Posts by jlopez


    About two weeks ago I went to "Saló del Manga" in Barcelona and made some good findings. After my return I was very busy and that's why I didn't share this with you before...

    I got, as expected, Japanese content as books and movies. I got more, but only what I consider the most interesting of them are here:

    The golden age of the flying boat, by Miyazaki Hayao

    Movie theatre booklet of "Hotaru no haka", unopened since 1988

    Rupan sansei: Kariosutoro no shiro.

    This last one is very important. If, when young you played "Cliff Hanger", you actually watched fragments of this movie. It contains the prototype characters of some of Miyazaki's movies (it was his debut as director) such as Nausicaä, Fío, Muska, the Men in Black, Curtiss and apparently was used by the development teams of Konami during development of the original (pre Lords of Shadow) Castlevania/Akumajou dorakyura series.

    In the purely retro side, I found some interesting items from the three regions...

    Super Game Boy, the only European piece that I was able to acquire.

    This one was a surprise... It came apparently from the USA.

    Everything else came from Japan.

    Dorakyura Densetsu II

    Ghost in the Shell

    Ni no kuni

    This last one is very special because animation was done by Studio Ghibli ("Sen to Chihiro no kamikakushi", "Hotaru no haka", "Kurenai no buta", etc.). The composer is Joe Hisaishi, who has worked with Miyazaki since 1984. Being an special edition the box also contained a book which is the game's guide.


    The power supply is now feed through a custom connector from the backplane.

    After some checks it worked as expected. However, some seconds after mechanization of the custom connector, my dremmel-like tool started with an awful performance and then generated white smoke. I guess it is an ex-tool now.

    That's all for now. :):thumbup:


    I never experienced any of those issues. In my case, I just plugged the ATX PSU into the P2 or P3 backplane (with the simple adapter that I uploaded here already) and everything worked fine. In my P2 I connect the floppy drives directly to the floppy power connectors of the ATX PSU. In the P3 I keep the backplane wiring, i.e. the floppy power is provided via the original power cables leaving the backplane on the left side. Both approaches work flawlessly. I also never discharged anything and was not hit by electrical shock so far in the computers.

    I had to replace the connectors as I used an ATX 2.03 (P4). Every not used wire has been desoldered. Green has been curt short and soldered internally to GND so it awakens as soon it is connected to the power grid.

    While testing the adapter I had some trouble. R3 (labelled as a 390 ohm) is too small; killed the LED (D3). I replaced it with a 1k5 ohm resistor, also used in R2.

    I realized that the shutdown is indeed the short circuit protection system. So, something in my adapter is wrong and causes causes short circuit when connected to the backplane.

    I also found a way to discharge the PSU. I'll check if having grounded "green" is enough, otherwise it would need to be done manually.

    EDIT (3:08AM)

    Found the cause of the failure. Silly me. :wand:

    It's working now but will need the rearrangement of some parts. I will also mod the PSU again to legthen its inputs enough to pass them through the same overture as the outputs and feed itself from the backplane.

    Tomorrow, more tests.

    Regards and good luck!


    This afternoon I have modified my ATX to adapt it to overCLK 's board. I've built one of the boards too.

    When powered, without being connected to any backplane, it behaves as expected as all LEDs turn on. However when connected to the P3's one the LEDs flash, a short buzz is heard from the PSU and everything turns off. Being a PSU test it has no boards connected to prevent any possible damage. I guess that I've chosen wrong the +12v lines... I recall now that the floppy disk +12v lines must be isolated. Could this be the cause? I also need to discharge it to prevent shock... ATX use to be active for a long time after disconnection. Prior to the mod it was not powered for months (just for in case). Do you know a fast and secure way to do it?

    Thank you very much,


    There are guys in France which are programming graphical demos on Minitel. So it is not as useless as someone can think about.

    I asked on another forum for ideas, and someone came ta say that I coud use it as a terminal for a KIM. I don't have a KIM, but an AIM. Having some sort of screen for that computer sounds great.

