Dropping a Dynabook: A comic that turned from Science Fiction to Science Fact

Some time around 1982, I saw an amazing comic on the wall of a Xerox Alto computer room at the MIT AI Lab. Given the subject matter, I assume the comic was originally created at Xerox PARC, possibly as part of the NoteTaker project, but can't find any trace of it on the web. I have recreated it from memory, below.

The comic is explaining the events that happen when a Dynabook is accidentally dropped off the top of Half Dome in Yosemite National Park. Note that a free-fall calculator claims that it would take over 12 seconds for the Dynabook to hit the Yosemite Valley floor.

T+00.000 Dynabook accidentally dropped from top of Half Dome.

T+00.016 Dynabook notices that
  • It can't sense its user.
  • It is in zero gravity.
  • There is a 200 MPH wind from below.
Dynabook concludes that it is falling.
  • Turns off the display to save memory. 
  • Opens a radio connection to El Capitan radio tower.
  • Begins backing up the user's recent changes.

T+05.000 Dynabook hits a glancing blow to the side of Half Dome, breaking 3 of its 6 CPUs. The Dynabook reconfigures itself to continue working with the 3 remaining CPUs.

T+10.000 User data backup finishes.

T+11.000 Dynabook orders the user a replacement Dynabook.

T+12.000 Dynabook turns on an emergency locator beacon.

T+12.816 Dynabook smashes into the rocks at the bottom of Half Dome.

--------=====--------

When I first read this comic, probably a few years after it was created, it was total Science Fiction:

  • Laptops weighed 25 pounds, contained miniature CRT monitors, and had to be plugged in to operate.
  • Personal computers had single cores and no environmental sensors.
  • Mobile phones weighted multiple pounds and didn't have cellular modems. Yosemite Valley didn't have cell service.
  • Simply connecting to the Internet (then called the ARPANET) took over 30 seconds.
  • Data flowed at a blistering 1440 bytes per second.
  • Nobody in their right mind would take a fragile laptop to the top of Half Dome.
  • Commercial use of the Internet was prohibited. While hobbyists bought and sold stuff,  large companies, even computer makers, were not set up to allow products to be ordered over the Internet.

Over the years, each time I remembered this comic, I realized that it was becoming more and more science fact. By now, 40 years later, almost all of the events mentioned in this comic could actually happen as described.

To my mind the only unlikely events are:

  • In 1979 frame buffers were a significant fraction (more than 75%) of a computer's RAM, so it made sense to turn off the display to save memory. Today we would still turn off the display, but we would do it to save power.
  • In 1979 Moore's Law hadn't been in effect as long. A multi-core CPU had to be made out of separate CPU chips, such that one or more cores could plausibly be damaged without destroying all the chips. Today we do use multiple cores (indeed, typically 6-8), but they are all on one giant chip.
The only remaining Science Fiction idea is the rescue beacon. But Apple is rumored to be implementing that this year.





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