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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Hello from a Reluctant PET Owner

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    Hello from a Reluctant PET Owner

    Hello and thank you for having me. About thirty years ago I used to buy the occasional VIC 20, C64 or Spectrum from car boot sales when such things were unpopular and cheap. They were largely for the amusement of my children and although I'm a lifelong electronics hobbyist I never had to do much with the computers in terms of repairs. At the time I also acquired a non-working PET 2001-8 with calculator style keyboard which typically just displayed the frozen random character (garbage) screen at switch-on. Life was hectic back then so I'm afraid the PET lay untouched until earlier this year when I decided to see if it could be revived. The original intention was simply to get it working and then pass it on to someone with a greater interest in vintage computing. However during the restoration process I got hooked! So I'm here to learn more and hopefully pass on a few tips to anyone else faced with a non-working early PET. I should say that my knowledge of logic circuits and low level programming is still basic to say the least.


    Hello Alan and welcome to the forum - you have come to the right place for repairing a PET!

    Yes, you can get hooked easily !

    So, first things first, have you found the documentation treasure-trove over at

    Second, what test equipment do you have? For example: a basic multimeter, a logic probe, and oscilloscope?

    Do you have an EPROM programmer?

    I wrote some test firmware for the PET a few years ago that you can program into an EPROM and pop in place of the EDIT ROM.

    What devices on the main board are socketed?

    You didn't actually say whether you got your PET working or not (now I re-read your post).

    By the way, you will be moderated for the first 10 posts or so - so we will have to wait for the moderators to have a sensible conversation about repairs. Just post now and then and the overworked (and underpaid) moderators will eventually let you fly on your own.

    You also ought to be aware that the private messaging system on the forum got 'screwed up' when we up (down) graded the board - so I would advise caution in using it. You generally get blank messages! As much use as a chocolate teapot in fact!



      Thank you for the warm welcome Dave and for the advice about the forum.

      I'm sorry I didn't make it clear that the PET is now fully functional. Luckily I didn't need much more than a DMM and an oscilloscope to track down a number faults. Fortunately the 6540 ROM chips weren't the cause of the problems so an EPROM programmer wasn't required.

      I've been a member of the UKVRR&R forum for many years and, as you may know, there are a small group of contributors there who are interested in vintage computing. Their guidance and encouragement was invaluabe. However now I've become more interested in the PET and how it works I thought it would be logical to join this forum as well.

      Primarily for my own amusement, I've written up my experiences with the PET into the form of a booklet with photographs. It's all quite basic but I could post a Dropbox link to the file (it's quite large) if people think it would be of any interest to members here?



        Congratulations on fixing your PET then! Another one saved from oblivion...

        A DMM and an oscilloscope is pretty much the requisite test equipment. For the really stubborn PETs, a simple logic analyser makes things much easier - but those faults come along vary rarely.

        The EPROM programmer would have been of use to burn my test firmware into an EPROM. My test firmware doesn't require working RAM to run the initial tests - and then starts to run an exhaustive test on the RAM itself. However, a couple of members have developed a 6502 adapter card and loaded my test firmware onto that (along with a load of other nice goodies)...

        Yes, a few of the UKVRR&R members are on here as well...

        Yes, always interested to read of other's stories and experiences.

        If there are any specific questions you have about the PET and how it works, ask away !



          Probably best if I create a new topic in the forum's Commodore section with a link to the restoration story PDF.



            "PET owner" and "programming is still basic", I see what you did there.

            Also hello and welcome to the club
            Last edited by robert_sissco; November 23, 2021, 05:54 PM.