Path: utzoo!utgpu!water!watmath!clyde!att!pacbell!rtech!hoptoad!gnu
From: gnu@hoptoad.uucp (John Gilmore)
Newsgroups: comp.arch
Subject: Some 1987 patents of interest
Message-ID: <5511@hoptoad.uucp>
Date: 2 Oct 88 07:58:12 GMT
Organization: Grasshopper Group in San Francisco
Lines: 55

(I would've crossposted to comp.parallel, but it's moderated, and crossposts
to moderated groups do not work.  Their tough luck, I guess.)

I was in the Sunnyvale Patent Library this week and looked up recent
patents issued in general purpose computers (class 364, subclass 200).
Unfortunately the library stopped sorting their patents by topic,
starting Jan 1988, so I have no data from after then.

Transputer		4,704,678	3 Nov 87	Inmos
	"Function Set for a Microcomputer", Michael D. May

Motorola DSP?		4,709,324	24 Nov 87	Motorola
	"Data Processor Control Unit Having an Interrupt Service using
	 Instruction Prefetch Redirection", Kevin L. Kloker

	This describes how to get low-latency interrupts in a pipelined
	machine, without losing cycles, by "instruction jamming" a couple
	of instructions into the prefetch stream when an interrupt occurs,
	without flushing the pipeline or changing the program counter.
	This makes things like CPU-mediated DMA work great, since an
	interrupt can take e.g. 1 cycle total.

Connection Machine	4,709,327	24 Nov 87	(individuals)
	"Parallel Processor / Memory Circuit", W. Daniel Hillis et al.

	This looks like the meat of the connection machine design.
	It probably has lots of stuff that up til the patent was considered
	proprietary.  Have at it!

MC68010 or 20		4,710,866	1 Dec 87	Motorola
	"Method and Apparatus for Validating Prefetched Instruction",
	John Zolnowski, Les Crudele, Michael E. Spak

	This is how they cope with page faults on prefetched instructions.
	The 680xx avoids a bus error on prefetch unless you actually use
	the instruction.  They also seem to avoid starting to execute an
	instruction until the whole thing has been prefetched.

Spectrum?		4,713,755	15 Dec 87	HP
	"Cache Memory Consistency Control with Explicit Software Instructions",
	W. S. Worley, Jr, Wm. Bryg, Allen Baum

XT/370			4,714,993	22 Dec 87	IBM
	"Apparatus and Method for Effecting Dynamic Address Translation
	 in a Microprocessor Implemented Data Processing System", David L.
	Livingston, Daniel J. Sucher, Brue M. Walk.

	This one describes the DAT implementation on the IBM XT/370,
	a "370 on an IBM PC card".  The XT/370 is implemented with a
	remicrocoded 68000, remicrocoded float chip, and a regular 68000
	to handle odd instructions and talking to the IBM PC.  This
	patent includes a COMPLETE SOURCE CODE listing for the prom
	code the support 68000 runs in assisting the emulation.
-- 
John Gilmore    {sun,pacbell,uunet,pyramid,amdahl}!hoptoad!gnu    gnu@toad.com