Announcement

Collapse

Forum 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.


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.


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.



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.


"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.

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

Help fixing my Olivetti M24 SP

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

    Help fixing my Olivetti M24 SP

    My M24 recently started to freeze with some garbage on the screen, also when idle-ing in the DOS-prompt.
    There are 512KB of memory soldered onto the motherboard and 128KB socketed. The socketed DIP16 ones were already replaced by me.
    However, I noticed that the issue persists as long as the M24 is warm/turned on. If i leave it turned off for a while, it boots as normal. If i reset it or cold boot while it is still warm, it results in garbage on the screen, no POST at all or a crippled "DMA CONTROL FAIL:04" error message.

    Could this be caused by the soldered memory? I don't want to solder if its not necessary. I've for sure tried to remove all ISA-Cards except for the graphics card, left it running only with the soldered memory, yet the issue persists.

    Idle-ing:

    Freeze:

    Reset (while being still warm):

    First own PC in 2003: AMD K6-2 500MHz, 320MB RAM, 40GB IBM HDD, 50x CD-ROM, 8x4x24 CD/RW, 100MBit LAN, 32MB ATi Rage 128 Pro, Windows XP

    #2
    Maybe unplug the graphics card, clean it's contacts and reseat it.

    And also consider, that a PC has not only system memory, but also video card memory.

    Please run also the M24 customer test, alternatively also Checkit 3.0 mainboard tests.
    <album>

    Comment


      #3
      Within the last days I did the following:
      - Removing the graphics card and cleaning the contacts with a contact cleaner.
      - The memory configuration jumpers were incorrect. I have 512KB in BANK0 and 128KB (socketed) in BANK1. The jumpers were set for the other way around, resulting in a warning of customer test. (DIP0, SW1-4 and SW8 BANK1 enabled). However, this was the case for the last 30 years now, so its imo not the root cause.
      - In the end, customer memory test passed without errors. Same for CheckIt 3.0.
      - I've got a Monotech MicroRAM yesterday which allows me to enhance (if needed) base RAM and use UMB areas. I've configured my M24 to 128KB BANK0 RAM (despite of having 512KB soldered on it) and 0KB in BANK0 and configured the Monotech card to fill up the space from 128-640KB.
      - Reseated all DIPs of BANK1 into their sockets after cleaning them with a contact cleaner (not using the Monotech card at all).
      - Replaced the DIPs in BANK1 with 256kx1bit DIPs I took from a 286 (not using the Monotech card at all).
      - I've found this post here:
      http://www.vcfed.org/forum/showthrea...927#post559927
      Originally posted by Trixter View Post
      According to ftp://ftp.oldskool.org/pub/drivers/A...%20listing.pdf it is a failure found while testing the DMA chip in the first 64K. So yes, you have a bad chip in the first 64K. As for piggybacking, I haven't had good success with that, but I haven't had a lot of success troubleshooting drams anyway, so it couldn't hurt to try. You can also try the finger test, to see if one of the chips is substantially hotter than the others.
      - Thus I've tried piggbacking all of the 18 soldered chips with 256kx1bit DIPs I took from a 286 while having BANK1 empty and disabled (not using the Monotech card at all), one by one, with no outcome.

      All of the above didnt fix the issue. Currently the M24 POSTs correctly in any case but locks up randomly while booting to DOS or using mTCP apps. A freeze is permanently reproducible when starting CLOCK.EXE in Win2.11 and 3.0 under PC-DOS 5.0 - the mouse pointer can be still moved around for another minute, but Windows and the keyboard is locked up, except for CTRL+ALT+DEL. On the other hand I can start as many other applications, including CONTROL.EXE, until RAM is full. Since this is strange, I already disabled the RTC via jumper, but no change. If I boot from MS-DOS 4.01 floppy and start Win from there, also CLOCK.EXE works. Maybe this is some weird IBM-DOS compatibility issue and the initial problem is resolved. Today I will try again to switch to MS-DOS 5.0 which previously already locked up while booting from Setup Disk 1 in 10 out of 10 attempts (which is why I used IBM DOS 5 instead, to enable me access to UMB area for the Monotech card). Fingers crossed.

      Which chips in BANK0 are the first 64K? Since I do not trust in piggyback that much and due to the DMA:04 error, I assume I have to desolder 4 chips, but I do not know which ones:
      https://hosting.photobucket.com/albu...d/IMG_1830.jpg
      https://stason.org/TULARC/pc/motherb...24-M24SP-1.png
      Last edited by freakedenough; October 7, 2020, 11:15 PM.

