Beiträge von jlopez

  • Speicher 5150 5160 5155

    Zitat von orestecom
    Zitat von jlopez

    Is something wrong with your on-board ram?

    why mess around to find out, if you can just replace with an ISA. Could. Or event cannot

    Both Toast_r and lgp30 maybe right and wrong at the same time for this is Schrödinger's memory: only when you look at the schematics one or the other will be right.


    You see, if the memory is built directly in the data bus of the processor without buffering, then you can follow Toast_r 's advice. Otherwise, if there is a buffer, the point goes to lgp30.


    If the board is original, and without watching the schematics, considering it would be IBM I bet there is the buffer/transceiver. Only by examining the foresaid document you could determine if the component is completely unused after removing the ram. If that's the case, by retiring the buffers/transceivers you may have a chance. Otherwise you shall populate it before using the board.


    I hope it helps

  • Necromancing Datamasters

    Today I have tested my first rom patch for the two non-banked memories of the computer. With some tweakings it worked as expected and the computer started its testing as usual:


    Testing the patch


    With this simple patch many System/23 will be easier to repair and many will simply return back to life if they issue is only with memories 02h and 09h. A solution for the rest of the ROS memories is underway and should be ordered in the next batch, as well as a ram memory replacement/upgrade and corrected and improved of the parts which came in this batch.

  • HAPPY BIRTHDAY Amstrad CPC 464 :)

    Zitat von eto
    Zitat von jlopez

    I currently use about half a dozen CPCs to introduce teenagers to what previous generations used... they never expect the cassette to store information other than music. The monitors with integrated power supply are a solution for portability of the systems. The keyboard argument always takes place - they search where the "rest of the computer" is hidden.

    I was thinking about something similar but I never had the time to properly prepare it. I think the CPC is a great machine to teach the real fundamentals of how computers operate. The BASIC is quite good and powerful - and the results are immediately available including graphics and sound.

    It is comparable to a portable computer when having to move it thanks to the integration of power supply and monitor. They are simple and with only its gate array as Achilles heel. They are pretty sturdy.


    Users love to make sounds with the AY-3-8912 as it reminds to what traditional arcade games sound... unfortunately I don't have a quick way to introduce them to graphics, as the amount of data it requires makes it unfeasible for single sessions.

  • HAPPY BIRTHDAY Amstrad CPC 464 :)

    Zitat von MicrotronicHamburg
    Zitat von jlopez

    The keyboard argument always takes place - they search where the "rest of the computer" is hidden.

    40 (ok, 39) years later, and I still haven't found the ANY key! :stupid: :ätsch:

    I had the same argument with my father back when I was 13... I was told old computers were bigger in size and comparing a ZX81 with a then modern PC made me so confused that I called him a liar and left. Only much, much later I learned enough to understand and value these things. ;)

  • HAPPY BIRTHDAY Amstrad CPC 464 :)

    I currently use about half a dozen CPCs to introduce teenagers to what previous generations used... they never expect the cassette to store information other than music. The monitors with integrated power supply are a solution for portability of the systems. The keyboard argument always takes place - they search where the "rest of the computer" is hidden.

  • Necromancing Datamasters

    For today, I have a probe to test the system - it is a simple probe that displays the number of test the computer is performing. It is so simple that it only contains the leds and the driver ICs to control them. As the Datamaster only displays the diagnostics on the screen if certain prerequisites are met, this device is useful for black screen situations.


    https://youtu.be/UrLsx8ZtCpY


    By removing the memory board, I have found that the testing stops at the last failed test.

  • Necromancing Datamasters

    Good morning,


    I have ordered some prototypes for possible patches for this computer. Once tested, if they work as expected they would be able to recover broken units whose symptoms is just a black screen. For the time being, they would not work all the cases but only situations where RAM and ROM are involved.


    As detailed technical information has been lost, I am reverse-engineering it in order to document it. Some ports have been discovered, but most are still to be found.


