Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!decvax!genrad!mit-eddie!mit-vax!eagle!mhuxt!mhuxi!mhuxa!houxm!ihnp4!ixn5c!inuxc!pur-ee!uiucdcs!parsec!fuka From: fuka@parsec.UUCP Newsgroups: net.arch Subject: Re: uP architecture and the NOVA - (nf) Message-ID: <2402@uiucdcs.UUCP> Date: Tue, 19-Jul-83 00:15:54 EDT Article-I.D.: uiucdcs.2402 Posted: Tue Jul 19 00:15:54 1983 Date-Received: Wed, 13-Jul-83 08:25:33 EDT Lines: 23 #R:orca:-135800:parsec:32800002:000:1047 parsec!fuka Jul 11 16:12:00 1983 As a former programmer for Data General, I agree with most of what orca!andrew has to say about the Nova. It WAS a real pain to write software for, but the simple architecture made it cheap to produce out of TTL in those days, which made it cheap to sell. Just like the RISC, it was also fast (for the times) because it was such a simple instruction set to decode. If you think about the concepts in RISC, the Nova was actually a pretty far-sighted machine. That doesn't mean that I'd ever want to program one again, however. One minor point: The sixteenth bit of Nova addresses WAS used -- it was an indirect bit, which allowed for n-way indirection of memory references. Any indirect reference which found an indirect pointer which had this bit set would cause a second level of indirection. Some knock-off Nova manufacturers (AMPEX?) used this 'extra' bit to implement a doubling of the address space (but only through indirect addressing). Kent Fuka Parsec Scientific Computer Corp. {allegra|ihnp4|uiucdcs}!parsec!fuka