Beiträge von jlopez

  • Repairing my CBM 3032 - Request for help

    Zitat von 6502

    Precision sockets are very OK.

    I think deleted_01_21 meant the original ones which quality was a common sore.

    I feel relieved now...

    Zitat von 6502

    The bad thing is that you need to understand the schematics and the chips data sheets to check every important component complex.

    There are probably good books on this.

    Optimum would be if you can find the service manual; it would give you an easy step-by-step guide to find the problem area.

    I'm working with a printed copy of it. That's where I found it -> http://www.zimmers.net/anonftp…ters/pet/2001N/index.html


    Zitat von 6502

    The monitor looks okay to me. I guess it is free-running (not synched), as it does not get a valid signal.

    The monitor is fine. It was tested and found working. Running unsynched? Good, that's really the kind of point I was seeking. The few characters displayed are seen correctly, I guess that this means that "Horz Drive" is ok and I should look for "Vert Drive". Suspects are, for now: G10 (74LS00) and H8 (74LS107); both of them in sheet 6. If found working then G8 (7474), G1 (74LS08), H5 (74LS00), I1 (74S04) and G2 (74LS20); all of them in sheet 7.


    For the testing, sync signals can be obtained at the user port easily.


    Zitat von 6502

    The dot after turning off is an old commodore flaw that provides for ugly burn-in holes in the screen middle.

    There are fixes for that available in the web.

    Yes, I know what it is and what it does. We call it "el punt verd de la mort" (the green dot of death) and I have other monitors that have this issue. What I didn't know is that there is a fix for them. I searched but cannot find the solution. Could you point me where could I find it, please?


    Many, many thanks.

  • Repairing my CBM 3032 - Request for help

    Zitat von Parser

    1. Have you already attached a display unit (monitor)? Any picture on the screen?


    2. As far as I can see, all of the RAM ICs are socketed, right? Did you check them one by one?


    BTW ... dual spring-contact for the IC-sockets would be much more better than the one's on your board ... they are not reliable and are often causing contact problems.

    1. Yes. I even uploaded the video at Youtube and linked it in the thread in the first post, but I link it again here -> (https://youtu.be/9vnJ7ftoyx4).

    2. Yes. Every U256 is socketed. In fact, I placed every socked on this board, even replaced the old ones -if the ICs were rusty, I couldn't expect the sockets to be better-.


    I was told just the contrary, that precision sockets were better. Does that mean that I must desolder every one of them and resolder again? :pinch:


    Thank you very much

  • Repairing my CBM 3032 - Request for help

    I have a scope, it's half-working but that should be enough. I'm using Zimmer's schematics for this board (he really did a good job gathering all that information).


    The 555 in the reset circuit has been replaced as was mostly eaten with rust. About the clock, my probe detected pulses at the output. But I guess I should check them. If they weren't the responsibles for the failure, wouldn't you know what should I look for?


    Thank you very much for your answer.

  • Repairing my CBM 3032 - Request for help

    Greetings,


    I'v been a couple of days working my CBM 3032 repairs. I started with this junk board:



    And left it in this state:



    There are a couple sockets more, but the output does not change. I have configured the jumpers as the technical manual states and replaced every EPROM with its original BASIC 2 from Commodore (NOS).



    The 6502 has been tested and is working, her only PIA has been replaced (missing pins) and the second one has been added. Some components like the '154 or the 555 have also been replaced because they were prey of rust.


    After testing a few times the result is this one.


    I'm also having no DOUT at the U256:



    And CAS fixed at high-level.



    I've tested some ICs regarding CAS and seem to be working... so I don't know what could be the issue.


    About the video circuit I'm sure there is a failure too, because those "junk" values should fill the screen completely but they do only occupy 2 1/2 lines in the middle of the screen.

    I am not sure about what should check now. There's no expertise in any system of the PET/CBM line in Spain as their sales were poor (and that's being generous). There are only a few of them, most in universities or in hands of speculators, some of them being offered for no less than 800€ or even in the range of 2k-3k€. For this reason I thought this is the best place to come for some help with this system.


