Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!dciem!nrcaer!cognos!roberts From: roberts@cognos.uucp (Robert Stanley) Newsgroups: comp.arch Subject: Re: Wirth's "challenge" (was Re: RISC) Message-ID: <1883@cognos.UUCP> Date: Sat, 28-Nov-87 16:17:20 EST Article-I.D.: cognos.1883 Posted: Sat Nov 28 16:17:20 1987 Date-Received: Tue, 1-Dec-87 05:24:14 EST References: <902@mips.UUCP> <1775@cognos.UUCP> <5157@columbia.edu> Reply-To: roberts@cognos.UUCP (Robert Stanley) Organization: Cognos Inc., Ottawa, Canada Lines: 27 In article <5157@columbia.edu> dupuy@amsterdam.columbia.edu (Alexander Dupuy) writes: >Perhaps I'm misunderstanding you, but do you mean to say that the 801 had a >360/370 emulation mode? My understanding was that the PL/I (actually, PL.8) >compiler generated machine-independent intermediate code, which was transformed >by a later pass into 801 machine code. A back-end to convert the intermediate >code into 370 machine code existed ... I stand corrected - apologies to any misled by my earlier posting. Alexander Dupuy is quite right that intermediate code was output and then post-processed in various ways, including register allocation optimization (by graph colouring) and code generation for specific target machine. Amazing how quickly unused knowledge decays! >I have no idea if any of these things ever saw the light of day outside IBM Not in the form originally worked with in Building 801. However, the same RISC architecture became both the RT PC and the heart of a number of key pieces of the big mainframe systems. I have no idea what is currently used to program such equipment. -- R.A. Stanley Cognos Incorporated S-mail: P.O. Box 9707 Voice: (613) 738-1440 (Research: there are 2!) 3755 Riverside Drive FAX: (613) 738-0002 Compuserve: 76174,3024 Ottawa, Ontario uucp: decvax!utzoo!dciem!nrcaer!cognos!roberts CANADA K1G 3Z4