From jbbrus at comcast.net Fri Sep 4 14:25:30 2009 From: jbbrus at comcast.net (Bernice Barnett) Date: Fri, 04 Sep 2009 14:25:30 -0600 Subject: [Abqlispscheme] I'm new to this list Message-ID: <4AA177BA.30202@comcast.net> My name is Jeff Barnett and I'm a life-long Lisp fan who has recently retired to Albuquerque. A mutual colleague introduced me to Jim Prewett who in turn introduced me to this list. As I'm sure you all know, Jim is very persuasive even using e-mail. The result is that I'm now scheduled to give the September 20 Sunday talk. The purpose of this post is 1) to tell you what the talk will be about and 2) to introduce my Lisping self. The Talk; My talk will be about CRISP (Crunching Lisp), a Lisp-like system that was designed and implemented circa 1971 to support development of speech understanding systems. (In other words, DARPA paid for this bit of Lisp lore through their Speech Understanding Research program.) CRISP provided many interesting program constructs including the following: a variety of "spaghetti" stacks, unusual control structures including coroutines in the context of the "spaghetti", lots of data structures including cons nodes that had one, ..., or eight cells, data types, slick naming mechanisms, and flexible memory management techniques. CRISP was designed to be used by medium to large groups of implementors and many of the mechanisms were there to keep them out of each other's hair (and namespaces). The talk will provide some historic context as well as a technical description of one of the many freaks in the Lisp Family tree. Me: In the 1960's DARPA, then called ARPA,sponsored the development of Lisp 2 on the IBM ANFS Q32 computer. Working on Lisp 2 was my introduction to Lisp. The project was joint between System Development Corp. (SDC), a think tank, and Information International Inc., Ed Fredkin's play pen. Since ARPA couldn't figure out how to manage a bunch of Lisp Kids, they cajoled Minsky at MIT and McCarthy at Stanford to be program God Fathers or Den Mothers as need be. The Q32 offered us approximately 48K 48-bit words and was a time-sharing machine with a typical load of about 15-20 users. I designed and implemented, with Bob Long, a Lisp 1.5 dialect in the late 1960's. That Lisp was used for more than a decade to support research at SDC and several other palaces. It ran on IBM 360 time sharing and restricted its address space to 2^16 32-bit words so a cons node fit in 4 bytes. That address space included a chunk of "small integers". The most interesting fact about this Lisp was that only two errors where found in the compiler/assembler during its entire life time; it was actually two manifestations of the same bug. A special implementation technique was invented that produced the robustness. Maybe we will talk about that one of these Sundays. For most of the 1970's I was involved with the DARPA SUR (Speech Understanding Research) Program. I managed to sneak in the development of two Lisp-like systems. One was CRISP, the subject of my talk (see above). CRISP ran under the IBM VM370 OS and we had around 4MB virtual memory-a vast amount for that time. Doug Pintar worked on CRISP with me. The other Lisp was an interpretive system that ran on a Raytheon mini-computer with 32k 16-bit words. We managed to implement an entire speech understanding system top-end (no signal processing) in that Lisp. I'm sure you have noted the severe resource constraints imposed on all of the systems I've mentioned so far. Well that was going to change in the future. In the late 1970's I went to USC/ISI for five years. The only Lisp available to me was Interlisp, a dialect and implementation I didn't like very much, so I did non-Lisp things for a while. The reason Interlisp drove me bats was unclear semantics, a major sin for a program language system. When I say unclear semantics, I have in mind a system where eval, the compiler, and the block compiler could compute different results for the same Lisp expression. In the mid 1980's I went to the Northrop Research and Technology Center (NRTC) and ran into the Symbolics Lisp Machine. Over the years I accumulated a bunch and used them for research in distributed problem solving among other things. With the advent of Common Lisp and the superb development environment provided by the Lisp machines, I realized that my days as a Lisp implementor were mostly passed. I stepped down to join the user class where I now hang out. These days, I run Allegro on my home PC. -- Jeff Barnett PS My wife looked at this e-mail a while ago and comment that it sounded like I was going to stand up and confess at an AA meeting. I said perfect.