Posts by jlopez

Quote from klaly

Hi, jlopez,

here is the Alias kkaempf (Klaus Kaempf)

But the problem is, The documents are no longer with him, they are already in Raffzahn (Hans Franke's) "warehouse".

So he can not correct the possible mistake.

best regards

Klaus Loy

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Well, don't worry. I could play with what I had and made a rearrangement of the pages from both files. I think they are correct now, but without the paperback source I can't guarantee either if any page is missing or the order is maintained.

Thank you very much

P.S. I append the ammended files. I hope they are useful.

Quote from klaly

Die Scan Arbeit wurde nicht von mir, sondern von Klaus Kämpf (auch hier im Forum) durchgeführt. Ich war lediglich beim Transport beteiligt.

mfg. Klaus Lo,

Hello klaly,

I have examined the documents... I'm not sure but in my opinion there has been something wrong during the scanning of the CPU cards' manuals.

* CAAA02 has 22 pages while CAAA06 has 11

* CAAA06 has pages 1-4 (3-6 in the pdf) repeated at the end of the document

* CAAA06 contains only a schematics page (USART)

* CAAA02 contains 8 pages with schematics, including those of CAAA06

* CAAA02 has page 1 (page 13 at the pdf) duplicated at page 14 of the document

My guess is that both documents got mixed. I don't know Mr. Kämpf's alias so I cannot ask him if a revision of those documents could be done. Could you get in touch with him, please?

Thank you and regards,

Jaume

Thank you netmercer  klaly  horniger  Holger  jobi23  Raffzahn for your involvement in taking care of this knowledge. For years we could only rely in helwie44 documents and a few scraps we have been able to obtain by other users' findings and reverse engineering. If I could ask you make it public when the work is done I would be very grateful.

Also thank you helwie44 for getting in touch, otherwise I would have missed the documents for sure.

Now that the communication between expanded memory and CPU is clear, I might be able to end my memory expansion. What I could not find is when do the video card discern whether the bank is activated or not.

Quote from gpospi

Cool! Damit ist aber auch klar, dass ich mit meiner "Standard CPU Karte" und 16 KB SRAM Karte keinen Erfolg haben werde.

Ist ja insgesamt kein Problem, ich habe ohnehin noch zwei P3 mit 64 KB (und diverse PCs mit 4 bzw. 8 GB)

Well, now that many technical manuals are known not to be lost you may have a chance. What backplane and CPU card do you have?

Quote from overCLK

Very nice jlopez. I was able to superimpose both sides with layers on Gimp and now following a trace is a piece of cake.

I just need to go enabling the proper side of the board when I reach a via, what is very time consuming and sometimes quite tricky with just the populated board:

Thanks a lot.

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No need to thank. In reality, I should thank you. I tried to map it two or three times, but my head is not where it should be. At least for me its a relief you find it useful. You may need the component layout too to trace it correctly, tomorrow I'll scan it.

Quote from helwie44

My local clon GIT and a test here:

So far I have to upload my local changes to the GIT system.

I have both file explorers a) local on the DESKTOP and b) logged in GIT with

your RetroAND /SKS Alphatronic DS archives in the EXPLORER.

but how does it continue?

(maybe my changes could end up wrong somewhere?)

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Don't worry. Tomorrow I'll prepare some crash course for you.

First, you need to clone the repo. This means creating a local copy of it into your computer.

The easiest way is by selecting "Code>Open With gitHub Desktop"

Then a folder structure will be created on your hard drive. Github Desktop will take account of the changes you make and, when you are sure the contributions you made are fine enough then using GitHub Desktop you shall proceed to commit and push.

Summary is mandatory, description is recommendable. After that you may see push on that same screen; that would add the changes into the repository.

Regards

Repository created.

SKS-Alphatronic-DS Archive

It actually contains some of the datasheets related to the main ICs of the computer, the Spanish Char ROM and the scans for CAAA08. I suppose I could add more data yet today it's not the best to dig into my hard drive. Still, it is accessible for in case anybody wants to add/modify anything.