    Just some background... This unit is nicknamed "The International" not without a good reason. Its case, PSU and monitor came from UK in a single block. Its BASIC 2, Kernal and Editor ROMs came from the same source. The keyboard came from Germany in a three units pack (all of them incomplete but I was able to build a working and complete one from pieces from the two 2001N, the other was one from a B model). The PIAs came from the UK too, but from a different source. After three years we found its board, which came from Italy but had memories manufactured at DDR. The character ROM was from the only Andorran PET, which is working but has some strange video problems. In other words it came from all around Europe.


    Regards,

    Jaume

  • Was hört ihr so für Musik?

    Wait! Are you really talking about vinyls?

    Therefore I accuse you of the terrible crime of being modern. :P


    Computers aren't my only interest... I really collect nearly everything classified as old. Music is not an exception. I own approximately 300 shellac disks, most of them at 78rpm, others at 80; most are standard but Pathé records are also present even if I'm unable to read them. Also there are berliners and 3 metal disks (a couple of them still have a side free to record). My turntable is about 50 years old, is portable and employs vacuum tubes. Would you like to see them?


    Some contemporary music I listen in less exotic formats are basically soundtracks by Ennio Morricone, Hans Zimmer, Jerry Goldsmith, John Williams, Danny Elfman, Basil Poledouris, Fujisawa Mamoru (aka Joe Hisaishi), Sakamoto Ryuichi and Kawai Kenji among others.

  • Mein neuestes Etwas

    Today I went to La Seu d'Urgell. Unfortunately the flea market is almost gone.


    I have visited l'Escrit (that office that was once pictured here in this thread) and its owner was amazed when I told him that his business was known in Germany. He told me that his son found pictures of their machines in a Japanese website.


    Even if the flea market has mostly disappeared, I found a place where I got some interesting items.


    A couple of NES games



    Three complete PSX games and the manual of Metal Gear Solid.


    And a complete 3DS game.


    In another place I found a calculator that I was searching for some time. It was my grandfather's but was damaged by dogs before I could see it. I have been fortunate to get an exact match but it cannot replace what's lost.

    On the left my grandfather's calculator, on the right the one found today.

  • Mein neuestes Etwas

    It's funny to know that they are known outside... but did they really called them so in the Deutsch translation? :shock:

    Just for the record:

    "Filemón" is a Spanish name, nothing special about it; isn't the most popular either but now even less due to the character.

    "Mortadelo" is not a real name. Is a forced masculine of "mortadela". This word has no direct translation to English but according to Google translator it should be "Wurst" in yours. So it bears a name of something similar to a sausage because he is tall an thin.:)

    It's sad when one finds that translators made only half the work and took a shortcut instead...::cry::

  • Mein neuestes Etwas

    Today, at the same site where I found the MSX-Basic beta videotape tutorial (I was searching for the missing part) I got the following items:


    #1: Nintendo promo VHS "Alto Riesgo", 1996



    Unfortunately, seems broken. Maybe with a donor VHS tape I could fix it.


    #2: Hard disk drive




    3 1/2" hard drive. The acquisition is so fresh that I still haven't got time to check its capacity, so I don't know how many megabytes it could store. Not very slim... very fat indeed.


    #3: Tebeo #126



    Tebeo was a Spanish comic magaziine, very popular during the 80s. It usually contained the stories those of the secret agents "Mortadelo" and "Filemón" and some other characters from other cartoonists. That magazine was so influential among the then young readers that comics are informally called "tebeos" in Spain. But the reason I took it was the last page of it.



    I found strange for a Spanish magazine about Spanish comics to came with publicity from a Japanese comic. Comics from Tebeo are very lighthearted while Akira is dark. Being 1989 in Spain I could have expected Doraemon or Dragon Ball being announced, but not a pivotal genre-defining Japanese cyberpunk work. So I found it curious and brought it home.

  • New memory boards for the P2

    After 3 months in transit and a complaint later my memories have arrived this same morning. They were expected to arrive a month and a half ago.


    I think that it is not necessary to say that once I received them rushed its construction...



