Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83 SMI; site sun.uucp Path: utzoo!watmath!clyde!floyd!harpo!decvax!decwrl!sun!wmb From: wmb@sun.uucp (Mitch Bradley) Newsgroups: net.arch Subject: Re: looking for stack machines Message-ID: <553@sun.uucp> Date: Tue, 6-Mar-84 22:27:29 EST Article-I.D.: sun.553 Posted: Tue Mar 6 22:27:29 1984 Date-Received: Thu, 8-Mar-84 07:41:11 EST References: <3523@tekecs.UUCP> <27900008@ucbesvax.UUCP> Organization: Sun Microsystems, Inc. Lines: 25 Charles Moore, the inventor of FORTH, is building a FORTH machine. He described it a the FORTH Modification Laboratory conference at Asilomar last November. Unfortunately, his presentation was verbal, and there was not a written version in the conference proceedings. Basically his is an ECL processor with 2 hardware stacks, one for passing arguments and the other for holding return addresses for subroutines (FORTH programmers will recognize this architecture as closely resembling the FORTH virtual machine). Both the top-of-stack and the second-on-stack are instantly accessible (i.e. in one microcycle) for both stacks. The machine is microcoded in such a way that FORTH code may be easily compiled into a near-optimal set of microinstructions. The mapping is interesting. In one particular case, a sequence of 5 FORTH operations compiles into a single microinstruction. In November, he showed the film for his PC board, which he had just gotten back from the photo house. He expects the first rev of the computer to run with a 16 nsec. microcycle time. He did all of the design work on a home-brew CAD system (written in FORTH of course) which was pretty impressive, but not general purpose. It runs on an 11/23, and does layout, simulation, timing analysis, etc. Mitch Bradley Sun Microsystems, Inc.