    Regards,

    Jaume

  • Quelle für 4416 DRAMs

    Zitat von x1541

    früher habe ich die von alten Grafikkarten "gerettet".


    Heutzutage kann man die auch durch SRAM ersetzen, auf Adapterplatine. sieht halt nicht besonders schön aus, aber besser als gar kein Ersatz.

    Personally I prefer this approach regarding old memories whenever possible. In some cases it can also be used to upgrade the system. I am doing this with a Datamaster at this point because its memories are nowhere to be found and I am not especially fond of them.


    It is, however a bit more complicated than just placing the memory: a latch and potentially a negator is needed for the assembly work as expected. Still, In my opinion the work is worth the result.

  • IBM 6580 Displaywriter bootet nicht

    As of lately I have gained some experience regarding the Datamaster and I am trying to document it.


    When time comes to open it for maintenance, I would like to ask you if you could back up its firmware. As far as I see, the highmost cause for one to die is by rom failure. As fas as I know my romset is the only complete backup for Datamaster and updated versions would be welcome.


    I am trying to avoid the paperweight fate for this system and I am collaborating with some users of broken units to help them fix their computers. If that was your case, feel free to ask.

  • IBM 6580 Displaywriter bootet nicht

    Zitat von lgp30
    Zitat von pmut

    Floppy-Images habe ich nicht erstellt, jedoch gibt es hier einige Fotos der Disketten auf denen man sieht, was an Software überlebt hat.

    Ich weiß, ich bin auf der Suche nach Images auch auf deine Seite gestoßen. Beachtliches Konvolut! 8)

    Ich denke, es wäre zu Beginn am wichtigsten, die Originalsoftware bei Gelegenheit zu sichern, also z.B. die Customer Support Functions, und was es noch an IBM-Disketten gibt.

    Hello,


    No progress on the software side. Still, I am very curious about your system. Other than the disk software, is it functional?


    Regards,

    Jaume

  • Retro Chip Tester Pro vom 8Bit-Museum.de (vormals "SRAM/DRAM-Tester")

    Hello slabbi ,


    As promised, my list of CRC codes from my S/23, and some other devices I have dumped as of late.


    Item/labelReferenceCRC32Description
    Elektor Junior Monitor (+1k padding)27168F31BE42Lecture made from a heavily modified Elektor Junior Computer monitor which among other things had its TMS2708 replaced by a 2716
    RCCA v1.327256C7999065Lecture made from an unidentified Z80-based computer which seems to be an intelligent peripheral serial-controlled buble memory cartridge unit.
    S/23 PN8519412MOS 2364 pin compatible (CS LOW)73783bc7IBM System 23 Romset
    S/23 PN8519402b9569153
    S/23 PN85194044f631183
    S/23 PN851940348646293
    S/23 PN8519405bea5a812
    S/23 PN448118661c9866a
    S/23 PN849374707843020
    S/23 PN851941141e6c232
    S/23 PN8519407b17f5c6e
    S/23 PN851940804dcc52f
    S/23 PN85194149a3f70c7
    S/23 PN851940691b2969e
    S/23 PN85194160f9a99fa
    S/23 PN8519409
    		e451a5e2
    S/23 PN8519410b9fb8bf1
    S/23 PN851941722cb6de4
    S/23 PN44817112e665945


    Regards,

    Jaume

  • IBM 6580 Displaywriter bootet nicht

    Zitat von lgp30

    (sorry, dass ich diesen Thread wieder hervorhole ;) Wie ändert man denn das Subject bzw. erstellt aus der Antwort ein neues Thema?)


    Wir haben inzwischen auch einen Datamaster, die Standversion 5324, mit Drucker. Allerdings komplett ohne Unterlagen/Software.

    Hast du Images von deinen Disketten? Ich wäre sehr daran interessiert :)

    Hello,


    Sorry for answering an answer not directed to me and also for doing so in English.

    You can can find documents and images at bitsavers.

    I confirm they do apply too to the S/23.