    Then proceeded to its testing.




    FFEF -> 48KB recognized!


    That being said, I introduced a small error in the design of the board: about 1-1.5mm should be removed in order to place the bus connector. Otherwise everything is fine.



    Regards

  • Was ist DAS?!

    Zitat von escimo

    Definitiv kein TDC (Torpedo Daten-Computer) ;)

    You nailed it.:thumbup:

    When I first saw it I immediately checked some TDC models from different countries, but then I realized it was some kind of radio device.

  • Alphatronic P2 Netzteil Schaltpläne

    Zitat von gpospi

    Bei meinem P2-3A Rechner ist neulich das Original-Netzteil abgeraucht, d.h. die Netzfilter-Kondensatoren haben sich mit Knall und Gestank verabschiedet. Also stand auch hier eine Netzteilreparatur bzw. ein Tausch an. So wie bei den anderen Rechnern habe ich ein PC ATX Netzteil verbaut. Allerdings ergibt sich daraus bei dieser Maschine ein Problem, da nun die originale P1/P2-3A Tastatur nicht mehr funktioniert. Diese benötigt nämlich eine zusätzliche -9 Volt Versorgung, die ich aus dem PC Netzteil nicht heraus bekomme. Einen Versuch, ob die Tastatur auch -12 Volt verträgt wollte ich dann doch nicht riskieren. Also habe ich meine Ersatztastatur (samt Tastatur-Controller) aus meinem späteren "Bastel P2 Rechner" verbaut. Das Tastatur-Layout ist ohnehin wesentlich praktischer (z.B. sind die Cursor-Tasten alle am unteren Rand zu finden und nicht willkürlich über die Tastatur verteilt). Das System ist nun allerdings nicht mehr ganz original. Wenn ich mal Zeit habe, werde ich mich vielleicht doch näher mit dem Original-Netzteil bzw. der -9 Volt Versorgung auseinander setzen...


    Sad to hear about it passing... Mine was less spectacular but you should see how do Alphatronic PC's paper capacitors burn, that's the real show :). I saw that twice, the second time I even counted down as I knew what the outcome was going to be :D.

    The good news for you is that you could still use the ATX to generate the desired -9V by either using a 7909 linear voltage regulator or a resistor voltage divider on the -12V line. I'd bet for the regulator as it would be easier to install on the ATX adaptor (if you are using overCLK 's). I am confident you will be able to get it working in no time. :thumbup:


    Thank you for your findings. My father said (a long time ago) he would repair the PSU but unfortunately had to halt. Maybe with this he may find the failure.


    Regards,

    Jaume

  • Mein neuestes Etwas

    I found a Betamax tape.



    If really contains what the sticker says, it should be a MSX Basic videotutorial. Case and a second tape are missing; cannot test it because I don't own a beta player. However I guess this is better than nothing.

  • Sharp X68000 Compact

    Zitat von Tammy-Aachen

    Hier die Bilder!


    Alleine das Spiel ist sensationell!


    :sunny: Tammy

    What were you expecting? The Akumajou Dorakyura/Vampire Killer/Dorakyura Densetsu/Castlevania series was once the pinnacle of Konami's quality, both in graphics and sound.

    The X68k is a wonderful system. I would like to acquire one in the future. It is said that it sweeps the floor with the Amiga... however I cannot make the comparison by myself, as the only 16-bit computers at home are (excluding PCs) 2 A500 and a STe.


    Congratulations for your acquisition.:thumbup:

  • Mein neuestes Etwas

    It is a subjective matter.:nixwiss:

    In my case, my line for the PC is drawn at Pentium II (cpu <= Pentium II ? retro : just obsolete).


    However, it's up to you where you decide to draw the red line. I must admit that I haven't seen any computer from 20 years ago like this one you show. Any Pentium III I've seen came in a bulky metal cream-colored case. Sadly most PCs from then on seem all the same to me; if any unit is found its fate is just being scrapped for its PSU or expansion cards.


