Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site redwood.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!ihnp4!houxm!whuxl!whuxlm!akgua!sdcsvax!sdcrdcf!hplabs!hpda!fortune!redwood!rpw3 From: rpw3@redwood.UUCP (Rob Warnock) Newsgroups: net.micro Subject: Re: Need a microprogramming consultant! Message-ID: <188@redwood.UUCP> Date: Mon, 11-Mar-85 06:25:06 EST Article-I.D.: redwood.188 Posted: Mon Mar 11 06:25:06 1985 Date-Received: Thu, 14-Mar-85 03:41:37 EST References: <504@ima.UUCP> <802@ucbtopaz.CC.Berkeley.ARPA> Organization: [Consultant], Foster City, CA Lines: 51 +--------------- | >Finally, it turns out that microprogramming is far from a new idea. It was | >originally proposed for an early British machine in 1952! | Not surpising. Most of the good "new" ideas in CS are rather old. Could you | supply a reference so I can read about it? +--------------- Try 1951. The paper (actually, speech) which is generally agreed to have started it all is: Wilkes, Maurice V., "The best way to design an automatic calculation machine", Manchester University Computer Inaugural Conference, (July 1951), pp. 16-18 All you want to know about early microprogramming (and more than you will EVER want to know about microprogramming in the IBM System/360 Model 40, the IBM 360/50, the RCA Spectra 70/45, and the Honeywell H4200) can be found in the text "Microprogramming: Principles and Practices" by Samir S. Husson (Prentice-Hall 1970) [which is where I found the above reference]. In a historical aside, Husson notes [p.25]: "It is believed that Wilkes introduced the term 'microprogramming' with its present meaning. However, the Lincoln Laboratory [at MIT] used it prior to 1950 to describe a system in which the individual bits in an instruction directly control gates in the processor." Those who remember the DEC PDP-8 (which owes much to the LINC processor) will recall this earlier meaning as applies to the PDP-8's OPR instructions and the IOT instruction. (You can build up a complex instruction by taking a basic instruction class and turning on or off individual action bits.) +--------------- | BTW, redwood!rpw3 posted a very detailed description of one form of | vertical microcode; as it appears in I/O devices, etc. He also mentions | bit-sliced machines (the AMD 2900), which make for fast design of fast | custom hardware... |