    Yesterday I went to hunt at the market, in Les Glòries. It was a somewhat accidented trip and managed to get (late for my standards) into the market at 13h aprox. It was, however one of the finest market days I had in months.

    I picked a SNES. It has a defect in the bottom cover part, so I bargained a free PSP game. Later I got a NES with two controllers.

    I also was able to get one of MSX's most wanted: "Salamander". It was mixed with Megadrive and Genesis (yes, American) cartridges. Without negotiation, I accepted its modest 5€ price.

    Last, I found a terminal. I expected to find an Intersil 5027/5037/5057 but doesn't carry any those. I found it works (with some strange horizontal lines at the bottom part of the screen) so I decided to spare its life. I identified it as a Minitel and it's rare to find one here - they were common in France, but in Spain were more common the BBSes.

    That orange light is lovely, isn't it? Those tubes are very grateful when turned on after so much time. I noticed, however that it took an unusual long time to start. Strange. Even the beep was longer than next times I turned it on later.

    Just for info:

    The Roland CMU800 did use 2 PIT for tone-generation as well. The tones are seemingly generated at 2x the desired clock and then reduced by half (via flipflop) near the analog circuit of the individual tone. There is a rhythm generator in the schematic as well.


    Thank you very much! :)

    I didn't know Roland made a design based on the 8253. This one is a very complex design... Too much for me, but I saw they used an 8255. I considered using on of those too, but at the end didn't include it. Is curious that fact you said that tones are generated 2x and halved on the outputs. I don't understand why (I do on the clock input of the timer), but I'm sure they had their reasons. Another curious fact is that IC7 must be NEC-made... Is there any difference with other PITs?

    As you can see, I tried to improve the mood of the thread by including a humorous talk I had, but failed :wand:. I thought it could help but it was maybe a bad idea.



    Yes, it is. This web is not updated. Nearest ine is in Sant Feliu (I think). The one they closed was the nearest... and my only provider of Harting connectors. I'll need to order them from other sites (something I tried to avoid). In my country (Andorra) there's only one shop, and there's nearly nothing.


    Yesterday I bought most of the parts needed for building a pair of the prototypes. I failed to acquire most of the required resistor networks, and other crucial components such as FIFOs and memories for another project. Harting 96-pin could only get one, mainly because the only store where I could find it was liquidating stocks. Today has closed and won't open again... Onda Ràdio in Gran Via de les Corts Catalanes, rest in peace.

    This morning I had a strange talk about yesterday's purchase. It's messed and... bizarre. An excerpt is transcribed as follows:

    My mother: "Vas comprar molt ahir?"

    Me: "Sí, ho vaig trobar gairebé tot. Vaig comprar un kit. I ara a més tinc dos pits."

    My mother: "??"

    Me: "Si, dos pits"

    My mother: "Dos pits?"

    Me: "Sí, dos 8253 Programmable Interval Timer"

    I leave it untranslated, the confusion only happens when using my native language (Catalan). Google translator will mess it (correctly) for you :).

    In about a month, I will receive the batch. That gives some time to search for the missing parts.


    But the Joyce PCW looks quiet good...


    It's not a Joyce, but simply Amstrad:). In our zone they had not to rely on other companies to distribute their material. And yes, looks cool...

    It was here when I saw for the first time the Alphatronic logo... wonderful memories.

    Reflexion hides another machine. If I recall correctly is a Spectrum +. You deserve to see the full display, with its wooden frame... It's a curious image to see.

    It's strange that people in a German forum is discussing about a display in a town in the Pyrenees which lies "next door" to me. It's a weird, pleasant feeling.

    nicht mein neuestes Etwas - leider mit dem Flieger unterwegs ... gesehen in Spanien in Le Seu de Urgell ... cooler Laden 😆

    That's "L'Escrit". I know the owners personally. They made some donations to my collection.

    jefi You are far, far away from Germany... and very close to my location. Will you visit Andorra?

    EDIT: They don't have any 472 and do not sell their hardware. But display it in a fashionable way, isn't it?