    I'd like to see in which side of the border you place it. Just curious.;)

  • Geschichte eines Alphatronic P2, der eine Reparatur (oder mehr) versucht.

    Hello,


    I will have a break of about two weeks. Since early November, everything came much faster...


    The card seems simple and straightforward. However I see a couple of problems here:


    * The disk is a Winchester. There was one at my university in Andorra. It was wider than a LP... I often joked about it being Enterprise's (from Star Trek) saucer section.

    * To use this modding the backplane is required. Not everybody may be willing to modify it. For instance, my collection is (mostly) shared and I have some restrictions. Maybe the Italian could be modded but the Spanish is literally "hands off".


    My two cents here may be adding extra logic to interface a CF as an inernal storage media. It's just an opinion, I haven't checked how difficult may be adapting SASI to this usage.


    Thank you for posting this. I have lots of old computers at home but P2 and PETs are my favourite by far, especially the former.

  • "Nintendo Playstation" Prototyp soll versteigert werden.

    Zitat von 1ST1

    Angeblich gab es bereits ein Angebot "im Millionenbereich" (ohne Währung zu nennen, im Falle von Zimbabwe-Dollar wär das nix), jedenfalls soll dieses einzig bekannte Exemplar der Nintendo Playstation nächsten Februar versteigert werden: https://www.golem.de/news/retr…-geplant-1912-145618.html

    It will end with an insanely high price. There are more fans of retro consoles than retro computers and the failure of this system to enter into production changed the whole videogame industry forever: it sank Sega and scuttled what was left of Atari and left only two of the three major players on nowaday's market.


    By still existing, it is a remainder of what could have happened. Does anybody imagine a SNES with CD-ROM? :D

  • Geschichte eines Alphatronic P2, der eine Reparatur (oder mehr) versucht.

    I've been (and still currently) busy with some university work. There are still five deadlines to meet between tomorrow and January 8th.

    Seeing no better option, 4164 are the way to go. Past Dec. 23rd (deadline #2) I'll work on it.


    Regards

  • Geschichte eines Alphatronic P2, der eine Reparatur (oder mehr) versucht.

    About the memory, I've been considering how to proceed with option #2. However it's too complex to develop. The GDP has simply not aged well, as it was made only with the 41xx family in mind. Using modern memories in the design is too complex and expensive to be considered viable. Still, there are two options.


    Third approach: following closely the datasheet

    Using 4116. I've been able to find sources of them, especially in PRC. Requires three different power lines.


    Fourth approach: following closely the example

    Using 4164. At this point, the cheapest of the viable options. Requires a single supply line.


    If someone has an idea about how to proceed in this case without using 35-40 years old memories, I'd like to hear about it.


    About MC80 bus interfacing and decode logic, 4 ICs, the switch and the resistors/resistor pack are required. This section could be built for around 3,63€ (estimate).

  • Geschichte eines Alphatronic P2, der eine Reparatur (oder mehr) versucht.

    When dealing with multiplexed memory addresses, latches are required to build the real "lineal" address. To recreate the 14-bit address two 8-bit latches are required, one would be updated by RAS and another one by CAS (these signals may require to be inverted). And that's the easy part.


    Then I realized the GDP outputs only a single bit and, even if the output of the memory is a byte it can set (or reset) a single bit of it. That's the real problem. Using long memories of 1-bit width was the original approach. If replaced by SRAM, extra work should be done.


    First approach: 32K x 8

    It would be cheap and fit the address space. Without a complicated logic it would rewrite all bits of a cell every time it writes or erases a pixel, corrupting the result. Even if made to work, it wouldn't be time-compliant.

    Not viable.


    Second approach: 16K x 8, Dual Port SRAM

    The memory ic may cost 5-6 times (at least) what a 32Kx8 or a 4116 would cost but still be cheaper than the 8x4116 assembly. It would neither require the three voltages. This solution would come configuring port A as read-only and B as a write-only, sending the output through a demultiplexer and the output of the latter to feed the SRAM input. I know, it seems confusing, a drawing should be easier to understand.

