Beiträge von jlopez

    Das Typenschild lässt sich leider nicht mehr lesen. Es ist nur noch ganz schwach andeutungsweise was zu sehen.

    Ich habe vorhin mal kurz mit dem Oszi geschaut - scheint kein FBAS Signal rauszukommen.

    Aber das ist lösbar. Evtl. hat's ja nur ein paar der berühmten Tantal Kondensatoren zerlegt :)


    I don't think this is a problem related to capacitors. Were they the responsibles, the power supply would have a short and lock itself as a result, the computer wouldn't do anything at all. The good part is that you seem to have the damage located in the video card. Think about it... the system proceeds to load from the floppy after some keyboard interaction. CPU, keyboard and floppy cards must be fine. For testing, better remove the RAM card, the computer doesn't need it at all for minimal power-up.


    Regards,

    Jaume

    Greetings,


    I have a board from the arcade "Speed Up" (checked by its reference), from Spanish manufacturer Gaelco. The board seems to contain the EPROMs with the game and its graphics, as well seven custom ICs and what I think it is a Jamma connector (I am not entirely sure because I am not used to arcade hardware).


    20200612_164827.jpg


    The board was made in 1997 and seems to be in good shape but it is only part of the assembly and therefore the system is incomplete. Other than the cabinet what's missing is the board with the CPU (according to my sources, a 68k). Being that incomplete and missing hardware and experience related to arcades, it is offered as untested.


    The price I'm asking is estimated from the cost of some its components, which uncludes four 96-pin connectors: 35€. As the weight of the packaging is aprox. 558g, transport to any country from the EU would be done by the Spanish mail system Correos (13,20€ ordinary; 17,20€ certified).



    Summary

    Condition: apparently undamaged, untested

    Price: 35€

    Transport: Correos, 13,20€ (ordinary) / 17,20€ (certified); source (page 5).


    If there is any doubt, don't hesitate to ask.


    Regards,

    Jaume

    Which problems do you have with your P3? You have the 48K+16K RAM configuration in your P3?

    I can't recall if it started at all... at least a drive was running free and the other had an IC that seemed to be blown. But at this moment won't work for other reasons... Thanks for your interest.


    I think we should document the mechanism for bank switching with all the many P2 / P2 / P30 and sks KISS users.

    :thumbup:





    Or is the work too much?

    Cumbersome for a single person. Nevertheless, I could gradually post captures of exposed boards so nets could be generated. Having proper schematics is becoming a necessity for repairs...


    If you want, I could start a new thread on this subject as soon as the full board is exposed.


    Regards,

    Jaume

    Hello gpospi


    Definitely the memory wiring is different. I don't have the 64K configuration, but the 48+16 one. Months ago I found that both cards "talk" between each other using slot C. the 16KB board doesn't send the data bus values into the memories, they are receiving them from the 48K board and then are latched. There are lots of ICs in that board for only 16K... that must be the logic responsible for banking. I found another memory IC other than the '373, which is a '74 (d-type flip-flop). I traced its output to the connector (which feeds some gates before reaching its end). I suggest you to find such flip-flop in your 64K board.


    I'm glad you found the defective board. Thinking you had a defective CPU card, I started to disassemble CAAA08 last night. My P3 is also broken, even after a year... not because I couldn't but because convenience. Its unpopulated backplane is used for electrical tests for my own boards before connecting them into a working system (preventing wrecking the systems that work fine). The second reason is reverse engineering. Not long after receiving it I took care of documenting the backplane but the cards still remain to be documented.


    Regards,

    Jaume

    Hello,


    Toshi You found a nice one. ;)


    The case seems sturdy... seems far better than the one the P2 uses. Is that the case?

    I think I had never seen so many 2114 packed together so tightly. Implementing a memory of 48KB in size those days had to require three boards like this one... no wonder why they switched to dynamic ram. :/


    I know it's untested, but I remade the schematics for an EPROM reader I started a while ago. It uses the power supply from a standard P2 and its logic maps two zif sockets (one targetted at TMS2116 and the other at 1702A) and a standard 2716 (for the dumping routines) at the unused 5KB present in the lower 16KB of memory. I tried to maintain it as simple as possible. The idea is to test it this summer. I hope it could prove useful to you.


    P2 - EPROM Reader.pdf


    Regards

    Hello Toshi ,


    My effort is for dumping them only. While having the option to write is a good thing, it's not something I was seeking. My priority is to savage the data contained in the character ROMs, as they aren't accessible to the CPU and couldn't be saved with the RS232 trick.


    Thank you for those schematics. I'm sure they may prove useful.


