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

Installing core backplane into PDP 11/40

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

    #16
    Quick update - I have come to the conclusion that either ALL of my RAM is bad or there is an issue with the CPU memory management and parity RAM (MF11-UP). I am pretty sure power is ok and basic CPU operations are fine. I can save little programs like chase the lights into any spot in core memory, power off, power on, and run them. The problem is when I exam through 15-20 addresses or attempt something that manipulates memory. I get parity errors (parity light on the parity card M7259) , even though the data is in memory. The related manuals are pretty clear, but complex. I have a lot of things to check over (CPU, RAM, Options). I don't think the issue is with the M7259 falsely reporting parity errors. I am thinking there must be a CPU jumper expecting one kind of RAM or an option card different to what is actually installed. Not all of the components I have in the system are from the same place.

    When I have something to report I will. Just so you know I have not given up, but for the past few days I have not made much progress, other than a lot of card swapping and notes.

    b
    Last edited by billdeg; May 31, 2016, 06:01 PM.
    @ BillDeg:
    Web: vintagecomputer.net
    Twitter: @billdeg
    Youtube: @billdeg
    Unauthorized Bio

    Comment


      #17
      figured out the problem(s). I was starting the memory address toggle-in program from the wrong start location. Once I figured that out I was golden. Moving along, I hope to repair my serial card, or I will replace with another one. Ultimately I'd like to have two serial cards.
      @ BillDeg:
      Web: vintagecomputer.net
      Twitter: @billdeg
      Youtube: @billdeg
      Unauthorized Bio

      Comment


        #18
        The RICM is picking up a donated PDP-11/40 next week. We may have questions...
        Member of the Rhode Island Computer Museum
        http://www.ricomputermuseum.org

        Comment


          #19
          Hi All;

          Bill, as You already know, I have made that Kind of Mistake many a time before..
          Glad You Found it !! If nothing else, it makes You feel good, that You are making progress..

          THANK YOU Marty

          Comment


            #20
            after giving up on the M7856 I had been using (it receives but does not send back to the terminal), and an M7800 I hoped might work (bombs when attempting to do much of anything), I found another M7856, jumpered that one and now I am back in business. I have now 16K core, serial comms and a M9312 ROM/Terminator with RL01/2 and CONSOLE ROMs. Basically I am back where I was before with MOS RAM. The project was to expand the backplane and replace MOS with core RAM. NEXT - get RT11 running.

            As far as the original M7856 serial card goes, it appears to have been repaired more than once, some of the traces are bare, simply replacing the 1488/89 is not enough. I can compare the working card with the bad one, that should help diagnose/fix.
            @ BillDeg:
            Web: vintagecomputer.net
            Twitter: @billdeg
            Youtube: @billdeg
            Unauthorized Bio

            Comment


              #21
              I took a different DL11 (M7800) and got that running too. This thread has a lot of useful info about the DL11 M7800:

              http://vintagecomputer.net/browse_thread.cfm?id=641
              @ BillDeg:
              Web: vintagecomputer.net
              Twitter: @billdeg
              Youtube: @billdeg
              Unauthorized Bio

              Comment


                #22
                Hi Bill;

                I just found Your posting of running CKBB, and I have a couple of comments..
                First, You didn't let it Run nearly Long enough..
                Second, You need to patch address '3604 from an '000007 to a '000052, so it will Print a STAR when it makes a single Pass..
                It is easiest to do this from PDPGUI after You have Loaded the program into PDPGUI, but before You Load it into Your 11/40, after You have Patched it using PDPGUi then, Load the 11/40 and it will be ready to Run..
                Then Run it on the /40 and WAIT for the Stars to appear on the Screen.. (Assuming everything is OK ).. Give it 3 to 5 minutes per pass, Depending on the Amount of Memory You have in Your machine, and the speed of Your machine.. Maybe longer, since Your Machine is slower than mine..
                Also, Note that the First Star Doesn't count, only the Second Star and following.. And that both Fritzm, and I have listed where to find the 'Bell' and where to change it to '000052, and the Bell might be either an '000007 or an '000207..

                THANK YOU Marty
                Last edited by Marty; July 19, 2016, 03:55 PM.

