Announcement

Collapse

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

Is an IBM 5155 Motherboard JUST an XT Motherboard or just equivalent?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Is an IBM 5155 Motherboard JUST an XT Motherboard or just equivalent?

    Exactly like the title says...

    I've heard that an IBM 5155 is essentially an XT with a built-in monitor and smaller form factor. However, what I'm not sure of is the following:

    Did manufacturers make motherboards specifically for the IBM 5155, or did they just simply produce XT motherboards to be placed in 5155 cases to be shipped to customers (with the relevant expansion cards)?

    If yes, I've half a mind to buy just the 5155 case/CRT, an XT motherboard, and "create" a 5155 of my own :P.*

    *Not really, but those things are expensive- and they typically don't even come with the keyboard!
    Looking for: Needham's Electronics PB-10 Microcontroller Adapter (looking for one since early 2012!).

    #2
    Your right. The 5155 is the same motherboard as the IBM 5160.

    The 5155 has only a different case for easy transportation. It has less rome for expansion cards so its a bit less practical but they are both the same computers.

    Comment


      #3
      IBM should've called it the Portable XT, because calling it the Portable PC led a lot of people to mistakenly believe that it had the 5150 PC motherboard inside. And it really deserved a better video card, because its grainy, snowy monochrome CGA display put it at an immediately noticeable disadvantage compared to the Compaq Portable's crisp, clear, MDA/EGA-quality text display.

      Comment


        #4
        Of what I've heard, the XT was advertised as an improvement over the PC mainly by the inclusion of the HDD. The IBM 5155 didn't ship with a HDD, so if they called it a Portable XT people would get less than they'd expect.
        Current systems owned by me:
        Vintage:IBM PC/XT submodel 087 ( 1983 ), [Kon]tiki-100 rev. C (1983), Compaq Portable I ( 1984 ), IBM PC/XT submodel 078 ( 1985 ), IBM PC/XT286 ( ~1986 ), 3x Nintendo Entertainement Systems ( 1987 ).
        Obsolete:Commodore A500 ( ~1990 ), IBM PS/2 model 70/386 type 8570-161 ( 1991 ), Atari Lynx II ( ~1992 ), Generic Intel 486SX PC ( ~1993 ), AT/T Globalyst Pentium w/FDIV bug MB ( 1994 ), Compaq 486DX4 laptop ( ~1995 ).

        Comment


          #5
          Originally posted by cr1901 View Post
          If yes, I've half a mind to buy just the 5155 case/CRT, an XT motherboard, and "create" a 5155 of my own :P.*
          If you happened to find a 5155 case/CRT without a motherboard, that would work fine and would be relatively authentic.

          Comment


            #6
            Originally posted by SomeGuy View Post
            If you happened to find a 5155 case/CRT without a motherboard, that would work fine and would be relatively authentic.
            Sounds good! Except then I'd have to find the keyboard as well, since it appears to use an RJ11 connector. How does the keyboard connector on the XT connect to the front of the case of a Portable?
            Looking for: Needham's Electronics PB-10 Microcontroller Adapter (looking for one since early 2012!).

            Comment


              #7
              Originally posted by cr1901 View Post
              How does the keyboard connector on the XT connect to the front of the case of a Portable?
              Refer to the 'inside view' photo at the web site [here]. You can just make out the cable that runs from the RJ socket to the motherboard's keyboard connector.

              Comment


                #8
                My understanding is that auto-parking drives didn't arrive until significantly after the 5155 was released, hence the FDD only option.

                Comment


                  #9
                  Originally posted by pearce_jj View Post
                  My understanding is that auto-parking drives didn't arrive until significantly after the 5155 was released, hence the FDD only option.
                  That and they were generally quite fragile. I have to invoke a park command before I turn mine off.
                  [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

                  Comment

                  Working...
                  X