    Both address busses in the SRAM should be wired exactly the same so input port address corresponds to output port address. The demux is not a 74157 as it has both enable inputs tied together. So a different approach was taken.

    All 8 inputs of the decoder should be connected to two controlled buffers: one inverted and one non-inverted. This way every selected bit would be introduced in the data bus while the rest would simply flow through this section.


    Note that those are not schematics, just concepts, some thoughts. Those may be improved or corrected over time or, if a better solution is found, replaced. This is also made to consider both complexity and cost and if cost is deemed too high, the project may not proceed.


    Regards

  • Geschichte eines Alphatronic P2, der eine Reparatur (oder mehr) versucht.

    Zitat von gpospi

    Yes ok, this approach makes sense if we don't aim for full compatibility with the CRT 4A graphics board (as we anyway don't have the original software). Of course a new board using the same controller as the CRT 4A would be very close to the original board, probably just the MC80 interface (address mapping) would be different.


    Going a bit further the simplest solution would be to hook up a Raspberry with HDMI/BAS video output to the system (MC80 bus or even serial port) and define a graphics control language (to be sent from the P2 to the Raspberry, running a "display interpreter"). The "display interpreter" could basically do whatever we want, like emulating the EF9366 commands or run e.g. a "LOGO" interpreter (https://en.wikipedia.org/wiki/Turtle_graphics). A quick search led me to existing LOGO implementations for the Raspberry (http://raspberry-python.blogsp…logo-turtle-graphics.html, https://www.raspberrypi.org/forums/viewtopic.php?t=1290) and there are several examples available (e.g. <script src="https://gist.github.com/ramalho/ca3a355b3df471e29282.js"></script>). Piping serial input to the Xterm console on the Raspberry would not require any programming.


    Actually a similar approach (having a dedicated "video terminal device") is being used in the Philips P2000C: The main unit is a Z80-powered CP/M system which has an internal serial interface to a terminal board (based on a second Z80). The terminal can display graphics, output is controlled via Escape-Commands (similar to matrix printers' ESC/P language).

    Wait...


    In this case, it does seem (by ic count) they added nothong and they relied just on the GDP. A different approach doesn't necessarily mean incompatibility. Do you remember my first memory board? It was to the original board what day is to night; yet, it was the same thing to the computer. The only compatibility issues here may be introduced in the MC-80 interface but, being switch-configurable that is difficult to happen. Sometime ago, I read about unused ports (we need 11) and there's only one free 16-port range on the whole alphatronic series. As I don't recall the source mentioning CRT4, it could be plausible they used that same range. Then, the only incompatible thing would be software, but with the source at hand it can be fixed anytime if new information apears.


    This night I thought about a solution to the DRAM issue. Not an easy fix, but I think I found a solution. I don't have time now as I must leave but today I'll share it. It's not as cheap as I expected but if well-sourced it could still beat the 4116s in terms of cost. My doubts are if that is a valid solution, as I use components I have never used and don't know how would they behave exactly.


    Regards

  • Geschichte eines Alphatronic P2, der eine Reparatur (oder mehr) versucht.

    Zitat von gpospi

    This PDF I already know (in fact I just copied a scaled down version of it into my original post). Building the board should be feasible if we would have:

    • Picture of the wiring on both sides
    • List of components or at least a colour picture (to identify values of resistors).

    Without such info I doubt that it makes sense to start a project. At least my knowledge and time are for sure not enough to re-design a graphics controller just by looking at a black+white photo...


    I think there was also a graphics board for the PC8, maybe this can still be found somewhere. However I also had no luck with this so far.

    Hello gpospi!


    I think we need neither, as a 2019 design would use only the GPD as a vintage part. Everything else is secondary, depends on technology changes. Having no slot C implies no hidden requirements and by having dip switch it means it could be mapped wherever the user wants to. As it seems the GDP is the workhorse of this board and the other semiconductors are rather passive, the remaining things to do would be:

    • Interface the GDP with the MC-80 bus
    • Interface the GDP with its private RAM

    The example I found could be used as a basis for the rest of the circuit. It doesn't seem that TA did much more than that. The resistors near the switch expect them to be 4k7-10k, the top ones may be the ones of the oscillator.