    Hello helwie44 † ,


    For the special voltages, a regulator in case of the -5v (the easy way) and a resistor plus a zener for the -9V should do the trick.

    No, it wouldn't cause any trouble for an unexpanded P2, or an expanded P2 if it does not use the 64K mode.


    A circuit to burn them... that's beyond my skill. I don't see it to be feasible with the voltages supplied by the P2 PSU, especially the 1702A which requires 47V. Toshi 's options seem good to burn the EPROM.


    Regards Toshi  helwie44 †

    Hello helwie44 † ,


    This is a crude, unfinished prototype. Its schematics did not left the paper format, tomorrow I'll see if I still have them (I needed to clean my table as it was crowded with papers and notes). Meanwhile I signalled the different parts of the board and made a short description of its behaviour. It may also need a refinement and maybe even rework/patches.



    A: A couple of 70LS04. They invert the address bus from A0 to A10 (11 bits, 2KB address space).

    B: Decode logic. I used a 74LS08 to "cut" the 64KB range and selecting the lowest quarter. This selection signal is fed to the 74LS138, which divides the selected 16KB address range into 1KB chunks. The '08 is used again to "glue" two of the resulting signals from the '138 to form a 2KB range. The output signals from this block are the 16K selection to C, the 1K selection to D and the 2K selection signal to D.

    C: 74LS240. Inverts the output from the EPROMs and places the result into the data bus of the computer.

    D: Firmware ROM. This socket with the 2716 pinout is mapped at 0x1C00 - 1FFF (I told it wrong before, my apologies... that's what happens when giving memory too much confidence, especially when this was done in December or January). It should contain the software to read the EPROMs at D and prevent to reload the software manually every time the computer is turned off.

    E: TMS socket. This ZIF socket is wired with the TMS 2716 pinout. The only remaining signal to be connected to it is the -5V.


    The -5V generator circuit was not installed and while there are also lots of wires on the solder side, many connections still need to be made.


    The truth is that this board was in my scrap box. I abandoned the project when I had the prototype nearly built. I lost confidence on it due to its messy construction and the lack of proper test material. The only TMS2716 I have are those in my P2 units, none of them German. This means that in case of failure and destruction of the EPROM the data loss would be permanent... you know, there are no backups. A proper tester should have expendable ROMs filled with known content to test and dump the risky ones when reliability has been assured (unfortunately this is not the case).


    Some considerations if you are to build this. This board needs to be longer than the average P2 logic board; this is necessary if the ZIF is to be used, otherwise the board should be plugged and unplugged each time an EPROM is placed on it; this requires the system to have the upper case removed. I imagine that, being the reading process software controlled, it could be made compatible with the older TMS2708 without altering the hardware. For the 1702A, the simplest solution would be a second ZIF with a different pin arrangement and mapped at the same address space than the TMS socket and also the inclusion of the -9V line. As a reminder, this board has no logic to check if the memory bank is switched on as it was designed to work on my unexpanded 48K Italian unit; if this card is placed in a 64K system with its 16K board plugged there will be conflict in the data bus when reading the expansion memory.


    Regards,

    Jaume

    Hello helwie44 †


    If I understood correctly, are you seeking for an EPROM reader? I have one (mostly) built.



    That's my first 48KB and later 64K (failed) prototype which was recycled into something more useful. There are more wires on the solder side of the board... it lacks some connections between the '240 and the connector. It also still lacks the voltage divider/regulator from -12V to -5V. I imagine that for the 1702A to be interfaced an additional -9V line should be added.


    The target model is the TMS2716, no modern EPROM reader will read them without an adapter. The socket is mapped at 0x2000 - 0x2FFF and the ZIF is mapped at the unused 2KB RAM for the video system (I cannot remember it now) which is not used in unexpanded models. This way the driver shouldnt need to be loaded each time the computer is turned off-on (that's useful if you have lots of EPROMs to save).


    The way this board was designed was simplistic and thus it doesn't has bank control logic. It matters because it uses address ranges in the system page and in expanded systems it could cause trouble.


    If that's what you need, I could check if I have the schematics for this; but later today or tomorrow because today expires one of my deadlines.


    Regards,

    Jaume

    Gelegentlich mal zur Kenntnis nehmen, wie die Lage in Italien und Spanien ist, sollte den einen oder anderen wachrütteln.

    Daß die Leichen mit Militärlastern aus der Stadt gebracht werden, weil das sonst nicht zu bewältigen ist, gibt es sonst nur in Kriegsgebieten oder Hollywoodstreifen, die das US-Militär verherrlichen.

    Ob dieser Kelch an uns vorüber geht, ist noch längst nicht raus.

