Forum Rules and Etiquette

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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
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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.
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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:
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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
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IBM PS/2 Model 25 - Green Screen on Boot, No Post

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    IBM PS/2 Model 25 - Green Screen on Boot, No Post

    Hello all!

    Forgive me if this is already posted elsewhere, but Iím having trouble getting an old PS/2 Model 25 (8086) to boot up after digging it out of the closet. When I flip the power switch, the unit powers up (including power being fed to an add-on IDE hard disk attached to an expansion card that also feeds it power), but never actually posts, only displaying a dancing green screen. I took a look at the motherboard, reseated expansion cards and RAM, but donít see anything terribly out of order, at least by my uninformed eye. Any one have any thoughts, tips, suggestions, or resources I can check out?


    That's a tough one. If you had a vintage POST card ( ) you could set it to port 90h and see if you're getting any codes at all from the BIOS. Past that, you'll need to hunker down with the hardware maintenance manual:
    Offering a bounty for:
    - A working Sanyo MBC-775 or Logabax 1600
    - Music Construction Set, IBM Music Feature edition (has red sticker on front stating IBM Music Feature)


      Thank you, Trixter! I donít have an illustrious POST card, (didnít realize they even existed!) but Iíll cozy up to the maintenance manual and hopefully report back with progress!


        the monitor should NOT be green like that, all my 25's have a black screen (both b&W and color)

        It looks like a hardware failure either in the crt potion or in the video card. IBM is pretty good about having on-screen error codes, and if you solve the green crt issue, it might be telling you about the error as to why its not booting.
        It is a mistake to think you can solve any major problems just with potatoes.


          Thank you, luckybob! That's sort of what I'm afraid of ... I feel like the CRT is beyond my abilities to remedy and I'm not optimistic about scouring for a replacement motherboard, though I suppose that might be the lesser of the two evils?


            Alsoónot sure where the angry emoji is coming from, I appreciate everyone's feedback so apologies on that slipping in there!


              As far as my own personal knowledge with fixing CRT screens, i'd classify my self in the category of 'knows enough to be dangerous".

              If I were in your position, i'd isolate the fault first. if you unplug the monitor from the motherboard and turn on the pc, does the image change? If the screen stays black, it would lead me to troubleshoot the monitor. If the screen remains green, I'd start to troubleshoot the crt.

              In addition, you can make your own 2x5 header -> vga cable adapter. one of the members here has done it, and made a video about the process. I don't recall exactly which member he is here, but hopefully he will be kind enough to chime in. Worst case scenario, just search this site, it should come up.

              In most cases with the CRT, its bad caps that cause things to go all cactus. The fact the screen still comes up green, to me, is a good thing. It means the high voltage is working, and I'd wager the issue is in the "low" voltage side of the CRT. (if it is indeed the CRT).

              As for troubleshooting the motherboard (if it is the cause), check the easy stuff first. Is the power supply supplying the proper voltages? (while under load) re-seat all the parts you can, look for obvious broken parts.
              Last edited by luckybob; April 3, 2020, 03:09 PM. Reason: because proofreading is hard!
              It is a mistake to think you can solve any major problems just with potatoes.


                Originally posted by luckybob View Post
                In addition, you can make your own 2x5 header -> vga cable adapter. one of the members here has done it, and made a video about the process. I don't recall exactly which member he is here, but hopefully he will be kind enough to chime in. Worst case scenario, just search this site, it should come up.
                That would be me.

                My Model 25 has randomly started doing this actually itself, WITH a VGA card mind you (and grey because it's a black and white model). So far I've pointed at least my particular issue to the power good signal not going high, indicating some PSU issues. If you have a multimeter check the power connector for power good, that will be pin 1. If it's not that though, it could be a number of things and as mentioned a POST card would be needed since you're not getting any video output.
                IBM PS/2 Model 25, NEC V30 8MHz, 640KB RAM, ATI VGA Wonder XL, 2GB SSD, Ethernet, DR DOS 6/GeOS, Xircom PE3 Ethernet