    Regards

  • Geschichte eines Alphatronic P2, der eine Reparatur (oder mehr) versucht.

    Zitat von helwie44

    hello jaume,

    I mean it is set via a 4-bit switch dip (upper half-byte) the basisport address. It was as I see, was not the C-series of the mc 80 bus used.

    the connection side of the graphics card is not shown on the photo.

    Sounds good. That leaves less requirements to consider.

    I have some work to do... and a deadline in Tuesday, but I may give it a try during the weekend.


    Regards

  • Geschichte eines Alphatronic P2, der eine Reparatur (oder mehr) versucht.

    So it was not a third-party but TA...


    Yes, it has a low ic count. And anything that brings fresh air here is welcome.


    Assuming they aren't counterfeits (most come from PRC), EF 9366 seem to be available and inexpensive. Not considering 4116, but as my first boards some SRAM. If going the monochrome way it coud be sourced for about 11€, the colour way about 17€ (I'm not counting board or other ICs). Just some numbers. What ports did it use? Decoding a port is easy using a couple of 74138, but the wiring is important to be known. Does it uses slot C?


    Regards

  • Geschichte eines Alphatronic P2, der eine Reparatur (oder mehr) versucht.

    helwie44 †

    You mentioned some graphic extension card sometime ago, that used part of the unused memory range in the first 16K. While being third-party, I bet this one was mapped using unused ports (I think 8 ports in both 5xh and 7xh ranges were available).


    gpospi

    After taking a look to the datasheet, it seems to have a resolution of 512x256, noninterlaced.

    Bottom ic row seems decode logic (again, without docs is difficult to know how it's wired) and bus control signals translation (it was designed with 65xx/68xx CPUs in mind, without separate read and write signals), second-to top is RAM 4116 (x8) for a total of 16K. This memory is private and not accessible to the 8085. Top row may be glue logic, the GDP seems to multiplex memory address.


    I found an application example but with 4164.


    Thank you for posting it, always interesting to learn more about this system.

  • WARNING ! von HP verbaute SSDs haben Totalausfallcounter

    So, this seems not to be a case of programmed obsolescence? It then reminds me of Age of Empires (DS), it had a similar error that sometimes resulted in the destruction of the cartridge. But losing one of them is far more serious than breaking a game.

  • WARNING ! von HP verbaute SSDs haben Totalausfallcounter

    Zitat von Cartouce
    Zitat von jlopez

    The sole existence of such a counter is a shame for HP.


    "HPE wurde nach eigenen Angaben vom Hersteller der SSDs über den Fehler informiert ... "


    It seems that the SSD were not build by HP ...

    Maybe, but that's still a shameful practice. Due to technological limitations SSDs already have a limited lifespan, cutting it artificially is just pure evil. Data cannot be salvaged from dead SSDs (while possible from HDDs)... losing one is literally a catastrophic data loss.

  • WARNING ! von HP verbaute SSDs haben Totalausfallcounter

    The sole existence of such a counter is a shame for HP. How much time they do count is irrelevant, what really matters is that they make it fail on purpose. Their "only" error here is that someone set it with a lower value than usual and the whole scheme became exposed. Three years... about one year after warranty expires (in the EU, two in non-members). What will be next? One day after warranty expires? Those disrespectful industry tactics are also filling our planet with waste.


    I hope for some change in the industry standards but with the US and PRC... I don't know.

    One thing that I like of old computers is that they are (mostly) serviceable and some of them are running despite being 40-45 years old.

  • Mein neuestes Etwas

    Zitat von Jungsi

    Konsolen-Neuzugänge und Atari Merchandise :)

    Nice acquisitions! That GX... rare to find it boxed nowadays.


    If that's your first NEC TG-16, I recommend you to get an adapter to play PC-E HuCards (a large portion of titles for this system never left Japan). It is, however, nearly mandatory to acquire a CD-ROM2... Its best games are in that format. Do you have a NTSC TV or you'll mod it to output RGB?


    Regards