Best regards

Quote from overCLK

Hello helwie44, jlopez

I'm also for a git repository so that anyone interested can have access to it. Maybe it makes sense to have one and upload there all the related information we have/create?

What do you think?

Best regards

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If structured correctly we could store all related datasheets, lists of compatible references for the main ICs, manuals, system ROMs, schematics (with US logic nomenclature), kicad symbols and footprints for obsolete parts.

Quote from helwie44

Quote from jlopez

Returning to more practical matters, I could post the scans here or alternatively I could upload them to a new git repository so anybody interested could work on it. What do you prefer?

YES jlopez , your comments are exactly my opinion. We should invent a new THREAD to decipher some basics - for all users.

At that time I had developed some software emulations in the GIT system with rfka01, such as the ITT3030, alphaTronic P30, P3, P2U, P1.

The equipment was provided by a large number of developers. But I had mostly sent a lot of internal technical information via rfka01 and he built this data into the GIT.

Would a GIT project then be a hardware problem?

Greetings @ hellwie44

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Well, by small I meant we aren't like the Commodore or Spectrum user groups and as such we must rely more on ourselves.

I suggested GIT because it provides a high degree of reliability regarding the members and how they manage the project. In case of the foresaid board, I retraced around half the tracks but every time I tried to continue I lost focus and had to stop. While github is mostly software-oriented, there are also hardware projects dwelling around.

Quote from helwie44

Hello overCLK, jlopez;

Ok, but I have very little experience with the GIT system.

I would then possibly always send information and my technical data to one of you by e-mail. That would also be a certain preliminary search to see whether that would be expedient in the GIT.

Would that be okay ?

helwie44

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Don't worry about that. I could teach you how to do it, but only if you are ok whith it

Quote from overCLK

I was wondering if it's possible to change the banking from MOS with some command. Checked the manual but was not able to figure out if it's possible to send an OUT to the CPU to modify the banking mode. Do you know if this is possible?

It's a pity that the schematics are no longer available.

It would be out 0x78, 0x20 // out 0x78,0x60; you could trigger it using the system hex monitor. However, if the test program is not well-written you may lose MOS control and become stuck in the extended bank until reset.

Yeah, that's sad; but let's not cry over spilled milk, do we? After all it is how war is, and time is an unforgiving enemy. Fortunately, even if we (P2/P3 users) are a small community inside this generation of computers' curators we may succed in preserveng them with the help of one or another. Fortunately helwie44 has been able to save most of the software related documents, so the soul of the system is mostly safe.

Returning to more practical matters, I could post the scans here or alternatively I could upload them to a new git repository so anybody interested could work on it. What do you prefer?

Greetings

Quote from overCLK

- There is a connection in the backplane between the 48K and the 16K boards. My theory is that it allows to disable PCS from the 16K card. This makes probably sense because the output buffers of the 16K board are always active (the 74LS240 has the output enable line to GND) and therefore there must be a way to avoid both output buffers in both cards to be enabled at once. This is performed by the backplane connection on pin 75 or at least this is what I have observed in my setup.

I found the scan of the paper I made long ago regarding CAAC08. Sorry, it's not the cleanest but I hope it gives some insight of how this works.

In case you need schematics for the CPU board, I don't have them but I have the next best thing: the scans of the bare, unpopulated board on which to perform the reverse-engineering process. Reference is CAAA08 (P3) so there may be some differences such as a single 4k ROM, etc.

overCLK : Could you monitor the states of both /RD and /WR at the same time while testing?

According to the docs, /PCS is used to inform the controller that a request was made, initiating the proper cycle. Assuming /PCS is low, cases are as follows:

If you monitor both control signals directly on its corresponding pins of the DRAM controller and found them stuck at a wrong state it would trigger a test cycle instead of a read/write one. If that was the case, you would only need to trace the signals back into the backplane and check what components modify their state.

By the way...

My Italian card is not the same as neither yours or helwie44, but my P3 DRAM board is CAAC09 which has connections in the 3rd slot. Both wear a 8202A.

I could test with mine if you want.