                Comment


                  #23
                  I will give it a try. The program ran for at least 30 mins before I stopped it but I will try your patches to see what effect it has, thanks
                  @ BillDeg:
                  Web: vintagecomputer.net
                  Twitter: @billdeg
                  Youtube: @billdeg
                  Unauthorized Bio

                  Comment


                    #24
                    The change worked. It prints an asterisk every few minutes. I am at pass 10 so far. You're right, I was not waiting long enough, and I heard nothing of a bell so I had no idea whether the program was functioning correctly. At this point I am waiting to hear back from Ray who has my RL11 stuff, so I can resume testing the only thing that does not work - actually booting a disk.
                    @ BillDeg:
                    Web: vintagecomputer.net
                    Twitter: @billdeg
                    Youtube: @billdeg
                    Unauthorized Bio

                    Comment


                      #25
                      Hi All;

                      Bill, Good News !! Congratulations !!

                      What I would suggest and give a try at, is go thru the Rest of the Tests and Do the same Kind of thing, Change the 'Bell' to a 'Star' And see if any of them Fail or if they all Pass, That way You Know for sure, especially if You run all of the Tests..

                      THANK YOU Marty

                      Comment


                        #26
                        I spoke with QBUS by phone today, we were wondering what the minimum RAM requirement is for RT-11 v5. I may need add to the 16K I have installed.

                        Confirming one way or another about the RAM requirement might shed some light. At least in addition to any additional CPU tests.
                        @ BillDeg:
                        Web: vintagecomputer.net
                        Twitter: @billdeg
                        Youtube: @billdeg
                        Unauthorized Bio

                        Comment


                          #27
                          Hi All;

                          Good for You, Bill, If You have a MOS Ram Card of more Memory than Your 16K of Core, Throw it in there just for a Test, If that solves the problem, then You know that it is not enough RAM in the System.. And that will hopefully tell You How much Ram is needed, Core or otherwise..
                          If the problem still persists, then You know that You still need to look elsewhere..

                          THANK YOU Marty

                          Comment


                            #28
                            Originally posted by billdeg View Post
                            I spoke with QBUS by phone today, we were wondering what the minimum RAM requirement is for RT-11 v5. I may need add to the 16K I have installed.

                            Confirming one way or another about the RAM requirement might shed some light. At least in addition to any additional CPU tests.
                            From the RT11 v5.1 system release notes:

                            Capture.JPG

                            the RT11SJ monitor will run in 16KW, minimum. The documentation for v5.6 does not specify a minimum memory requirement (other than 28KW) that I can find, and for v5.6 the SJ monitor is renamed/redone as the SB monitor. So unclear at this point if v5.6 SB monitor can run in 16KW.

                            Earlier v4/v3/v2 RT11 systems could run the single job monitor in as little as 8KW I believe but v5 bumped the minimum to 16KW.

                            Probably the easiest test would be to configure a PDP-11 to the appropriate memory size in SIMH and trying to boot your test RT11 image.
                            Last edited by AK6DN; July 20, 2016, 04:40 PM.

                            Comment


                              #29
                              Found this:

                              "A minimal but complete system supporting a single real-time user could run on a single floppy disk and in 8K 16-bit words (16KB) of RAM, including user programs. This was facilitated by support for swapping and overlaying. To realize operation on such small memory system, the keyboard command user interface would be swapped out during the execution of a user's program and then swapped into memory upon program termination. The system supported a real-time clock, printing terminal, VT11 vector graphic unit, 16 channel 100 kHz A/D converter with 2 channel D/A, 9600 baud serial port, 16 bit bidirectional boards, etc."
                              @ BillDeg:
                              Web: vintagecomputer.net
                              Twitter: @billdeg
                              Youtube: @billdeg
                              Unauthorized Bio

                              Comment


                                #30
                                I have a 64K MOS RAM board installed in slot 3 of my DD11-CF backplane. Slot 3 is a MUD slot without the NPG jumper removed. The manual says it will work in any MUD slot. It seems to work OK. I ran a memory diagnostic and loaded BASIC.

                                On the same backplane slot 2 is a MUD slot with the NPG jumper removed. I have had the RL11 controller installed there. The RL11 manual says the M7762 should be installed in a MUD slot with the NPG removed.

                                I believe I have concluded correctly where to put the MOS and RL11 controllers and that they can be together. Any dissenting opinions?

                                If replacing the 16K core with the 64K MOS RAM will load RT11, I would conclude that one needs more than 16K installed in the system for version 5 all else being the same.

                                Bill
                                @ BillDeg:
                                Web: vintagecomputer.net
                                Twitter: @billdeg
                                Youtube: @billdeg
                                Unauthorized Bio

                                Comment

                                Working...
                                X