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.





Comments

Post a Comment

Popular posts from this blog

GLES Quake - a port of Quake to the Android platform

I've just published the source code to a port of Quake to the Android platform . This is something I did a while ago as a internal test application. It's not very useful as a game, because there hasn't been any attempt to optimize the controls for the mobile phone. It's also awkward to install because the end user has to supply the Quake data files on their own. Still, I thought people might enjoy seeing a full-sized example of how to write a native code video game for the Android platform. So there it is, in all its retro glory. (Porting Quake II or Quake III is left as an exercise for the reader. :-) What's different about this particular port of Quake? Converted the original application into a DLL Android applications are written in Java, but they are allowed to call native languge DLLs, and the native language DLLs are allowed to call a limited selection of OS APIs, which include OpenGL ES and Linux File I/O. I was able to make the game work by using Java for: T...
Read more

A Taipei-Torrent postmortem: Writing a BitTorrent client in Go

This is a BitTorrent client. There are many like it, but this one is mine. -- the BitTorrent Implementer's Creed For fun I've started writing a command-line BitTorrent client in Google's go programming language. The program, Taipei-Torrent , is about 70% done. It can successfully download a torrent, but there are still lots of edge cases to implement. Go routines and channels are a good base for writing multithreaded network code. My design uses goroutines as follows: a single main goroutine contains most of the BitTorrent client logic. each BitTorrent peer is serviced by two goroutines: one to read data from the peer, the other to write data to the peer. a goroutine is used to communicate with the tracker some "time.Tick" goroutines are used to wake the main goroutine up periodically to perform housekeeping duties. All the complicated data structures are owned by the main goroutine. The other goroutines just perform potentially blocking network I/O using channel...
Read more

Writing an Android application in JavaScript and HTML5

Image
Happy Mother's Day everyone! This year I wrote an Android app for my wife for Mother's Day. How geeky is that? The reason I wrote it is that my wife's favorite Android application, Word Mix Lite, recently added annoying banner ads. While the sensible thing to do might have been to switch to another app, or perhaps upgrade to the paid version of Word Mix, I thought it might be interesting to see if I could write my own replacement. And as long as I was writing the app, I though I'd try writing it using JavaScript. Normally Android applications are written in Java, but it's also possible to write them in JavaScript, by using a shell application such as PhoneGap . Why use JavaScript instead of Java? Well, hack value mostly. On the plus side it's a fun to write! Another potential plus is that it is theoretically possible to run the same PhoneGap application on both Android and Apple. The drawback is that PhoneGap is not very popular yet, especially among Android dev...
Read more