      First own PC in 2003: AMD K6-2 500MHz, 320MB RAM, 40GB IBM HDD, 50x CD-ROM, 8x4x24 CD/RW, 100MBit LAN, 32MB ATi Rage 128 Pro, Windows XP

      Comment


        #4
        Try to get Olivetti or AT&T branded MS-DOS. Originally these machines were delivered with MS-DOS 3.20/3.30, maybe that fixes your issues. I only could provide you german versions of 3.30 and 5.0 olivetti branded. (and they are on 1.44mb image)

        Or try original Microsoft branded.
        <album>

        Comment


          #5
          If you have a German Olivetti branded MS-DOS 5.0 I would be happy if you could share it with me. I have 3.20 on my own, but it lacks support for the 1GB XTIDE partition.

          First own PC in 2003: AMD K6-2 500MHz, 320MB RAM, 40GB IBM HDD, 50x CD-ROM, 8x4x24 CD/RW, 100MBit LAN, 32MB ATi Rage 128 Pro, Windows XP

          Comment


            #6
            The fact that your issue doesn't happen when the system is cold, but then starts to happen as it warms up, suggests either faulty components or bad solder joints. It might be helpful to reflow the solder joints for at least the DRAM chips.

            I've configured my M24 to 128KB BANK0 RAM (despite of having 512KB soldered on it) and 0KB in BANK0 and configured the Monotech card to fill up the space from 128-640KB.
            I don't think that will work? Won't the physically soldered 512K RAM be the RAM that responds to the address lines?
            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)

            Comment


              #7
              Originally posted by Trixter View Post
              I don't think that will work? Won't the physically soldered 512K RAM be the RAM that responds to the address lines?
              At least it counted only up to 128K

              First own PC in 2003: AMD K6-2 500MHz, 320MB RAM, 40GB IBM HDD, 50x CD-ROM, 8x4x24 CD/RW, 100MBit LAN, 32MB ATi Rage 128 Pro, Windows XP

              Comment


                #8
                I could install MS-DOS 5, but I had to remove autoexec.bat and config.sys from the setup disk, to avoid loading "nlsfunc" and "keyb gr", otherwise it locks up. But OK, I know that the M24 keyboard is very specific.
                However, in the end I got this error when trying to run CLOCK.EXE on the first attempt. Afterwards it remained unchanged to PC-DOS - it just freezes, but I can still move the mouse pointer.

                All other stock apps like Write work...
                Crazy, isn't it?

                Which are the first 64KB of RAM on the M24? Which 4 chips in Bank 0?

                First own PC in 2003: AMD K6-2 500MHz, 320MB RAM, 40GB IBM HDD, 50x CD-ROM, 8x4x24 CD/RW, 100MBit LAN, 32MB ATi Rage 128 Pro, Windows XP

                Comment


                  #9
                  OK that's weird. I kept the PC running while I typed the above post, and the clock appeared after 4-5 minutes, but it was not ticking. Menu of the clock app (about screen) worked, also minimizing to an icon.


                  Is there maybe some other issue than with the RAM? CPU?

                  Edit: now it locked up completely.

                  First own PC in 2003: AMD K6-2 500MHz, 320MB RAM, 40GB IBM HDD, 50x CD-ROM, 8x4x24 CD/RW, 100MBit LAN, 32MB ATi Rage 128 Pro, Windows XP

                  Comment


                    #10
                    Okay, found the cause for this. I tried once again to remove all device drivers one by one, and after removing CLOCK402.SYS the issue was resolved.
                    I believe the inital issue with a freeze and garbled screen got resolved by playing around with the jumpers, resocketing the DIPs and using contact cleaner.
                    Oh man, I should have read the readme of this driver way earlier, it would have saved me a lot of time.
                    *** DISCLAIMER *** The SOFTWARE clock driver may not work correctly with
                    unsupported PC6300 DOS Versions, such as DOS 5.0 or higher, or non-AT&T DOS
                    versions. SOFTWARE applications which load into a memory range that conflicts
                    with the SOFTWARE clock driver may cause unpredictable results. Any SOFTWARE
                    applications which continue to read the HARDWARE clock instead of the DOS
                    clock WILL continue to see the wrong date.
                    Still i would love to know which DIPs of BANK0 are "the first 64KB of RAM". And does anybody know if there is an alternative to CLOCK402.SYS?
                    Last edited by freakedenough; October 8, 2020, 11:53 AM.

