anyone else associated with MASSCOMP.

 Hank Cohen
 MASSCOMP 
 7315 Wisconsin Ave. Suite 1245W
 Bethesda Md. 20814 (301)657-9855