Interval Smalltalk redux (was "SqueakOS")

Alan Kay squeak-dev at lists.squeakfoundation.org
Fri Oct 4 02:16:52 UTC 2002


Thanks Craig --

I really feel there will be an opportunity not too far in the future 
when a lot of this great technology will make a big difference, and 
will be very worthwhile to revisit....

Cheers,

Alan

------

At 4:50 PM -0700 10/3/02, Craig Latta wrote:
>	Daniel writes:
>
>>  And of course, this wonderful code is buried somewhere to never be
>>  used again.
>
>short answer: It's not as bad as that.
>
>long answer:
>
>         I'm sure the following is in the Google archives somewhere, but
>I'm too lazy to look it up... anyone please feel free to correct me.
>
>         I was on the Interval Smalltalk team. Our system was part of a
>local media network system (homes, cars, etc.) which used a novel
>networking protocol ("MediaWire") that was cheap (ran over phone wire),
>synchronous, could support variable bitrates, and was, for the time,
>fast (100Mb). We worked on the "MediaPad", a sort of glorified remote
>control, a letter-sized touchscreen device with which you could control
>all the connected devices, make new composite devices, etc. It was
>similar in appearance to the failed crop of "web pads" which kept
>appearing later :). Tim and I showed off a couple of them at OOPSLA '99.
>I designed the device driver framework (a precursor to Flow).
>
>         At the end of the project, we got permission to release all the
>non-MediaWire-specific software (pretty much the whole virtual machine,
>and most of the object memory). The catch is that only two of us had
>working MediaPad-building environments at the end (the end came
>suddenly). A different two of us (Tim and myself) had working MediaPads.
>Unfortunately, we've never been motivated enough collectively to get all
>the bits and hardware back together. Doing so would be some non-trivial
>amount of work, and we've all been busy with other things since. I
>actually have been releasing parts of the object memory over time,
>starting with the exception-handling framework I wrote (when Squeak
>didn't have one), then moving on to the device stuff. It's generally
>slow going though, because writing and performing music always gets more
>of my time.
>
>         I expect the complete system would take a non-trivial amount of
>rework to retarget to different hardware. The MediaPad was always a
>home-grown prototype (based on the StrongARM 1100, and custom ASICs, at
>no small cost). The native code generator wouldn't be immediately useful
>to all Squeakers, for example. Some of the ARM development tools we used
>are not open-source. Another problem not to be underestimated is that
>both Tim and I have so far been too paranoid to attempt rewriting either
>of the MediaPad ROMs, for fear of the population of known demo-able
>MediaPads dropping by half. :)  Also, the system got basic testing, but
>the project died before we could really pound it in actual homes.
>
>         Anyway, the software is not closed as far as I know, but it's
>not in a state where it can meaningfully be distributed as a single
>coherent system. I think it's fair to say that most of us wouldn't feel
>right distributing something that people can't just fire up and use
>(leftover pride I suppose :). That mostly explains why the occasional
>"why doesn't the Interval Smalltalk system get released?" query is met
>with relative silence.
>
>         I've always wanted to eventually get the whole thing released,
>though, and I plan to keep at it. I think a proper revival of the
>project would be a lot of fun and still very useful, too, but we'd have
>to solve the hardware environment problem first. I'm game. :)
>
>	John writes:
>
>>  The Interval project was a special case. They were building their
>>  own custom hardware, so they HAD to write their own device drivers...
>
>	Well, that was just the MediaPad and assorted networking glue
>(standalone clocks, hubs, etc.); the situation was a little more...
>interesting. Part of the plan was to collaborate with the major consumer
>electronics firms to establish MediaWire as a common interconnection
>technology (e.g., you'd find MediaWire ports on next-generation TVs, CD
>players, etc.). We were going for all the traditional closed-spec
>devices in addition to our own stuff, by being part of the specs. It was
>Big.:)  The Japanese financial crisis in 1998 took most of the wind out
>of those sails (the biggest potential collaborators were deeply
>affected). I tend to agree with Tim that Mr. Bill finished it off.
>
>>  ...and they had a large team of both hardware and software engineers.
>
>	It wasn't that large, really. The comparison we liked to bat around was
>the fifteen of us versus the thousand people developing WinCE. :)
>
>	Tim writes:
>
>>  I'm pretty much convinced [implementing everything, including device
>>  drivers, in Smalltalk] isn't really worth it. At least, not unless
>>  one can fairly seriously rejig things to provide useful OS type
>>  facilities like protection of one application's memory from another,
>>  all that stuff.
>
>	Indeed... and I thought we were well on our way. :)  I thought having
>everything written in Squeak was fantastic. It made debugging things
>easier, and it was much simpler to explain the overall system
>architecture to newcomers. It afforded a great deal of useful technical
>control. And it was just more fun, which does have value.
>
>	At the same time, I'm all for creating the illusion of object memory
>anywhere it's useful, including OSKit and the "commodity" OS platforms.
>The trick is where to stop... in Interval's case, there were very good
>technical and business reasons for "going deep". Most of the time, as a
>single individual with a limited lifespan, I'm content to get on with
>higher priorities as long as the supporting stuff isn't too distracting.
>
>>  I agree with Dan's old aphorism about the OS but I think a better
>>  interpretation of it is that nothing in the OS should be unreachable
>>  from your language - not that there shouldn't be the OS there at all.
>
>	To a large degree I view The Aphorism as a statement of that time, when
>the technology wasn't as pervasive and things were more open to change.
>And somewhere there should be a footnote: "Things get weird when
>billionaires are nearby."  :)
>
>
>-C
>
>--
>Craig Latta
>improvisational musical informaticist
>craig at netjam.org
>www.netjam.org/resume
>Smalltalkers do: [:it | All with: Class, (And love: it)]


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