DistOS 2023W 2023-01-23

Discussion questions

Remember, these are just to get you started. Please allow your discussion to go where it will, so long as it is somewhat related to the readings.

How distributed was the Mother of All Demos?
How distributed was the Alto?
How did the demo actually work? What was the system capable of?
What could the Alto do? On what sort of hardware?
How do these systems relate to the topics of this class?
What did you find interesting? Surprising?
Are there any ideas here that seem promising but we've "forgotten" about?

Notes

Lecture 5
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Significance of MOAD?
 - really was a glimpse of the future, blew people there away
 - *so* far ahead

But how real was it?
 - how much of it was on the computers?
    - video/audio? NO, was closed-circuit cameras/audio
    - graphics was overlays, not from the computer
 - how distributed was the computer part?
    - all running on one computer
    - communication was over dedicated data links (courtesy of the phone network), just providing serial connections for keyboard & mouse
    - (text) video was remotely projected
 
Much of the development of the Internet was an attempt to reach the vision of MOAD
 - and note it envisioned a distributed system on which everyone worked and
   could share data, and that would require distributed OS services

So what was the Alto, in relation to the MOAD?
 - people from Englebart's lab ended up at Xerox PARC

Technologies invented at Xerox PARC
 - ethernet
 - laser printers
 - GUIs
 - smalltalk (not first, but groundbreaking object-oriented programming)

Windows & Macintosh (well, the Lisa) were inspired directly by the Alto
 - note the original Mac didn't really do networking, didn't seem like such a big deal relative to GUIs and laser printers (desktop publishing)

Did they have a "distributed OS" at Xerox PARC? No, but they saw the benefit in trying to get networked computers to work together as "one system"
 - print servers
 - file servers
 - whole idea of "workgroup computing", where every individual would
   have their own computer but those computers could share network resources

The idea of having most of a computer's resources devoted to making an interface was revolutionary and controversial


Objective-C is Smalltalk + C
 - used by NeXT, formed basis of MacOS X

The Alto, and the tech developed at PARC, showed the possibility of personal computers when they were connected to a network.
 - Distributed OSs are an extension of that vision
 - collaboration & personal empowerment

The thing about a "bicycle for the mind" is that it assumes you know how to ride a bicycle
 - that requires training
 - the systems that succeeded in the marketplace required almost
   no training initially, could be used in a basic way very quickly
   (or seemed like they could)

This effort to make things "easy to use" isn't just for end users, it also applies to developers
 - we often want to be able to use systems immediately without investing
   any time learning new ways of doing things
 - developers are just as much like this as are regular users
 - Distributed OS started off trying to make things "easy to use",
   be just like what developers knew already (UNIX)
 - only later did they do things differently in order to maximize the power
   of the system