Path: utzoo!attcan!uunet!know!zaphod.mps.ohio-state.edu!ub!acsu.buffalo.edu
From: axaris@acsu.buffalo.edu (vassilios e axaris)
Newsgroups: comp.arch
Subject: Re: Porting OSes
Summary: Hardware support for OSs
Keywords: KeyKOS Multics 68000 386
Message-ID: <41894@eerie.acsu.Buffalo.EDU>
Date: 21 Oct 90 20:48:51 GMT
References: <2059@aber-cs.UUCP>
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Organization: SUNY Buffalo
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In article <2059@aber-cs.UUCP> pcg@cs.aber.ac.uk (Piercarlo Grandi) writes:
> ************* vis (very interesting stuff) deleted ******************
>
>... . What about some research in minimalistic OS
>support architectural features? Or does the RISC concept stop at the ALU?
>-- 
Here at SUNY Buffalo such topics are covered (to my surprise at first)
in a course on comp. architecture by a professor who's regarded as an authority
in microprogrammable (completely horizontal microcode) systems. His name is
available upon request. His system, built from discrete SSI logic, occupying
a roomful, is still running without a hitch since early 70's! Part of the
course was topics as such. To name a few: large multiported register files
which support the concept of task and process workspaces, memory management
of paged systems supporting a large number of pages (1Meg :-)) using the LRU
algorithm implemented in hardware (was a great project to say the least!)
task management hardware which supported multitasking at the microprogram
level, and provided security at the same level. Undoubtedly complex systems
but offering a high level of functionality, for time-sharing as well as real
time systems. Needless to say that he was against the RISC philosophy for
the simple reason, that all these complex functions could not be supported
efficiently due to the approach's simplicity.
Anyone care to start a discussion on these topics? :-)

Vassilios E. Axaris
Dept. of Electrical and Computer Engineering,
SUNY at Buffalo.