Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!cornell!uw-beaver!tikal!warren From: warren@tikal.Teltone.COM (Warren Seltzer) Newsgroups: comp.arch Subject: Re: ZISC computers Keywords: ZISC Message-ID: <1065@tikal.Teltone.COM> Date: 30 Nov 88 20:52:38 GMT References: <22115@sgi.SGI.COM> Reply-To: warren@tikal.UUCP (Warren Seltzer) Organization: Teltone Corp., Kirkland, WA Lines: 20 In the early seventies, the Burroughs 1700-series computers used this scheme for the *MICROCODE*. That is, the hardware was pretty much as you described, using registers instead of "memory", although there were other opcodes. The only code written in this machine language was microcode, diagnostic code, and research systems. As I remember, there was an "X" register, a "Y" register, and an "X+Y" register, from whence the sum was read, an "X * Y" register, an "X/Y" register, and so on. By the way, this was a very interesting machine in other ways as well. Warren -- (206) 827-9626 Warren Seltzer ...uw-beaver_____!tikal!warren Teltone Corporation .......fluke___/ P.O. Box 657 ...microsoft__/ Kirkland, WA 98033