Regards

I took a look into the 8203 datasheet and found this interesting excerp:

Quote from 8203 datasheet, section 2-3

16k/64 Option Selection

Pin 35 is a strap input that controls the two 8203 modes. Figure 4 shows the four pins that are multiplexed. In 16k mode (pin 35 tied to Vcc or left open), the 8203 has two Bank Select inputs to select one of four #RAS outputs. In this mode, the 8203 is exactly compatible with the Intel 8202A Dynamic RAM Controller. In 64K mode (pin 35 tied to GND), there is only one bank select input (pin 26) to select the two #RAS outputs. More than two banks of 64K dynamic RAMs can be used with external logic.

In other words, if pin 35 is not grounded it should behave as a 8202. So, it's the same as with the video card using 5027 or 5037.

Maybe they got short of 8202 and started using the then new 8203. I'm going to check what the Italian had installed.

Quote from netmercer

Meine Karte ist mit 8 x Mitsubishi M5K 4164 NP-20, also 64K dyn. RAM bestückt. Der Speichercontroller ist ein Intel D8203 und kein D8202, so wie bei der 48K Karte. Meine 64K Karte wurde vermutlich auch baugleich in der P3 verwendet.

Ich fürchte, daß ich Euch daher nicht viel weiterhelfen kann

Don't let you down so easily, sir.

Intel 8203 has more modes than 8202 but according to the pinouts they don't seem to be that incompatible.

If not using the new modes, I imagine it could be even considered as a compatible replacement.

The P3 is more or less a P2 - les ROM, more RAM and also more cohesion between systems. many boards are identical for boths systems and bank switching mechanics are the same. My bet would be studying the P3 16k expansion boards: if the memories are managed from the other board, the rest of the logic should be bank-related,

Regards

Greetings,

Sorry, I am late

Quote from gpospi

• I also had issues with a P3, which suddenly stopped working (it did not boot anymore and just showed the flashing "RESET" message). Here we also suspected some RAM-related issues and tried to understand the RAM addressing logic. We investigated the switching from 48K+ROM mode into 64K RAM mode and tried to understand differences between P2-48K, P2-64K and P3-64K configurations. Unfortunately we did not complete these analysis successfully, hence these experiments do not provide additional insights into the issue of @overCLK's P2.
• Generic findings on memory boards for P2: I have one P2 with a 48K memory board and a second P2 with 3*16K memory boards. Hence I can confirm that the 16K boards work independently from 48K boards. However as mentioned above, I don't know if this is also true for the P2-64K setup. Usually there is this "adapter board" that is attached to the 48K board, allowing to "shift" the addressing (see http://www.wiertalla.de/pdf/Booten_Alphatronic_P2_cpm.pdf). Maybe in you case, this adapter board is now broken and you can try just the 48K RAM board in the machine (without adapter and extra 16K board).

In case for the P3, that's not always true. In my case my P3's 48K board and the 16k share signals through slot C. I don't have the documents I made right now but I recall the data bus to the memories to be dependent from the memories at the 48k board.

About the switching mechanism... A few months ago I build the entire 1MB sram board on breadboard and attached it into the backplane. To switch I used signal #mosen on the backplane (slot A or B?). Unfortunately it did not work and I'm still in doubt if it was poor wiring or the use of the wrong signal.

Regards

Quote from horniger

Quote from jlopez

Unfortunately I haven't found any background information about the computer itself other than its name "Wagner WAG.40"...

The Wagner WAC-40 was a mid range computer (mini computer) (MDT - Mittlere DatenTechnik).

The story of Wagner Computer is not a success story - mostly because Wagner was not interested in building (good) computers but in making money easily und fast:

https://blog.hnf.de/gauner-gelder-und-computer/

Do you already have a plan, how to read-out the software on your rope memory board?

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Amazing story!

I noticed the quotation has a line your post don't show... curious.

No, I don't have a plan to read the memory. I bought it for static display althought I was fully aware that the content is non-volatile, unless read (this kind of memory has destructive read, right?). So bad I don't even know the word size for it... The matrix is 128-bit but I don't know if it is 16 cells x 8-bit or 8 cells x16-bit. The required voltages are written on the board, so I imagine I could power it. Sounds funny but I have an overhead of months and will have to wait.

