DistOS 2014W Lecture 5

Introduction

Operating system

The software that turns the computer you have into the one you want (Anil)

• What sort of computer did we want to have?
• What sort of abstractions did they want to be easy? Hard?
• What could we build with the internet (not just WAN, but also LAN)?
• Most dreams people had of their computers smacked into the wall of reality.

MOAD review in groups

• Chorded keyboard unfortunately obscure, partly because the attendees disagreed with the long-term investment of training the user.
• View control → hyperlinking system, but in a lightweight (more like nanoweight) markup language.
• Ad-hoc ticketing system
• Ad-hoc messaging system
  • Used on a time-sharing systme with shared storage,
• Primitive revision control system
• Different vocabulary:
  • Bug and bug smear (mouse and trail)
  • Point rather than click

Class review

• Doug died Jul 2 2013
• Doug himself called it an “online system”, rather than offline composition of code using card punchers as was common in the day.
• What became of the tech:
  • Chorded keyboards:
    • Exist but obscure
  • Pre-ARPANET network:
    • Time-sharing mainframe
    • 13 workstations
    • Telephone and television circuit
  • Mouse
    • “I sometimes apologize for calling it a mouse”
  • Collaborative document editing integrated with screen sharing
  • Videoconferencing
    • Part of the vision, but more for the demo at the time,
  • Hyperlinks
    • The web on a mainframe
  • Languages
    • Metalanguages
      • “Part and parcel of their entire vision of augmenting human intelligence.”
      • You must teach the computer about the language you are using.
      • They were the use case. It was almost designed more for augmenting programmer intelligence rather than human intelligence.
    • It was normal for the time to build new languages (domain-specific) for new systems. Nowadays, we standardize on one but develop large APIs, at the expense of conciseness. We look for short-term benefits; we minimize programmer effort.
    • Compiler compiler
  • Freeze-pane
  • Folding—Zoomable UI (ZUI)
    • Lots of systems do it, but not the default
    • Much easier to just present everything.
  • Technologies the required further investment got left behind.
• The NLS had little to no security
  • There was a minimal notion of a user
  • There was a utopian aspect. Meanwhile, the Mac had no utopian aspect. Data exchange was through floppies. Any network was small, local, ad-hoc, and among trusted peers.
  • The system wasn't envisioned to scale up to masses of people who didn't trust each other.
  • How do you enforce secrecy.
• Part of the reason for lack of adoption of some of the tech was hardware. We can posit that a bigger reason would be infrastructure.
• Differentiate usability of system from usability of vision
  • What was missing was the polish, the ‘sexiness’, and the intuitiveness of later systems like the Apple II and the Lisa.
  • The usability of the later Alto is still less than commercial systems.
    • The word processor was modal, which is apt to confuse unmotivated and untrained users.
• In the context of the Mother of All Demos, the Alto doesn't seem entirely revolutionary. Xerox PARC raided his team. They almost had a GUI; rather they had what we call today a virtual console, with a few things above.
• What happens with visionaries that present a big vision is that the spectators latch onto specific aspects.
• To be comfortable with not adopting the vision, one must ostracize the visionary. People pay attention to things that fit into their world view.
• Use cases of networking have changed little, though the means did
• Fundamentally a resource-sharing system; everything is shared, unlike later systems where you would need to explicitly do so. Resources shared fundamentally sense to share: documents, printers, etc.
• Resource sharing was never enough. Information-sharing was the focus.

Alto review

• Fundamentally a personal computer
• Applications:
  • Drawing program with curves and arcs for drawing
  • Hardware design tools (mostly logic boards)
  • Time server
• Less designed for reading than the NLS. More designed around paper. Xerox had a laser printer, and you would read what you printed. Hypertext was deprioritized, unlike the NLS vision had focused on what could not be expressed on paper.
• Xerox had almost an obsession with making documents print beautifully.