                    First own PC in 2003: AMD K6-2 500MHz, 320MB RAM, 40GB IBM HDD, 50x CD-ROM, 8x4x24 CD/RW, 100MBit LAN, 32MB ATi Rage 128 Pro, Windows XP

                    Comment


                      #11
                      That's something I can confirm. "keyb gr" from Olivetti DOS 5 hangs on M24. I use "keybgr" from Olivetti DOS 3.30 on DOS 5 and it's fine.
                      <album>

                      Comment


                        #12
                        It just freezed again while idleing in the DOS prompt, but the cursor is still blinking. No reaction on CTRL+ALT+DEL.
                        It drives me crazy...is there something wrong with my config maybe?



                        Code:
                        DOS=UMB,HIGH
                        DEVICE=C:\DOS\USEUMBS.SYS A000-B000 C000-D000 E000-F000
                        DEVICE=c:\dos\DOSMAX.EXE /R+ /N+ /P-
                        SHELL=c:\dos\SHELLMAX.COM C:\DOS\COMMAND.COM C:\DOS /E:512 /P
                        FILES=40
                        BUFFERS=30
                        BREAK=ON
                        DRIVPARM=/D:0 /F:2
                        ;DEVICEHIGH=C:\DOS\CLOCK402.SYS 2020
                        DEVICEHIGH=C:\DOS\ANSI.SYS
                        DEVICEHIGH=C:\DOS\SETVER.EXE
                        ;DEVICE=C:\DOS\PALMZIP.SYS
                        Code:
                        @echo off
                        rem LH C:\DOS\NE2000.COM 0x60 0x4 0x360
                        LH C:\DOS\MOUSE\MOUSE.COM
                        LH C:\DOS\SHARE.EXE/f:4096
                        LH C:\DOS\wd8003e.com -w 0x60 0x03 0x280 0xD000
                        set mtcpcfg=c:\mtcp\sample.cfg
                        PATH=C:\DOS;C:\WIN211;C:\WIN30
                        set TEMP=C:\WIN30\TEMP
                        C:\DOS\mode.com co80
                        PROMPT $p$g
                        cls
                        Last edited by freakedenough; October 8, 2020, 01:29 PM.

                        First own PC in 2003: AMD K6-2 500MHz, 320MB RAM, 40GB IBM HDD, 50x CD-ROM, 8x4x24 CD/RW, 100MBit LAN, 32MB ATi Rage 128 Pro, Windows XP

                        Comment


                          #13
                          Originally posted by freakedenough View Post
                          It drives me crazy...is there something wrong with my config maybe?
                          If it works on a cold boot, but stops working the longer you leave the system on, then my guess is a hardware/component failure.

                          You might be able to isolate which component by doing basic troubleshooting: Remove everything except the floppy drive, hard drive, and video, and you should boot Olivetti DOS 3.x with a clean/empty CONFIG.SYS and AUTOEXEC.BAT, and do your testing with that. If it still locks up, you have hardware issues on the motherboard that you'll need to start troubleshooting. If it works fine for over an hour, start adding hardware and config.sys/autoexec.bat entries back ONE AT A TIME and test extensively, and maybe you'll find something interesting that can narrow things down.
                          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)

                          Comment


                            #14
                            I've done that already for sure, it didn't help.
                            Today I bought 18 DIP16 sockets and did the crazy 576 solder joints work and removed the old RAM, installed the sockets and new chips. I hope it was worth the 3hrs of work. With the first set of new chips (100ns -10 instead of 120ns -12) it didn't POST at all. I was already afraid that I killed it...


                            Right now its up for 20 minutes without a freeze. Longer than previousely.
                            Last edited by freakedenough; October 9, 2020, 10:45 AM.

                            First own PC in 2003: AMD K6-2 500MHz, 320MB RAM, 40GB IBM HDD, 50x CD-ROM, 8x4x24 CD/RW, 100MBit LAN, 32MB ATi Rage 128 Pro, Windows XP

                            Comment


                              #15
                              Seems to work now. It is running since 54 minutes without freezing.
                              Last edited by freakedenough; October 9, 2020, 12:33 PM.

                              First own PC in 2003: AMD K6-2 500MHz, 320MB RAM, 40GB IBM HDD, 50x CD-ROM, 8x4x24 CD/RW, 100MBit LAN, 32MB ATi Rage 128 Pro, Windows XP

                              Comment

                              Working...
                              X