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.
See more
See less

Apple iie Platinum Garbled Screen Part 2

  • Filter
  • Time
  • Show
Clear All
new posts

    Apple iie Platinum Garbled Screen Part 2

    This is a continuation of a previous post on the same issue. Here is the first post:

    I have now installed new ram, it did help a little but it is still not functioning correctly.1.jpg2.jpg3.jpg4.jpg5.jpg5.jpg6.jpg

    Im definitely not too familiar with the Apple II line, in fact I have an II+ that I will need help on getting to post. But this seems to be an issue with the Character Rom. I havent read the previous posting, but was the character ROM checked?


      The character ROM is fine, the characters are wrong but are displayed perfectly.

      Its clear that the CPU is getting bad instructions, since RAM has been ruled out. There are some other candidates that can cause that issue.
      Check the +5v on the motherboard it should be between 5v and 5.25v but definitely not below 5v. Also check for AC ripple on the 5v line.
      If the power looks good check/replace the sockets on the board, in your first post you mention some signs of corrosion on some of the chips.

      I still think you should try the diag eprom I sent a link to, the results you get will narrow down the problem.


        I measured the voltages, +5v is at 5.1v but +12v measures only 11.13v. The only other thing is, I'm not quite sure how to measure for ac ripple. Sorry.


          To me, this just screams corrosion somewhere. I'd pull all the chips one by one, check for green fuzzies, and reinsert. I'd even go so far as to send the board through the dishwasher for good measure.

          Did you check the power supply UNDER LOAD? It makes a difference with these units I've noticed.
          It is a mistake to think you can solve any major problems just with potatoes.


            Originally posted by masterpigeon View Post
            I measured the voltages, +5v is at 5.1v but +12v measures only 11.13v. The only other thing is, I'm not quite sure how to measure for ac ripple. Sorry.
            To measure for AC ripple with a digital multimeter just set the meter to the AC range and it will filter out the DC component.
            11.13v is fine if there is no AC ripple on it, was the power supply under load at the time?


              I checked the voltages on the board once more, 12v measures 11.53v and 5v is still 5v. I don't believe there is any ac ripple with either of them. (It measured 0.004acv)


                Here is a picture of what the computer was doing after I reseated all the chips. it won't do anything else now, It only displays this screen. I also noticed something missing on the board while cleaning it.IMG_20180124_132105.jpgIMG_20180124_132503.jpg


                  Holy crap that pitting!
                  How much corrosion is going on all over that board?

                  Also CR2 is where an LED would normally sit. It is missing on your machine.
                  [Need something to waste time on? Click here to visit my YouTube channel CelGenStudios]
                  [No time for videos? Click here to visit my Twitter feed @CelGenStudios]

                  = Excellent space heater


                    wow, just wow.

                    That's a corrosion problem.
                    It is a mistake to think you can solve any major problems just with potatoes.


                      Here are some pictures of the board:


                      Apparently, the guy I got it from stored it in a leaky shed for several years and it must have gotten soaked because when I first picked it up, heaps of rust fell out. My table is still covered in it. Most of the metal base was rusted and heavily pitted but the board sort of looked ok but apperantly not. So that is why the board looks the way it does.


                        well... There isn't much to lose at this point.

                        Get some dish soap, a brush with long stiff bristles, and some super hot water. Go nuts. Hopefully it helps. I personally use Dawn soap.
                        It is a mistake to think you can solve any major problems just with potatoes.


                          The board has been washed! Now it's drying...


                            Well, soaking it didn't break it... nor did it fix it. It just changed it slightly.

                            It will display the bars or thin bars and eventually change to the '@' screen.


                              Well, I would have let that dried longer... In all likelihood there is a broken (or shorted) connection somewhere. Or a bad chip maybe. You might try over at they are more specialized on these systems.
                              It is a mistake to think you can solve any major problems just with potatoes.