    *** Report from Andorra ***


    Infected: 224

    Healed: 3

    Deceased: 3


    The government is taking measures to protect foreign citizens with seasonal employment.


    *** Report from Spain ***


    Infected: 49844

    Healed: 9357

    Deceased: 4858


    The government has reacted too late, too little. It was not until a week ago that their president decided to create a comittee of scientists to help in the decisions.


    There's not anything related to the IQ of people... there are lots of smart people in Spain. The problem is culturally imposed: if Spain is known for anything is for its picaresque. If something is forbidden, then people will certainly do it; the "idiot" is the one who closelly follows the established conventions and then... the disaster happens. I still remember what happened at Totalán... that was pretty sad.


    Picaresque started to be important in society when the empire started to decline. The large amount of dissent, revolts and civil wars until the last century made it a desirable trait for common people to survive in those hostile environments.


    The following are some cases of the Spanish picaresque during this crisis:


    https://www.lavanguardia.com/v…allina-uga-lanzarote.html

    https://www.lavanguardia.com/s…saltar-confinamiento.html

    https://www.lavanguardia.com/s…bar-murcia-el-palmar.html

    https://www.lavanguardia.com/v…tado-de-alarma-salir.html


    People would do anything to get some fresh air. Some even react with violence when found by police or gc. In the (approximately) two weeks we've been enclosed I've seen lots of news like the four posted above.


    To close this post, the Darwin Award of the week... this guy (not Spanish) definitely deserves the award.

    https://www.lavanguardia.com/m…llenge-lamer-retrete.html


    Regards

    jlopez : Here in my region, the youth gathers at the evening at the playgrounds and other places drinking and having fun. For sure, school is closed like all recreation offers. So plenty of free time paired with lacking sense for responsibility. No accusation, 25 years earlier I would most likely have behaved likewise.

    I imagine so. :thumbup:


    But you know... that T-Rex and the dog-dressed-guy hurts the eye.


    Murcianic Park

    Walk time, Bobby!


    I hope if your young people doesn't care about their health, at least they do about their pride. People here in the South have shown no respect for neither of the two.

    Wie ist das in anderen Ländern?

    Both in Andorra and in Spain confinement was implemented last week. There are 50+ positives in my country with no casualties at this moment.


    Spain is, but the opposite. The government is scaling their measures to prevent people cheat the system. There were a few exceptions to the quarantine, one of them is walking the dog (just for hygienic purposes) or to go shopping. During those days I've seen things you wouldn't believe... things like:


    * People walking the dog all day

    * People walking a Guinea Pig

    * People walking a cat

    * People walking a goat

    * People walking a radiator

    * People renting their dogs

    * The skyrocketing number of dog walk services

    * Someone disguised as an inflatable T-Rex (Murcia, Spain)

    * Someone disguised as a dog (Escaldes Engordany, Andorra)

    * Confirmed cases of people who was infected (and knowing it) that travelled, sometimes in buses.


    The government measures came too late and while most people react as expected there are still a high number of people who seems allergic to follow instructions. It seems inevitable that the country will follow the Italian path... They have deployed police, Guardia Civil and also the army.


    I also have a friend in Milan who keeps me informed about how the whole thing is going there. Fortunately he seems to be fine.


    Regards,

    Jaume

    About the infection and mortality rate of Spain... It would be better for you to not extrapolate it with Germany. A lot of people reacted in an irresponsible manner to the warnings given by the local governments. Lots of them (mostly from Madrid) understood the quarantine as Holidays and travelled to coastal towns employing AVE, in effect crossing the country with it. Some of those people were infected. According to Murcia's president beaches and bars were full of Spaniards other than Murcians and decreeted the closure of any cultural site and cancellation of any event in order to discourage intranational tourism while the quarantine is enforced.

    Yesterday my government made two public statements. The first one contained early measures such as cancelling all school trips to outside the country or aadvising not to exit the country. It seems that after that the government met as a crisys cabinet and by evening they stated that a case of a 86-year old woman was confirmed, her daughter is a teacher and also was close to her. As a result schools close from Monday on. Other closures include the ski resorts, without them our economy will suffer greatly. The nearest supermarket is empty and I cannot expect the other ones to be different.


    It's official, that crowned virus has finally arrived at Andorra.

    Greetings


    As far as I know, the P1 had to be a cost-cut unit respect the P2 with 32KB RAM and a single floppy drive. According to helwie44 †, no P1 has been roaming around for years but the older P2 "white case" models are the most similar computer. There are differences between backplanes: the floppy drives received the power using the same connector as the data (it was slightly wider to accomodate the power lines) and also in the PSU and keyboard. The keyboard in the older models have different power/data lines, including a (minus? I can't remember) 9V and an EPROM instead of the 74LS154.