Greetings,

I got my first rope memory!

Unfortunately I haven't found any background information about the computer itself other than its name "Wagner WAG.40"...

I also received another core memory board, which is more compact and with more capacity, but is less interesting to see without some magnifying lens.

Regards,

Jaume

Quote from jlopez

As soon as the board arrives and I have some time, I'll report what I find.

Two days ago the board arrived as expected and, when I had some time just before lunch I made some tests.

(Top board, my Italian video system; Bottom board, Shiri 's Spanish video card)

First I checked (again) if there was no shortcircuit in any of the power supply lines. There was no problem.

I plugged the board at slor nº4 of the Italian unit and turned the system on, being greeted with the RESET message. So, with the new VTAC the board works, and so does with the second VTAC of the lot he bought. Then I proceeded to test the original 5027 only to find it is not broken. Both facts come as a relief as I was expecting a worst-case scenario. Still, even being great news they are confusing.

So...

The video card works as expected. No VRAM or EPROM fault.

The monitor was tested with a game console and found to be working.

His CPU initialized correctly the VTAC on both cases he tested it, judging by the cursor images he shared. So system ROMs seem to be fine.

Other than the power supply hack (which may prove to be unstable), could the wiring between computer and monitor be the cause of such distortion? Any other board interfering someway?

Regards,

Jaume

Greetings,

The board is in transit and may arrive as soon as tomorrow. Meanwhile I have checked again the SKS schematics. From the description and pictures, and if there isn't another problem with power supply (such as failing -12V on Shiri 's side or broken zener) I have reduced the options to four possible causes, involving up to eight components:

A) VRAM failure (D5, D6, E5, E6). If the memory was wrong and somehow it always outputs 80h the result would be a screen as the one shown. Still, I thing such a case is so remote that I'm sarting to rule it out.

B) 74LS175 failure (B4, B5). If the memories were fine but the EPROM doesn't receive a correct value, culprits would be this pair.

C) 74LS166 shift register failure (B6). If its output maintains a high or undefined value (not low) next component that feeds its inputs with this signal may pull it up and generate an inverted blank screen.

D) TMS2716 failure (A6). This is the worst possible case to be expected and also the most probable of all scenarios. Was the EPROM the cause, its data output could go high or undefined, making the shift inputs to pull them high internally and generating the inverted blank screen.

As soon as the board arrives and I have some time, I'll report what I find.

Regards,

Jaume

Hello helwie44,

After the replacement, image seems stable, at least from what I've seen. It is a perfect blank, but inverted screen.

Picture courtesy of Shiri

The replacement is a legit VTAC, otherwise we wouldn't see the cursor (or anything at all). This seems a fault from the video RAM, latches or maybe some other common component coming before the shift register because (as seen on SKS documents and later with the EPROM backups) MSB is the invert signal. As you said, the TA board is a modified SKS but this remains unchanged.

Yes, Shiri is a bit far, but even if he was near I couldn't meet him due to restrictions on mobility... Still, he sent me the board through mail. When it arrives, I'll give it priority over the PETs.

Kind regards,

Jaume

Greetings,

It's been some time. Last week the VTACs arrived and the one in the card was replaced by one of the Polish units. The image was stable, cursor moved but there was no character at all! The invert signal was also activated, so the screen was green with the exception of the cursor... This means, that the data path from the DIN to the VRAM and from the VRAM to the shift register should be checked. Being completely blank with the invert I imagine:

A) some 2114 may be faulty.

B) some 74 series IC in the bus may be faulty.

He has no scope to check the signals in the card... so he was stuck with it. For this reason, we agreed I would be in charge of the board for some time as I received one of such instruments not long ago. I don't expect it to be a long repair: as the VTAC retains most responsiblity for the generation of the signals, it shouldn't be as complex as a non-6545 PET.

Regards,

Jaume

Quote from Holger

Quote from jlopez

My father brought me some astronaut backpack!

The astronaut backpack is for an Amstrad PPC

Yeah, I know.

But it resembles one.

Greetings,

I have some new things and others that aren't that fresh but also worthy to report.