    Regards,

    Jaume

  • Necromancing Datamasters

    Hello,


    I am currently studying the System/23. I would like to hear from users in this forums, especially but not limited to whoever had a broken unit and is waiting for a cure.

    In the current state of my study, I may be able to help raising some deadweights into working units.


    I would need you to report the current state of your systems, the fault they have (or had) and if you solved any previous nuance, what did you do to solve it.


    Regards,

    Jaume

  • Museum tips

    Zitat von detlef

    I did not do so much repairs in the last years and I do not have any YouTube subscribers that are asking for help. ;)

    But you did, and if you had to you would be able to do it again.

    I'm giving some tip/clue. How many are asking and how many do you have? I think you did not get it... read again, please ;)

  • Museum tips

    Zitat von detlef
    Zitat von jlopez

    Dear detlef, I see what you have done and sincerely I admire it. I wish I could collect the kind of things you collect and repair in the way you can do. For this very reason 1/13th of your current YouTube subscribers are asking you help with some creative, imaginative piece of advice... ;)

    I think you're confusing me with someone else. :grübel:

    Why do you think so?


    Regards

  • Museum tips

    Zitat von detlef

    I have no idea how things are in Andorra. How am I supposed to give any tips? :nixwiss:

    Hoho! 8o


    There are many, many aspects which could be discussed independently of the place. I am trying to find a sponsor, someone who understands why this matters and why it is needed. With a sponsorship I think I could get a place, nevertheless it is not the only way.


    Museums do exist in Andorra as well in other places of the world. What I haven't seen yet in my country is for a single person (or maybe 2) to push the whole project. At the same time, it seems they are so desperate they even executed some nonsensical initiatives such as a "Museum of water"... But it is like if they only listened to some certain people...


    The personal project is what matters. That's why am asking someone who have done it or is trying to, if could give me an insight. As small it could be, I shall appreciate it very much.


    Dear detlef, I see what you have done and sincerely I admire it. I wish I could collect the kind of things you collect and repair in the way you can do. For this very reason 1/13th of your current YouTube subscribers are asking you help with some creative, imaginative piece of advice... ;)


    Zitat von 1ST1

    Always when I pass by an empty large building somewhere the gearwheels in my head also start to turn... But who can afford this?

    I understand you. Many, many offices and buildings are empty. Some have been for many long years, but they prefer them to decay rather than lower prices (both to rent and to acquire). We are currently in the middle of a speculative bubble again. It seems people did not learnt from the 2007/2008 disaster. The minimum renting cost could expect for a very small flat is around >1200€/mo while minimum wage is around 1200€, prior to deducing taxes. Therefore the cost of rent is actually higher than minimum wage which is what most Andorrans actually perceive.


    Every time I pass by large number of empty, dusty offices, even in my very own street I get angry at the current state of things. I have even considered leaving to towns in Alt Urgell and while I had some interesting opportunities in November/December we lost them by mere hours and haven't been able to find anything similar. Who knows...


    Yes, that would be a solution, but in my case it is not applicable. I am not the only inhabitant at home. And this is one of the main reasons I am searching a proper place.


    Still, would you explain me a little how did your experience was, please? The truth is that I am very intrigued... :/

    Zitat von creopard

    I guess the best approach would be to contact someone, who already mastered this early stage successfully, like:

    https://www.homecomputermuseum.nl

    Sure, I will take a look and ask. Thank you! :good:


    Zitat von rfka01

    I can't remember the user names, but I thought there were private collections open to the public at least somewhere in Austria and the Upper Palatinate, so I encouraged jlopez to post here ... I'll try to find the user names I'm thinking about and connect them to this thread.


    Robert

    Last but not least, thank you. While I may have thought at it, I would not have dared to. :danke:


    Regards,

    Jaume

  • Museum tips

    Hello,


    I have as a long term objective to open my collection to public. Alas, I don't have the resources to do so. I need some piece of advice regarding acquisition of some space to repair/store/display it, as well as early stages of funding. Transporting and storing some of the systems and their documentation is also one of my worries. What could you recommend me?