    Your posts are the only helpful comments since I opened this thread and I thank you again for the information you handed to me. My experience consist as assisting repairs during 6 years, repairing computers and consoles by myself for the last two years. But conducting actual hw projects... I'm just starting. I'm a sw man. I've drawn a lot of schematics since I started university and got directly into a box. Some of my ideas are just exiting this limbo, others are just impulses. But in any case I'm limited by what I know (or more likeli, what I don't know).

    A couple of weeks ago I decided not to wire a board again. My hands tremble, but since mid-Summer it has worsened. It's difficult for me to do that. I also learnt from a failed experiment that debugging a point to point design ("spaghetti" is a more suitable term than design) is complex. And surprisingly I found it's cheaper to order crude prototypes than buying a stripboard. But, of course I'll assemble and test section per section and fix any error found. Starting with decode logic, then clock, then PIT...

    I'll try my design as is (mostly because there are five units in production just now). But I'll buy the parts you commented in order to try more than a single option. There is more than a single way to achieve the same thing. I'll consider seriously everything you say, as your experience is a valuable resource.

    About the clock, I expected this and got an aternative. I'm using a 3.579545MHz quartz in a typical not-gate square wave generator and frequency is halved using a flip-flop, therefore having a frequency of 1,789772 which is very close to that of the ALF. It "should" work.

    About long projects.. I know what it is. I've a CBM 3032 which needed some spares and was in the limbo for three years. :)

    Thank you very much,


    Thank you very much!

    The truth is that, when I saw there was an answer I was a bit scared. It could have been a second attack by angry Apple fans mad at me for I still don't know what reason.

    Thank you for your suggestions. I remain with the DAC0800 family but if I find it not working as expected I'll study again a quad-dac integration. I considered them but I didn't know how to solve conflicts in case more than one channel tried to write at the same time... But I'll consider them again after testing. I used a TDA2003 as amplifier. It should be enough for a 4 ohm speaker. And sure, I'll take a look at the PICSynth schematics. They look interesting.

    My expectations on those first prototypes are not high. I expect to have to patch them in a way or in another in order to make them work (that's a Russian roulette) or to improve their performance.

    Thank you again!

    It's been a long time...

    I've done a more exhaustive research and I've drawn parts not expected before into the project. It now doesn't follow the previously shown schematics. Its overall structure resembles that of a MC-16, but every channel behaves more like a Disney Sound Source, without its frequency limitations. I won't be able to wire it, so I ordered a 5-unit batch of prototypes. I don't know if something good will come from this, but for me it's worth to try.

    That's a preview of the front of my board. The only difference with the real boards is color, which is white.


    Thank you, gpospi .

    Yes, I remembered yesterday that you got it in a single card. Looks cool. I think you may be able to help me a little, we'll talk later in another thread.

    This night I also found that I was wrong about the memory cards being the same as in the P2. There is a slight difference I have realized this morning that allowed a major redesign in the computer.

    Today I will run its first test.


    On Friday I received this nice thing, courtesy of rfka01 .

    It was somewhat tricky to acces the inside parts but I managed to enter without breaking anything.

    Not much different from a P2 system.

    About those two...

    I'm a bit disappointed. I expected TA to build a 64K board and not having the same 48K+16K structure.

    This one took me for surprise. At first I thought that an EPROM was missing, but seems that the P3 has 4K ROM, isn't it?

    After a first check ( rfka01 told me that the unit is non-functional) I found an issue at the floppy controller board.

    That blue capacitor (C21) located near the FD1791B was dead and if I had turned the computer on I would have had a short circuit in the 12V line. I've also checked all four fuses and found no more failures. I replaced the capacitor about three hours ago. I'll clean and test it during this week.

    The keyboard... yeah... so heavy that it could be used as a melee weapon. It seems that was made to last long (and also for IT to kill their bosses too).

    But I am quite convinced that not everyone is posting his/her newest acquisitions.

    I imagine so... like when I got a 3032 with East german U256 memories...

