DDI-4

[LambdaMikel]

Yep, well what can you say...  Happy it was only one CAP and one set of forgotten pins, could have been worse. And my CPC did not get damaged. Post surgery pic attached.

Bryce wrote:

Edit: Don't use the same capacitor, replace it with a new one. The heating and reverse polarity will have done serious damage inside it and when they completely fail, they go out in flames.

Upps!! Both of them? Would you have a source available?  I guess I have to figure out the specs first, or is it possible to tell from the markings?

[Bryce]

Use a new capacitor, that one will be badly damaged inside and could flame out at any time. When tantulums fail, they can take quite a lot more with them.

The failure it was causing won't have caused any damage to the CPC luckily.

Bryce.

[gerald]

   
• all DDI4's have the problem that you can connect a FD-1 3" Amstrad, but then you will need to short / bridge cable pins 23 and 24, otherwise you get "No disc"
• moreover, the FD-1 then always reacts to A and B, and the ABBA switch doesn't make a difference
• if anybody has a solution for this, please let me know[/l][/l]

That's the result of AMSTRAD choice : all amstrad external drive react to both drive selection signal : DS0 and DS1 are connected together on the adaptation board that do the 34 to 26 pin conversion.
On the DDI1 interface the actual selection is done at cable level by removing one of the drive select pin in the IDC connector.
Do you have 2 choices :
1. do the same on your cable
remove pin 23 (DS1) on the outer connector -> this will be drive 0
remove pin 25 (DS0) on the inner connector -> this will be drive 1
If you short DS0/DS1 on your 3 1/2 drive, the position on the cable will just decide if these are A or B
2. mod the FD1 to only get one drive select
either permanently by cutting one of the track on the adapter board within the drive
or putting a switch that let you select DS0 or DS1

[/list]

[Sykobee (Briggsy)]

OK, then you haven't used it yet it seems.

The Disc Missing issue is different - you need a drive the emits a proper READY SIGNAL.

It's an FD-1. I should have clarified. Because the DDI-1 is also having problems I'm guessing the drive needs some TLC. I see that adding a Gotek will likely not recreate your issue however.

For the 5V CPC power adapter, you can ask @ikonsgr who is selling them (CPC plug compatible socket -> MOLEX and 2 CPC compatible plugs, Y cable).

Thanks, I'll look into them.

[Sykobee (Briggsy)]

I am happy to confirm that reversing C20 has fixed the power issues and overheating.

I'll take mine apart and check it for the same issue.

So, to sum up my DDI4 experience:

   
• all DDI4's have the problem that you can connect a FD-1 3" Amstrad, but then you will need to short / bridge cable pins 23 and 24, otherwise you get "No disc"
• moreover, the FD-1 then always reacts to A and B, and the ABBA switch doesn't make a difference

Yes, this explains what I see with the FD-1. It also responds to both A and B. I'll have to do the FD-1 track-cut + add switch mod I guess.
I'll try the Gotek.


But I did rather want to have both the Gotek and the FD-1 connected up. I guess I'll have to swap DDI-1 and DDI-4 depending on need.

[LambdaMikel]

That's the result of AMSTRAD choice : all amstrad external drive react to both drive selection signal : DS0 and DS1 are connected together on the adaptation board that do the 34 to 26 pin conversion.
On the DDI1 interface the actual selection is done at cable level by removing one of the drive select pin in the IDC connector.
Do you have 2 choices :
1. do the same on your cable
remove pin 23 (DS1) on the outer connector -> this will be drive 0
remove pin 25 (DS0) on the inner connector -> this will be drive 1
If you short DS0/DS1 on your 3 1/2 drive, the position on the cable will just decide if these are A or B
2. mod the FD1 to only get one drive select
either permanently by cutting one of the track on the adapter board within the drive
or putting a switch that let you select DS0 or DS1

Great, good to know, thanks! Will try that.

[LambdaMikel]

I'll take mine apart and check it for the same issue.

Probably unnecessary unless you have observed the same issue as I (maybe don't break away the casing too early). I openened it when I smelled something burning  and the plastic got very hot and started to smell.

[LambdaMikel]

It's an FD-1. I should have clarified. Because the DDI-1 is also having problems

Right, see my comment that bridging cable pins 23 & 24 solves this issue, but the drive reacts to both A and B then. And then see @gerald 's comment regarding drive select lines as well.