    Regards

  • Retro Chip Tester Pro vom 8Bit-Museum.de (vormals "SRAM/DRAM-Tester")

    When I am done with its study, I don't see why I couldn't let it to you for a time. I would like to display it when you are done.

    But while I want to retain the piece, I am no longer interested in repairing it as component availability is about null. Yesterday, at the same time I was analyzing the board I was also designing a new one.


    PM me for your address, so when I finish I could send it.


    Thank you very much!

  • Retro Chip Tester Pro vom 8Bit-Museum.de (vormals "SRAM/DRAM-Tester")

    Zitat von slabbi

    Also the TMS4132 is organized 2x 16k x 1:


    It's one of the most regrettable things in the world that I could only thank a post a single time only. You deserves, at least 10k!

    Yesterday night found pins 4 and 5 tied together and pins 2 and 15 also connected. This is the component I was searching!


    Thank you a lot!!!


    The truth is that I am not that sure to repair it now, but I will document and prepare some adapter nevertheless. I found it with a short-circuit and I am thinking to fully replace it.


    Thank you very much!

    Jaume

  • Retro Chip Tester Pro vom 8Bit-Museum.de (vormals "SRAM/DRAM-Tester")

    Zitat von slabbi

    The 41128 can already be tested:


    These are 2 x 64k x 1 DRAMs.

    The integrated circuits at the board use multiple voltages (5, -5, 12) and continuity tests have proved they are all used by the dram ics. Personally, I don't know many other ram ic that use them all. Do you know if TI made something like that?


    EDIT: I expressed myself poorly. I meant if TI made some other dram ic over 16KB that had to be powered with more than a single voltage?


    Thank you very much

  • Retro Chip Tester Pro vom 8Bit-Museum.de (vormals "SRAM/DRAM-Tester")

    Zitat von slabbi
    Zitat von jlopez

    I have recently acquired a S/23 Datamaster. I would like to diagnose ram for faulty ics. For in case you don't know, in the DataMaster dram is built in daughterboards in a concept very similar to SIMMs and DIMMs, just larger and older. I don't know if your tester (which is excellent, I must say) already supports this feature, but in case it doesn't would you be interested in developing such extension?

    Do you have more information (data sheets) about these boards?

    Maybe this memory can be tested when a simple adapter is created.

    At this point I can only provide a couple of pinouts and some details/observations but I would provide more as I am studying and documenting them.


    You can find the pinout of those boards at IBM's own technical manual at bitsavers: http://www.bitsavers.org/pdf/i…_Service_Manual_Dec80.pdf

    IBM ofuscated the parts in this computer renaming all components with a custom code. DRAM memories are made by Texas Instruments and are encapsulated in PDIP-18 packages. They require +12V, +5V and -5V (4116??) and are structured in two banks of 9 (8 + parity). The board also contains two also ofuscated ICs which I think they are buffers and also some selectors.


    About the adapter: yes, this is what I would expect; to be able to test it with such a device. If you want, as I already have to document the board, I also could help you design the adapter. For obvious reasons I'd have also to be the beta-tester.


    There is, however some peculiarity with this board. When manufactured IBM soldered a second layer of dram memories in piggyback (I imagine they found it much more unreliable than they expected). Would this affect lectures with your tester?


    Thank you very much

  • Retro Chip Tester Pro vom 8Bit-Museum.de (vormals "SRAM/DRAM-Tester")

    Hallo Slabbi,


    I have recently acquired a S/23 Datamaster. I would like to diagnose ram for faulty ics. For in case you don't know, in the DataMaster dram is built in daughterboards in a concept very similar to SIMMs and DIMMs, just larger and older. I don't know if your tester (which is excellent, I must say) already supports this feature, but in case it doesn't would you be interested in developing such extension?


    Regards,

    Jaume