With this I regain the ability to repair hardware!

I found one of the rare tax-evading Amstrad computer!

I found many interesting things in dump piles near my home, including this ATMega, four breadboards, and some videoconsole boxes.

My father brought me some astronaut backpack!

Last, but not least, Toshi sent me the original monitor for the P2. This way, my Italian unit is complete. He was generous and never asked a price! So thank you very much.

Regards,

Jaume

Greetings,

A few months ago I was delighted when I learned the Deutsch word "Hamsterkauf".

It is my turn to expose a word from the country where I was born: "Estraperlo".

"Estraperlo" comes from the name of an electrical roulette made by two Dutch men called Strauss and Perlowitz. Albeit gambling was forbidden during the Second Spanish Republic, top public officials gave permission to them to operate. This corruption scandal was soon discovered and as most officials in the government were involved (including prominent members as the PM Lerroux and the mayor of Barcelona) prompted the third and last elections of the period, literally destroying the center-right parties and polarizing the country which went into a crude civil war not long after. When the war was over the word was associated with the black market and, after the postwar famine, with anything related to corruption, illegalities, black markets, etc.

You may be asking yourself: "Fine, but why is this guy talking about this in an old computers forums?". Well, to be fair, this is the Amstrad forums, I'm talking about Spain and also about something wrong (maybe even illegal) that shouldn't have ever happened. Knowing those facts, you may be already guessing what's going next.

The responsibles of this lied both to the authorities and to their users because they didn't want to pay some taxes... Spanish picaresque at its finest. It is not clear if it was Amstrad itself who gave the order or was the filial company in Spain who did it. Nevertheless, they never got caught. This is the second model, so "Ñ" key and standard BASIC 1.0 ROM (464)... was the older model it would have British keyboard and BASIC 1.1 (664).

I imagine that as it can only be found in Spain it may be rare to see this piece of hardware around this forums, so I thought you may be interested in seeing it.

Regards,

Jaume

Hello Helmut,

That's a relief. I told him the failure was most likely caused by the VTAC, but I wasn't completely sure. If that's the cause, the computer may be working very soon.

I haven't only guided him to find what was preventing the computer to start, but I supplied him my remaining ATX adapter and 48K replacement kits.

gpospi I was writing this when you replied. Thank you!

Regards,

Jaume

Greetings,

Last Friday another Spanish unit appeared. With both overCLK 's and mine's this is the third known unit to appear. This one is like mine and different from overCLK 's. As both units were found in Catalonia while overCLK 's was found in another autonomous comunity the conclusion is that the units sold in the Catalan market were different from the ones of the rest of Spain (which have that stylish Triumph-Adler badge).

As seen, the case is the standard one for the P2, but with the distributor badge (Guillamet) under the Alphatronic Sticker. My unit doesn't has the badge, apparently it was lost long ago but the glue is still there as a reminder of what once held.

On the technical side, the computer is also a little different. Up to that point all known P2 units were 64K units (even mine, which is not a "U" model). This one is the unupgraded 48K unit.

Now, the tests... the power supply is defective. It was shorting 5v, 12v and ground. All the boards were fine, there was no dead capacitor, even in the 48K DRAM card. With the boards in good shape I considered the computer to be ready for a test so I explained his owner how to wire an ATX into the backplane. After he checked the supply voltages from the backplane we considered it to be secure for the power up so he connected the three boards required for minimal operation: CPU, Keyboard and Video. The system resets correctly when powered on (also beeps as it should) and reacts to commands from keyboard. But the video display seems to be faulty.

The monitor is known to be working fine, so the fault is up to the video interface. I think his problem is CSync but I would like to know what do you think the problem would be. VTAC?

Note: this unit is not mine and I haven't even seen it other than i pictures and a couple of videos, the images posted here were uploaded with the consent of his owner. I'll try to convince him to come here. When he rescued it he said there was some possibility he had the Spanish manuals but after a search he found none. Still, the simple fact to appear was enough to give me one of the best days of the year.

Regards,

Jaume

Greetings and sorry for the long wait.

There were incidents at home that left me without the mood to continue in projects. Recently I have made some progress.

