Forum Rules and Etiquette

Our mission ...

This forum is part of our mission to promote the preservation of vintage computers through education and outreach. (In real life we also run events and have a museum.) We encourage you to join us, participate, share your knowledge, and enjoy.

This forum has been around in this format for over 15 years. These rules and guidelines help us maintain a healthy and active community, and we moderate the forum to keep things on track. Please familiarize yourself with these rules and guidelines.

Rule 1: Remain civil and respectful

There are several hundred people who actively participate here. People come from all different backgrounds and will have different ways of seeing things. You will not agree with everything you read here. Back-and-forth discussions are fine but do not cross the line into rude or disrespectful behavior.

Conduct yourself as you would at any other place where people come together in person to discuss their hobby. If you wouldn't say something to somebody in person, then you probably should not be writing it here.

This should be obvious but, just in case: profanity, threats, slurs against any group (sexual, racial, gender, etc.) will not be tolerated.

Rule 2: Stay close to the original topic being discussed
  • If you are starting a new thread choose a reasonable sub-forum to start your thread. (If you choose incorrectly don't worry, we can fix that.)
  • If you are responding to a thread, stay on topic - the original poster was trying to achieve something. You can always start a new thread instead of potentially "hijacking" an existing thread.

Rule 3: Contribute something meaningful

To put things in engineering terms, we value a high signal to noise ratio. Coming here should not be a waste of time.
  • This is not a chat room. If you are taking less than 30 seconds to make a post then you are probably doing something wrong. A post should be on topic, clear, and contribute something meaningful to the discussion. If people read your posts and feel that their time as been wasted, they will stop reading your posts. Worse yet, they will stop visiting and we'll lose their experience and contributions.
  • Do not bump threads.
  • Do not "necro-post" unless you are following up to a specific person on a specific thread. And even then, that person may have moved on. Just start a new thread for your related topic.
  • Use the Private Message system for posts that are targeted at a specific person.

Rule 4: "PM Sent!" messages (or, how to use the Private Message system)

This forum has a private message feature that we want people to use for messages that are not of general interest to other members.

In short, if you are going to reply to a thread and that reply is targeted to a specific individual and not of interest to anybody else (either now or in the future) then send a private message instead.

Here are some obvious examples of when you should not reply to a thread and use the PM system instead:
  • "PM Sent!": Do not tell the rest of us that you sent a PM ... the forum software will tell the other person that they have a PM waiting.
  • "How much is shipping to ....": This is a very specific and directed question that is not of interest to anybody else.

Why do we have this policy? Sending a "PM Sent!" type message basically wastes everybody else's time by making them having to scroll past a post in a thread that looks to be updated, when the update is not meaningful. And the person you are sending the PM to will be notified by the forum software that they have a message waiting for them. Look up at the top near the right edge where it says 'Notifications' ... if you have a PM waiting, it will tell you there.

Rule 5: Copyright and other legal issues

We are here to discuss vintage computing, so discussing software, books, and other intellectual property that is on-topic is fine. We don't want people using these forums to discuss or enable copyright violations or other things that are against the law; whether you agree with the law or not is irrelevant. Do not use our resources for something that is legally or morally questionable.

Our discussions here generally fall under "fair use." Telling people how to pirate a software title is an example of something that is not allowable here.

Reporting problematic posts

If you see spam, a wildly off-topic post, or something abusive or illegal please report the thread by clicking on the "Report Post" icon. (It looks like an exclamation point in a triangle and it is available under every post.) This send a notification to all of the moderators, so somebody will see it and deal with it.

If you are unsure you may consider sending a private message to a moderator instead.

New user moderation

New users are directly moderated so that we can weed spammers out early. This means that for your first 10 posts you will have some delay before they are seen. We understand this can be disruptive to the flow of conversation and we try to keep up with our new user moderation duties to avoid undue inconvenience. Please do not make duplicate posts, extra posts to bump your post count, or ask the moderators to expedite this process; 10 moderated posts will go by quickly.

New users also have a smaller personal message inbox limit and are rate limited when sending PMs to other users.

Other suggestions
  • Use Google, books, or other definitive sources. There is a lot of information out there.
  • Don't make people guess at what you are trying to say; we are not mind readers. Be clear and concise.
  • Spelling and grammar are not rated, but they do make a post easier to read.
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Distorted image

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    Distorted image

    [wiki="Fileistorted_Display.jpg"]200px|thumb|right|A Commodore PET display suffering from severe distortion.[/wiki]
    There are many forms of distortion on a [wiki]CRT[/wiki] display and just as many causes. Distortions can range from a subtle quivering to a completely illegible image.
    Loss of Sweep

    Under some conditions the beam will not scan across the display, either horizontally or vertically. On a color monitor this is a dangerous condition! DO NOT operate a CRT without sweep, it will damage a monochrome CRT and can become a severe safety hazard with a color CRT resulting in burn-through of the CRT face by the electron beam. Most CRTs won't do this in brief operation, but some will.
    If you wish to repair such a monitor, disconnect the CRT until the sweep circuits are repaired.
    Vertical distortion, horizontal or both?

    Distortion may be limited to one axis of the display. As each axis is controlled by separate circuitry, distortion in a single axis can help diagnose the origin of the problem. If distortion is present in both axes, it is probable that a faulty power supply is the cause.
    Distortion in one axis is often caused by failures in signal amplifier components for that axis, For example, a weak transistor in the vertical amplifier may result in an image which will not extend the full height of the display area, regardless of adjustments. Failure of the vertical amplifier may result in the image being only one scanline high in the center of the display. This can cause damage to the display.
    A weak transistor or failing capacitor in the sweep circuit of a raster display can result in an image that is compressed horizontally, or which does not trace the full width of the display.
    Power Supply

    Arcing or poor regulation in the power supply will cause erratic distortion of the display. Arcing is often accompanied by a snapping sound, though if the arcs are following carbon paths established by earlier arcs they may not be easily audible.
    Black or Bright Display

    A black or intermittently blanking display may be caused by a failed G1 output on the power supply. Normal output on a typical color CRT monitor will range from 0 to -90 volts. If the output stays at -90 volts it will block the electron beam, causing the display to go dark.
    If it fails at a voltage near 0 volts, it will fail to blank the display during video retrace, resulting in both horizontal and vertical retrace lines being seen on the CRT.

    The electron beam is normally focused for a fixed distance from the electron gun. To allow CRT screen to be flatter, a focus output adjusts its voltage as the beam sweeps across the screen to allow the beam to stay focused as the distance from gun to phosphor varies. If the display can be focused only across part of the display, like the center but not the edges, or the edges but not the center, then the focus circuit is the likely culprit.
    Focus outputs (400 to 1800V) are not as high a voltage as the anode voltage (usually 14,000 to 25,000VDC), but are high enough to be dangerous. The type of focus circuit used, and how flat the screen is (how much it varies from a sphere) will determine the focus voltage and its range of change.
    During proper operation, the focus voltage will start at one extreme when the beam is at the left edge of the display. It will swing to its other extreme at the center of the display, then back again as it reaches the right edge.
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