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

Unidentified XT Clone m/b

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

    #16
    Thanks for the tip. But no, it stays hung well beyond 5 mins. It also does the same with no drive or cables attached, which is probably normal.

    I'm getting on better with the floppy drives though. It seems my NOS main boot disk was flaky. The second drive is reliable with disks that it formatted itself, so suspect alignment. And the better drive seems to read factory retail disks pretty well. With the right disks in the right drive(s) it's happy and I can get it to boot every time.
    http:\\www.QXL.WIN
    I'm Chris. I have a small collection of old IBM compatibles and a getting-rather-large collection of Sinclair QL related hardware and software items. Always on the look out for QL stuff if anyone has anything.

    Comment


      #17
      Originally posted by Chr$ View Post
      Thanks for the tip. But no, it stays hung well beyond 5 mins. It also does the same with no drive or cables attached, which is probably normal.
      Normal for an XT-class HDD controller is that it issue a 1701 error after a timeout, i.e. allow the boot process to continue.
      I have an ST10 card (with v2.4 BIOS) in storage. I will dig it out and see how it behaves with no cables/drives attached.

      Comment


        #18
        Originally posted by modem7 View Post
        Normal for an XT-class HDD controller is that it issue a 1701 error after a timeout, i.e. allow the boot process to continue.
        I have an ST10 card (with v2.4 BIOS) in storage. I will dig it out and see how it behaves with no cables/drives attached.
        Thanks very much. I did try it with the ERSO v2.42 BIOS, just in case, but it made no difference except the ST10 v2.4 message comes after the initial few lines of text, and then it hangs again. I did also check the BIOS on the ST10 card and that matches exactly the v2.4 BIOS on your website.

        Another issue is now getting the Fountain Technologies Inc MFT-384 multifunction card RAM to be seen. The m/b has 256k fitted and when I set the card to start at 256k (the same settings it came with) it is simply not seen but some of the card RAM chips do get a little warm. I have also read that the m/b may not be capable of having more than 256k. Or well, it's all good fun.
        http:\\www.QXL.WIN
        I'm Chris. I have a small collection of old IBM compatibles and a getting-rather-large collection of Sinclair QL related hardware and software items. Always on the look out for QL stuff if anyone has anything.

        Comment


          #19
          Originally posted by Chr$ View Post
          Another issue is now getting the Fountain Technologies Inc MFT-384 multifunction card RAM to be seen. The m/b has 256k fitted and when I set the card to start at 256k (the same settings it came with) it is simply not seen but some of the card RAM chips do get a little warm. I have also read that the m/b may not be capable of having more than 256k. Or well, it's all good fun.
          I have just now replied in that thread.

          Comment


            #20
            Originally posted by modem7 View Post
            Normal for an XT-class HDD controller is that it issue a 1701 error after a timeout, i.e. allow the boot process to continue.
            I have an ST10 card (with v2.4 BIOS) in storage. I will dig it out and see how it behaves with no cables/drives attached.
            Originally posted by Chr$ View Post
            Thanks very much. I did try it with the ERSO v2.42 BIOS, just in case, but it made no difference except the ST10 v2.4 message comes after the initial few lines of text, and then it hangs again. I did also check the BIOS on the ST10 card and that matches exactly the v2.4 BIOS on your website.
            I located my ST10 card. I put it into my IBM 5160 (IBM XT). No cables connected to it. Shortly after the 5160's POST completed its memory count-up, the ST10 displayed "ST10 v2.4", then about 45 seconds later, the ST10 displayed "1701 (04)". I was then prompted by the 5160's POST to press the F1 key to continue.

            Comment


              #21
              Hmmm, I suppose that confirms my card has an issue. I'll see if there is physically anything obviously wrong with it.
              http:\\www.QXL.WIN
              I'm Chris. I have a small collection of old IBM compatibles and a getting-rather-large collection of Sinclair QL related hardware and software items. Always on the look out for QL stuff if anyone has anything.

              Comment


                #22
                After gently retrobriting the front plastic part outside in hazy sun and clouds for 3 days, the empty case now looks like this. There is still a slightly lighter patch where there was once a sticker, but I didn't want to over-do it and I'm very pleased with how it came out. For direct comparison, the first pic is the seller's pic, as purchased. The rest are from just now.
                You do not have permission to view this gallery.
                This gallery has 5 photos.
                http:\\www.QXL.WIN
                I'm Chris. I have a small collection of old IBM compatibles and a getting-rather-large collection of Sinclair QL related hardware and software items. Always on the look out for QL stuff if anyone has anything.

                Comment


                  #23
                  Did you use cream or liquid for the retrobrite?

