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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Seeking AT&T 6300 IRQ, DMA and BIOS Information

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    Seeking AT&T 6300 IRQ, DMA and BIOS Information

    1. Is there a DOS program that can read the IRQ table and the DMA listing to show interrupts and addresses are assigned to an AT&T 6300 XT type computer system using DOS 6.22? I am looking for board conflicts.

    2. Is there anyway convert BIOS EPROM code back to assembly or basic or whatever was used to create it. I have a problem with parallel printing on an AT&T 6300 computer. I never had this issue before I upgraded my BIOS from version 1.21 to 1.43. I believe that there is some sort of error in the BIOS code keep in the BUSY line high or 1 even with no cable or loopback attached. I can see the BUSY line being high by using the Microsoft Diagnostics version 3 tool. I downloaded the 1.43 BIOS upgrade from the AT&T 6300 Shrine website. I am at a loss to determine why the parallel port is not functioning.

    INFOPLUS (freeware) or CheckIt (there are old DOS versions floating around) should be able to do this for you in a basic sense, but it's better to inspect the boards you have and understand their dip switches/jumpers/etc. Is there something specific you're attempting that isn't working? We have some AT&T 6300 experts on the forum. Keep in mind that the AT&T 6300/Olivetti M24/Xerox 6060 have some hardware quirks, although keeping BUSY high is not one I'm familiar with.

    While there are ways to disassemble the BIOS, you're in luck, as both the original BIOS and the 1.43 BIOS sources are available:

    (moderators: move this thread to "PCs and Clones" if possible.)
    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)


      I know for a fact that Check-It's ability to suss out if an interrupt is being used and correctly attributing it is pretty much non-existent. For instance, on my Tandy 1000 which has several oddities like COM2 using IRQ2 instead of IRQ3 to free up the latter for a network card, the best its IRQ display can do is it's smart enough to figure out that COM2 *isn't* on IRQ3. (Which it labels as "free" even if I have the network card driver loaded.) It does say that a "Mouse" is using IRQ2 if I have the driver loaded, which is something, I guess.

      (It also claims that my "hard disk" is using IRQ5 even though I'm using an XT-CF card that doesn't use an interrupt; presumably it's doing so because that's standard for an XT. It also lists the standard DMA assignments for memory refresh, floppy, and fixed disk even though my machine *doesn't even have a DMA controller*.)
      My Retro-computing YouTube Channel (updates... eventually?): Paleozoic PCs Also: Blogspot


        To throw another wrench into the picture, it's possible for some devices to share interrupts with others--much depends on the device and the driver.
        Reach me: vcfblackhole _at_ protonmail dot com.


          Thank you for recommending the Checkit and InfoPlus programs they were helpful in determining the parallel port problem as being a cable-related problem. I had an older Centronics cable that allowed the testing of the printer to proceed. Checkit kept illustrating an error with my Commerical loopback connector for parallel. I replied no to the loopback test and everything passed. The printer test was successful. I'll have some questions regarding the VGA card that I have been writing about in another post. Thanks to all that responded to the post.


            Check-It! 3.0 came with both parallel and serial loopback plugs in the box and is likely expecting those in its testing. I'd like to hope they are all wired in a standard fashion, but you never know.