computer science

PicoSpan

PicoSpan is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand PicoSpan rather than just read about it. In short: PicoSpan was a popular computer conferencing tool written by Marcus D. Watts for the Altos 68000.

Key takeaways

PicoSpan belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect PicoSpan to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of PicoSpan from memory before moving on to harder problems.

Reference excerpt

PicoSpan was a popular computer conferencing tool written by Marcus D. Watts for the Altos 68000. It was written in 1983 for M-Net, which was owned and operated by Mike Myers. Sometime in 1984, Marcus's employer, an Ann Arbor company called Network Technologies International (NETI), purchased the rights for PicoSpan planning to develop it into a commercial product called E-Forum.

History Computer conferencing was first pioneered in Michigan on CONFER, PicoSpan, E-Forum, Caucus and Participate.

Functionality and impact PicoSpan tried to provide CONFER's functionality while using the least amount of resources, though many users found it hard to use. It formed the basis for many conferencing systems run by hobbyists. and commercial ventures Picospan came with a toolbox of software customization utilities that could be used to make changes at the system and user level. It was tightly integrated with Unix and could provide transparent access to many external programs that formed a part of the Unix environment. Typing "unix" at the Pico prompt put the user in a shell and users could rapidly switch back and forth and move text from one to the other. PicoSpan also permitted the linking of discussion threads into multiple conferences, at the same time, so that multiple groups could participate. On a big BBS with many users, not all conferences are followed, so it's advantageous if the more interesting discussions are cross-linked. PicoSpan also displays responses as a single integrated thread rather than a collection of separately displayed responses. It relied on constrained choices: no one could start a new topic merely by responding to an old post, so discussions and topics didn't fragment. You couldn't respond to an individual's post and had to respond to the whole thread, forcing people to stay coherent and on-topic. However many people found it hard to use, because of its plain-text environment and steep learning curve. Users normally dialed into the BBS over slow and flaky telephone lines. After providing the system with a name and password, they invoked Pico and brought up a long list of conference names like "Theology", "Arts", "Singles", "Twilight", "Health" and various other computer topics which were in turn grouped into themes like "Entertainment" or "Computers". The user could then type a command with the conference name as an argument and enter the conference. Once inside, they would find a series of numbered topics or threads each created by a user and each representing an asynchronous conversation. They could then post his comments. The WELL still provides Picospan access, via ssh, and the Engaged graphical interface still uses the Picospan database of Unix files. Marcus Watts had a direct effect on The WELL's culture: PicoSpan prevented censorship by preventing conference hosts (who are empowered to hide or delete any response posted in their forum) from influencing a discussion, by labeling such posts as being "<censored>".

References

External links Marcus D. Watts, Home Page

Worked examples

Example 1 — a first encounter with PicoSpan

Start with the simplest possible case. Write down what PicoSpan claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to PicoSpan before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about PicoSpan ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of PicoSpan

In research: PicoSpan appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses PicoSpan in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: PicoSpan is common in secondary-school and first-year university syllabi. It links to neighbouring topics Bulletin board systems, Defunct social networking services, History of the Internet, so understanding it makes those chapters shorter.
In everyday life: Look for PicoSpan outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study PicoSpan in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what PicoSpan means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain PicoSpan out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is PicoSpan in simple terms?

PicoSpan was a popular computer conferencing tool written by Marcus D. Watts for the Altos 68000.

Why does PicoSpan matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study PicoSpan?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on PicoSpan.