                  Comment


                    #24
                    Originally posted by jafir View Post
                    Did you use cream or liquid for the retrobrite?
                    Liquid, after dilution probably only about 6-9% H2O2. In a plastic tub big enough to submerge the whole piece, weighed down with a glass jar full of nails resting on it, tub covered over with clear plastic and the whole thing on a black base.
                    http:\\www.QXL.WIN
                    I'm Chris. I have a small collection of old IBM compatibles and a getting-rather-large collection of Sinclair QL related hardware and software items. Always on the look out for QL stuff if anyone has anything.

                    Comment


                      #25
                      BTW, looking at the picture of your board, if you notice, your board seems to say "p2164-20 or hm50256-20" next to the ram, which suggests it should be able to take 256k ram chips in the first bank as-is. (Just set the dip switch the same as you would on any other IBM or clone. If I am reading the on/off marking right, mine are set to 1:ON 2:ON 3:ON 4:ON 5:OFF 6:ON 7:ON 8:OFF, I don't recall what video card I had in there last).

                      Also, your u39 socket (next to the dip switches) is empty. On mine it is filled with a SN7407. At a glance it looks like U39 has connections to the dip switch - might be part of your problem here.

                      My board also says "OEM/PC REV B1" on the back.

                      Comment


                        #26
                        Originally posted by SomeGuy View Post
                        BTW, looking at the picture of your board, if you notice, your board seems to say "p2164-20 or hm50256-20" next to the ram, which suggests it should be able to take 256k ram chips in the first bank as-is.
                        That was my thinking too. I only have 16x 256k chips at the moment. The U39 chip was showing as bad in my MiniPro so I ordered an NOS one - which also showed as bad so I assumed for now that the MiniPro is unable to test them and put the original one back in. I suppose they could both really be bad.

                        Switches 3&4 relate to RAM. With both on I only ever get 64k showing. With both off I get 256k max, and then if I e.g. remove a chip from bank 4 then it counts to 192k and with a chip from bank 3 also missing it's 128k as expected.

                        I tried debug but it shows everything above 4000:0 as being FF and it cannot be changed, so as if there was nothing there - both with or without the RAM card fitted. I also tried other higher addresses and it's all just unchangeable FF's.
                        http:\\www.QXL.WIN
                        I'm Chris. I have a small collection of old IBM compatibles and a getting-rather-large collection of Sinclair QL related hardware and software items. Always on the look out for QL stuff if anyone has anything.

                        Comment


                          #27
                          I discovered a failed 74xx logic chip on my RAM expansion card. I replaced it and I think I was getting somewhere until parity errors kept appearing after I played with a jumper I probably shouldn't have. Even with no RAM chips in the card and all related switches turned off, if was very unstable (but fine without the card attached) - another 2 74xx's had failed. Hmmm, wonder if something is causing them to die or perhaps due to heat because of all the battery repair bodges. The other card functions are fine with the dead chips removed. I've ordered replacements. Will see how that goes.

                          And something more pleasing - I made up a logo for the blank badge space on the front of the case, based on the original DTC logo. Looks great.
                          You do not have permission to view this gallery.
                          This gallery has 1 photos.
                          http:\\www.QXL.WIN
                          I'm Chris. I have a small collection of old IBM compatibles and a getting-rather-large collection of Sinclair QL related hardware and software items. Always on the look out for QL stuff if anyone has anything.

                          Comment


                            #28
                            Originally posted by modem7 View Post

                            I located my ST10 card. I put it into my IBM 5160 (IBM XT). No cables connected to it. Shortly after the 5160's POST completed its memory count-up, the ST10 displayed "ST10 v2.4", then about 45 seconds later, the ST10 displayed "1701 (04)". I was then prompted by the 5160's POST to press the F1 key to continue.
                            If you still have it handy modem7, what is the resistance between gnd and 5v on your ST10 card? My multimeter shows it as a short, when in actual fact it's 45ohms. Seems very low!
                            Last edited by Chr$; September 4, 2021, 08:35 AM.
                            http:\\www.QXL.WIN
                            I'm Chris. I have a small collection of old IBM compatibles and a getting-rather-large collection of Sinclair QL related hardware and software items. Always on the look out for QL stuff if anyone has anything.

                            Comment


                              #29
                              45 ohms?

                              That means a 111 ma draw on the 5 volt line--that's not unreasonable for a hard disk controller.
                              Reach me: vcfblackhole _at_ protonmail dot com.

                              Comment


                                #30
                                Originally posted by Chuck(G) View Post
                                45 ohms?

                                That means a 111 ma draw on the 5 volt line--that's not unreasonable for a hard disk controller.
                                Thanks for the clarification. I'll get out my oscilloscope and see if anything is stuck. Am a bit lost with it ATM.
                                http:\\www.QXL.WIN
                                I'm Chris. I have a small collection of old IBM compatibles and a getting-rather-large collection of Sinclair QL related hardware and software items. Always on the look out for QL stuff if anyone has anything.

                                Comment

                                Working...
                                X