    But for the large amount of material per person I guess:

    A) in Germany you have really high salaries


    B) the speculative bubble is still low there

    Here, this kind of stuff is starting to get prohibitive. And when referring to new publications (I'm not talking exclusively of videogames) we are subject to real discrimination when comparing with the other European regions.

    I am clueless...

    This thread is always full of new acquisitions (usually coming in generous numbers each time). And I was unable to find things other than overpriced trash the last time I went to the flea market. Seriously, I may be in the worst region of western Europe... I cannot find a better explanation to this phenomenon.

    By the way, nice captures!


    In the Spanish forums where I use to post another user posted about an adapter which allows the Panasonic KX-R194 to be used as a printer. Knowing that there, in Spain it may have no satisfactory answer I offered myself to ask here, as I know there's expertise not only in computers but also in typewriters and other good old electromechanical devices.

    Wouldn't anybody know about the foresaid module, with reference "KX-R60"? Is any document out there to check how it works?

    Thank you very much!


    There's an explanation to that. I know this model (I nearly had one, but escaped) and I have a 8032 + 64KB upgrade. As you said the model was cost reduced, in part because both boards were fused. There's no intermediate between 4116 and the 4164. If they wanted to make it with just the desired memory size, then the RAM IC count would have been 8 x 4164 and 16 x 4116 for a total of 24 ICs. Then, there are also the support logic in order to make it work, both banked and unbanked. You may expect a pretty high number of components just for memory and bank control. A second reason may be the control register. While there's an unused bit that could have been used to switch it, there is no free one to write-protect it. Changing this register format would have made this model compatibility with the 8096, which was the goal.


    I've updated the harting with Vcc and GND signals. The data bus has been declared this time as bi-directional (it was previously defined as output-only).

    I've reverse-engineered an important part of the 74's, although there's still a lot of work to do. Like in a subway, I've named the studied chunks as colors.











    I've named the ICs U1-U15. The vias found connected to the chunks have been named V1-V6. Parts of J3 have been defined. In labels, when the connection name contains "#" it is usually followed by a signal name or a pin number. If it is only a number, it is a reference to a pin, otherwise it is the signal name.


    Thank you again for the pictures. The first one will be very helpful. Unfortunately, when defining the connections from J3 to the main board I am of no help. I guess you need someone with better understanding of this computer than me for that part.




    The only reason for the 472 to exist was to deceive. Somewhere during early 80s a tax was introduced which affected computers with a RAM size <= 64KB. Amstrad took their 464 and removed the ROM, placing a socket where a daughterboard was connected. That little board contained the ROM and a 8KB SRAM (I think it was) and only the ROM was connected. If I recall correctly, it wasn't even connected to Vcc, so they were useless. In the manual they stated that the extra 8K memory was "not accessible to the processor because it was used by the ROM to excute the new functions". Yes, a ridicule excuse. That being said, when the tax was retired the 472 died with it and the 464 returned to the Spanish market (officially).




    Thank you for the new pictures. They have been useful. All ICs have been successfully identified now.

    I started to draw a proper schematic wiht KiCad, but the only thing "displayable" is the pinout of the Harting-64. At this point, it is still incomplete but at least it's cleaner.

    In my opinion, the contacts C (16, 18, 20, 22, 24, 26, 28, 30) may be the addresses A5-A12, but I won't be able to check it (continuity tests are required, as some tracks are under the ICs on the component side or under that blue socket on the solder side).

    I've signalled some labels and calculated the resistors' values. Those orange components seem resistor packs in a star configuration, but as I cannot see their reference it is just a guess.

    I've drawn the gates on the solder side to make it easier to draw the schematics. I hope that after flipping and flipping them I haven't drawn them wrong. The 74LS641 are bus transceivers. The bottom one seems wired to work as some kind of shift element.



    I've tracked a few tracks and identified some connections on the Harting.

    I still haven't checked connections within the 74's or the 2114s. ICs marked with an asterisk aren't confirmed (shadows, flash or not enough resolution for a successful identification). Some tracks from the top side are marked. Some Vcc and GND tracks are also identified, but this is not reflected on the image. Near the Harting there's a mark: "crt".