Sometime ago I found some breadboards in a junk pile. They are tattered, two of them a bit melted and one lacks a row of contacts. Still, I found them to be reliable when used, I later saved some money and bought more of them and wires and have started prototyping as I should have from the beginning. It was expensive for my current budget but I was tired of not having a proper tool set. And so, I resumed development.

My experiments with sound were halted in february and since then I learned much more. Still, I had preference on digital over analog electronics and as a result the first complex circuits I made with my new tools are digital.

I compared what I had done whith one of the most common systems with sound (NES) and found my developing to be far behind. And so I challenged myself to get the closest I could. I think that, with the exception of the DCPM channel, I got near.

I first built the noise generator. It consists of a 17-bit LFSR: Noise Test

Then I made the pulse wave generator with variable duty cycle: Pulse Test (Failure)

This circuit was inspired by the Hellschreiber as I was wondering how would its characters sound. Then I realized if the character ROM was replaced by another circuit whose function was creating a single character, I could easily implement the variable duty cycle. The character is exactly this one:

0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 1

0 0 0 0 0 0 1 1

0 0 0 0 0 1 1 1

0 0 0 0 1 1 1 1

0 0 0 1 1 1 1 1

0 0 1 1 1 1 1 1

0 1 1 1 1 1 1 1

Then I resorted to video circuits, especially the one found in early PETs and the SKS KISS. The resulting circuit was designed by stripping them down. Still, it was a failure. Somehow it produced an awful noise when it shouldn't. After debugging it was found the only 74LS166 shift register I had was defective by failing to output high but it worked fine when outputing low. I patched the circuit with a 10k resistor from the 5v supply pin to the output and worked. Still, the circuit was so sensible that every time I approached my hand it started to generate noise: Pulse Test (Fixed)

Finally, the sawtooth/triangle section. It just needed a synchronous counter, an XOR ic and some logic to control the invert operation. This means that with simple logic I could generate three different tones. And three tones is what I got. Unfortunately, I'm unable to discern an inverted sawtooth from a non-inverted one: Sawtooth-Triangle Test

On the analog side, I found some operational amplifiers in my father's stocks of components and started to test them. I start to realize they aren't as complex as I thought and, whith some time may even domesticate them just a little.

Regards,

Jaume

Greetings,

About two years ago I rescued an old AIM/65 with its original documents and many papers. Recently I took a look at those papers and found some interesting information. Comelta not only imported and distributed the AIM/65 in Spain: over time their "expansions" for it became part of a stand-alone computer mounted in a backplane. Prior to the release of "Drac-1" ("Dragon-1" in Catalan), they called it CR-System and apparently its boards were sold apart. While some of the boards are known, I found more board references which can help in making a more comprehensive list. I also found some prices and a release date for some of the boards. My backplane pinout document is slightly different from the only other source I found (mine has a battery supply line). Additionally it is also headlined with "Development Laboratory".

Unfortunately, there are no schematics but simple descriptions for many of the boards. I uploaded the scans here.

Regards,

Jaume

Quote from PAW

did I understood well, that you put off all components of the PCB to get an empty board? Then you want to draw a circuit diagram of the board?

In the 1990s a colleague and I did a similar job, but we did not destroy the original Z80-interface-board. He checked the circuits on the board with an ohm-meter. So we got a big chart with all connections of the components. I disassembled the EPROM. So we could redesign a new board with similar functions.

If you have really an empty board (hopefully it is only double sided and not a multi layer), you can scan it with a flat bed scanner on both sides. Then you can try to colorize the sides in different colours and make them semi transparent. Then you can overlay them to get a good overview.

I think it will be a lot of work, but you will get a good documentation for your system.

I wish you good luck!

Kind regards

PAW

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Removing them all was a must, certain components can interfere multimeter readings (low impedance resistors, dead capacitors, etc.). And yes, I was going the scanner way (scanners don't have either lightning or perspective problems). You read my mind.

Just for the record, months ago I had the backplane documented, but I don't remember where did I post it... Those documents may belong to this thread now and for this reason I'm uploading them here too.

Thank you very much,

Jaume