squeak on iLiad

>
> On 13-Oct-07, at 12:17 PM, Brad Fuller wrote:
>
>
>> can you tell us more about the Active Book you worked on 20 years ago?
>
> Oh my, most of the old-timers will know that I can go on about that
> for hours. Days!
>
> OK, try to keep it short tim -
>
> The Active Book was a neat idea (especially for 1988) to make a
> portable tablet like computer with a digitiser screen, lots of power
> and a decent user interface. In short, someone's idea of a dynabook.
> The UI concept was to emulate a book but extend the idiom in the ways
> that a dynamic system could allow. So, documents were to be on pages
> and flipping pages would move between docs and the systems running
> them. No real use for overlapping windows - they were a foreign
> concept to almost everyone outside a limited world back then. The idea
> of the book was really to provide a concept of a contained world with
> logical separation between parts; just like a book has everything
> between the front and back pages and separated into chapters etc. I
> suspect it wouldn't really seem so neat these days now that we're all
> so used to Windows and OSX etc.
>
> The hardware was about the size of a MacBook, a bit thicker since the
> practical batteries back then were rather large cylinders. It had a
> whopping great big screen of amazing 640 by 400 resolution, monchrome.
> There was  stylus based digitiser and a panel to one side (can't
> remember which) that was a finger activated digitiser, intended for
> 'other input'. I'm pretty sure it was Bill Buxton that convinced them
> of the usefulness of that idea.
>
> It had an ARM2aS cpu running at 4MHz (maybe 6?) and 1Mb ram for
> everything - screen memory, fax filing, OS, the lot. Oh and 1Mb ROM
> too. The ARM was custom designed in-house to extend the basic ARM
> architecture to allow implementation as a static logic part, meaning
> we could simply turn off the power and it would sit there until it was
> time to go again. For cpu history buffs, the ARM 2 series had no
> cache; none at all. Not even an instruction prefetch queue. It was the
> first broadly used RISC machine (yes I know about the Sparc) and
> required  whopping great 25,000 transistors worth of silicon. In fact
> we used to joke about '25,000 transistors and no Gates'. Even the
> latest ARM cores need barely 50,00 transistors I'm told. Despite the
> above, the Acorn desktop machines that were on sale back then and
> using the base ARM2 cpus were several times faster than the hottest
> intel based boxes of the time.
>
> The OS was a version of Helios (eek, I still have a copy of the Helios
> manual in my bookshelf!) which I think started out life as TripOS at
> Cambridge (the real university, not the US) as a multi-processor
> system using messaging, or something like that. It was wrapped in a
> unix-like layer to please the unix-weenies.
>
> On top of that was Smalltalk. The VM was derived from EliotMiranda's
> famous BrouHaHa with a lot of extension for multiple non-contiguous
> memory spaces, ROMability, survivability, extra prims, blah blah blah.
> One of the acceptance tests for releases was to use up enough memory
> to get down to a couple of hundred bytes left and see if it could open
> a notifier, let the user kill the process and recover to full
> usefulness. Try doing that in most modern systems.. The image was
> licensed from ParcPlace, probably through Smalltalk Express though who
> knows what went on in that particular liaison? A small number of smart
> people worked on the image to make it do what was needed and some
> really interesting stuff was written. What really seems amazing to me
> now is that even with such a puny cpu and tiny amount of memory the UI
> was very snappy. You could for example draw/scribble on the screen and
> produce a drawing (not a bitmp type scribble) that kept up with the
> scribble. Then choose the eraser and scribble with that to erase
> *sections* of the lines. I bet they were even the correct sections!
> Remember, this is a cpu with less power than the one in your keyboard,
> probably with less memory than in your keyboard, running a fairly
> simple interpreted Smalltalk VM. You can see why I've always laughed
> hysterically at people that tried to claim Smalltalk is slow.
>
> Anyway, we worked on this for a couple of years and the prototypes
> were getting good reviews from early testers. Apple was peripherally
> involved with the ARM since it had decide the Hobbit/CRISP that had
> been intended for what became the Newton was no good; around then
> Acorn, Apple and VTI formed ARM  Ltd. Interestingly enough a little
> company in silicon valley decided to use the Hobbit for their attempt
> at a tablet; eventually they realised that the Active Book was much
> better and bought out the owners. And just junked everything. Oh, yes,
> that was ATT, who had created that dreadful thing called PenPoint and
> the tablet that ran it. It never went anywhere. I had one for a while.
> Dreadful; slow as... well about as slow as a lot of modern machines
> when they haven't enough memory, despite their adverts claiming how it
> was so fast because of the carefully hand optimised code.
>
> Oh, we should note that in the same time period there was another
> tablet machine around that happened to be based on Digitalk's
> Smalltalk; the Momenta.