For anyone else who was captivated by: "Denis came up with a nice little language that had a bit of an APL feeling for humans to program this system in" - here is a link to the 184 page paper describing "DCPL": http://content.lib.utah.edu/cdm4/item_viewer.php?CISOROOT=/ir-main&CISOPTR=60083 -shaun
On Fri, Sep 2, 2011 at 9:23 AM, Alan Kay <alan.n...@yahoo.com> wrote: > Hi Jecel > I think both these sections were reactions to some of the current hardware, > and hardware problems of the time. > > I remember the second one better than the first. In those days cutting dies > out of the wafters often damaged them, and the general yield was not great > even before cutting the die out. This idea was to lay down regions of memory > on the wafer, run bus metalization over them, test them, and zap a few bits > if they didn't work. The key here was that the working ones would each have > a register that had its "name" (actually its base address and range) and all > could look at the bus to see if their address came up. If it did, it would > seize the bus and do what ever. So this was a kind of distributed small > pages and MMUs scheme. And the yield would be much higher because the wafers > remained intact. I don't think any of these tradeoffs obtain today, though > one could imagine other kinds of schemes for distributed memory and memory > management that would be more sensible than current schemes. > The first one I really don't remember. But it probably was partially the > result of the head per track small disk that the FLEX machine used -- and > probably was influenced by Paul Rovner's scheme at Lincoln Labs for doing > Jerry Feldman's software "associative triples memory". > > I think this was not about Denis Seror's later and really interesting thesis > (under Barton) to make a "lambda calculus machine" -- really a "combinator > machine" (to replace variables by paths) and to have the computation on the > disk and just pull in and reduce as possible as the disk zoomed by. All was > done in parallel and eventually all would be reduced. Denis came up with a > nice little language that had a bit of an APL feeling for humans to program > this system in. He (and his wife) wound up making an animated movie to show > people who didn't know about lambda expressions and combinators (which was > pretty much everyone in CS in those days) what they were and how they > reduced. > There's no question that Bob Taylor was the prime key for PARC (and he also > had paid for most of our PhDs in the 60s when he was an ARPA funder). > Cheers, > Alan > > ________________________________ > From: Jecel Assumpcao Jr. <je...@merlintec.com> > To: Alan Kay <alan.n...@yahoo.com> > Cc: Fundamentals of New Computing <fonc@vpri.org> > Sent: Thursday, September 1, 2011 3:17 PM > Subject: a little more FLEXibility (was: [fonc] Re: Ceres and Oberon) > > Alan, > >> The Flex Machine was "the omelet you have to throw away to clean the pan", >> so I haven't put any effort into saving that history. > > Fair enough! Having the table of contents but not the text made me think > that perhaps the section B.6.b.ii The Disk as a Serial "Associative > Memory" and B.6.c. An Associativeley Mapped LSI Memory might be > interesting in light of Ian's latest paper. Or the first part might be > more related to OOZE instead. > >> But there were "4 or 5" pretty good things and "4 or 5" really bad things >> that >> helped the Alto-Smalltalk effort a few years later. > > Was being able to input drawings one of the good things? There was one > Lisp GUI that put a lot of effort into allowing you to input objects > instead of just text. It did that by outputting text but keeping track > of where it came from. So if you pointed to the text generated by > listing the contents of a disk directory while there was some program > waiting for input, that program would read the actual entry object. > > It is frustrating for me that while the Squeak VM could easily handle an > expression like > > myView add: <yellowEllipseMorph> copy. > > I have no way of typing that. I can't use any object as a literal nor as > input. In Etoys I can get close enough by getting a tile representing > the yellowEllpiseMorph from its halo and use that in expressions. In > Self I could add a constant slot with some easy to type value, like 0, > and then drag the arrow from that slot to point to the object I really > wanted. It was a bit indirect but it worked and I used this a lot. The > nice thing about having something like this is that you never need > global variable again. > >> I'd say that the huge factors after having tried to do one of these were >> two >> geniuses: Chuck Thacker (who was an infinitely better hardware designer >> and >> builder than I was), and Dan Ingalls (who was infinitely better at most >> phases >> of software design and implementation than I was). > > True. You were lucky to have them, though perhaps we might say Bob > Taylor had built that luck into PARC. > > -- Jecel > > > > > _______________________________________________ > fonc mailing list > fonc@vpri.org > http://vpri.org/mailman/listinfo/fonc > > _______________________________________________ fonc mailing list fonc@vpri.org http://vpri.org/mailman/listinfo/fonc