    Personally I don't have any of the older models so I don't know first hand. But maybe anybody who have it may be able to confirm it...


    Regards

    Char ROM was pulled from an (almost) working 8032 as unfortunately this computer came without its own. The replacement was known to be working. The VRAM was tested on that other board and found to be working too. Just as a curiosity, I recently found that they were made by Tesla, soviet-era Czechoslovak manufacturer; this means that the totality of its RAM ICs were from the Eastern Block.

    That site... Is one of the ones I found extremely useful.

    Yes, the division of Characters in dots was made in the 20s... this implies Hell was the inventor of the bitmap.

    Is curious how he stored the data. In those dark times when ROMs didn't exist he used a series of notched disks where the font was codified in binary.


    Did you know that the HellSchreiber pause character made its way into unicode? 0x2BFF.


    Regards

    Hamsterkauf means "hoarding" or

    "stockpiling". Of course, and that is the joke, it could also mean "buying a hamster" .

    But that is not the real point. Have you ever seen a hamster or a sqirrel collecting comestibles? It has large expandable chops. That is, where the german meaning of Hamsterkauf comes from.


    Stefan

    It seems today I've learnt a little more.


    Thank you, both to you and yalsi

    Having removed both PIAs (they were pulling /IRQ down) and replaced B2 (7425) and H1 (74LS74) I can proudly say that after 40 years the /RAS signal is pulsing again. I have but the side effect that the screen is not erased anymore. The two (and a half) lines are permanently on the screen. Doesn't seem to react on /RESET. Next step, fixing the video circuit maybe?


    Regards

    Ah, ok. What I don't understand by lecture is translated using automatic translator... apparently Google's AI loves hamsters. :)

    Yes, I imagine that the Spanish level is difficult to beat. A lot of "miraculous" remedies are flooding the social networks.

    WAIT! Do people really think that hamsters will protect them??!!??

    That's just crazy! Completely irrational! In Spain there's dumb people in social networks that say drinking baby pee cures Coronavirus...


    I didn't know that modern medicine has been supplanted by witchcraft-era remedies... A general state of panic is being created and when that hapens, people lose their mind.

    Two days ago the spare parts I couldn't buy at Barcelona arrived. I still have no /RAS and /CAS, but I least I found the cause of the CPU being stopped: /irq is permanently down. Today's first test will consist in testing VIA and PIAs, which are the only components that can cause this signal to go low.

    Yes I know the name was for this reason. But again, the situation was completely different from now. The belligerents had banned any kind of publication about the disease and in that case the ban helped propagating it. It seems that we humans like extreme scenarios: a case of complete lack of information vs infornography. We always fail to adopt a correct attitude agains those problems and it seems we never learn. And that brings the next point...


    No, the world isn't smaller. That's the price we pay for globalization. Events in the other side of the globe can affect us directly. In the past, cost of travelling was high and therefore people didn't used to move from their countries very often. Nowadays, the cost barrier has been smashed and as a result transit among far countries increased dramatically. Transmission of diseases and introduction of invasive species of animals are a couple of side effects we experience.

    calm down please.

    I am absolutely calm ... no prob. I just want to participate in this discussion with you & everyone. Everything's fine ... there are no worries. :)

    Ok. I had a different feeling when I read the first post... anyway, glad to know it. :)


    Medical staff are getting really worried, but because both mass media and politicians are causing unrest. This morning I heard an excerpt (I think it was fromRadio València) where they jokingly said that the only news that the Spanish tv media were broadcasting was from coronavirus and Catalan independentists. And this evening... yes, coronavirus and catalans. At least they aren't monothematic anymore.;)

    deleted_01_21, calm down please. Things aren't as dark as they paint it. Everybody seems to be overreacting about this issue. Coronavirus is not new, but an old enemy we know since the sixties. During those 50+ years there have been a few outbreaks but the total deathtoll of all of them is nothing serious compared with a single year's mortality of normal flu. Just as Toshi said, it's just that the flu is so common that nobody cares about it.


    About the Spanish flu, both events aren't comparable in any way. Our sanitation level is high enough to help to avoid infection (althought not 100% guaranteed). Back in the times of the Spanish Flu, Europe was putting end to a 5-year war. Maybe Germany wasn't in ruins but the ever-decreasing rationing was making its population to starve; soldiers on both sides weren't better: they couldn't maintain any kind of hygiene in the trenches. That was the perfect scenario for a pandemic. Fortunately this is not the case today.


    My advice: don't worry, it's not worth it.