Actually, now I am not sure if it was 23 & 24 or 11 & 12 that I bridged; 11 & 12 would make more sense according to

http://www.cpcwiki.eu/index.php/Guide_on_how_to_connect_a_3.5%22_drive_to_a_CPC6128/664

Since 23 & 24 would just "Floppy Write Enable"...

https://old.pinouts.ru/HD/InternalDisk_pinout.shtml

Have to count my pins again.

@Gerald, I guess pin 23 -> pin 14 (DRIVESELB) and pin 25 -> pin 12 (DRIVESLA) right?


So I either did DRIVESLA or "Floppy Write Enable" to make it work... let me check tonight.

[gerald]

Right, see my comment that bridging cable pins 23 & 24 solves this issue, but the drive reacts to both A and B then. And then see @gerald 's comment regarding drive select lines as well.

Actually, now I am not sure if it was 23 & 24 or 11 & 12 that I bridged; 11 & 12 would make more sense according to

http://www.cpcwiki.eu/index.php/Guide_on_how_to_connect_a_3.5%22_drive_to_a_CPC6128/664

Since 23 & 24 would just "Floppy Write Enable"...

https://old.pinouts.ru/HD/InternalDisk_pinout.shtml

Have to count my pins again.

@Gerald, I guess pin 23 -> pin 14 (DRIVESELB) and pin 25 -> pin 12 (DRIVESLA) right?


So I either did DRIVESLA or "Floppy Write Enable" to make it work... let me check tonight.

pin 23/25 are the one on the DDI1 service manual (ready on pin 1), but it's pin 10/12 on shugart pinout (ready on pin 34)
Now if you look at the IBM/PC pinout, you will see that only a B drive would work (Drivesel / motoron) and that how most 3 1/2 drive are configured.

[LambdaMikel]

pin 23/25 are the one on the DDI1 service manual (ready on pin 1), but it's pin 10/12 on shugart pinout (ready on pin 34)
Now if you look at the IBM/PC pinout, you will see that only a B drive would work (Drivesel / motoron) and that how most 3 1/2 drive are configured.

I see, right... and this is where the cable twist thing comes into play. Thanks!

[LambdaMikel]

@gerald just to clarify - the attached picture is from the FD-1 service manual.
I have highlighted the two drive select lines. Correct?

One can clearly see how 4 and 6 are connected on the PCB (DRIVE SEL 0 and DRIVE SEL 1), and that they are coming from 23 and 25. So, as you said, both drives react to SEL0 and SEL1. And, as you say, then the cable connector for A has only the SEL0 line, and the cable connector for B has only the SEL1 line. Interestingly, the schematics don't show that! Did they want to obfuscate / hide that? The only difference the schematics show for A vs. B is the 5V power supply that comes from A.

Thanks

[LambdaMikel]

So, I have corrected the schematics - it should look like this, right?

[LambdaMikel]

Thanks to@gerald 's excellent help I can now confirm that the DDI4 works fine with FD-1 and Gotek.I have made the special cable, and Gotek is |A, FD-1 is |B. Power for the Gotek comes directly from the FD-1.

[gerald]

@gerald just to clarify - the attached picture is from the FD-1 service manual.
I have highlighted the two drive select lines. Correct?

One can clearly see how 4 and 6 are connected on the PCB (DRIVE SEL 0 and DRIVE SEL 1), and that they are coming from 23 and 25. So, as you said, both drives react to SEL0 and SEL1. And, as you say, then the cable connector for A has only the SEL0 line, and the cable connector for B has only the SEL1 line. Interestingly, the schematics don't show that! Did they want to obfuscate / hide that? The only difference the schematics show for A vs. B is the 5V power supply that comes from A.

if you look closely to the diagram, you will see that the dot are smaller where the pin is missing. The error is on pin 33 where there is no dot

So note that in addition to the sel line, B connector also have pin 33,31,29,21 removed (the 5V from the drive)

[LambdaMikel]

if you look closely to the diagram, you will see that the dot are smaller where the pin is missing. The error is on pin 33 where there is no dot

So note that in addition to the sel line, B connector also have pin 33,31,29,21 removed (the 5V from the drive)

Oh wow, I would not have thought that this means something! Why no just remove the dots like I did in the pic?? That would have made it much clearer. I guess the low-res scan didn't help that either.

Yes, I have unplugged the internal 5V molex in the FD-1 such that no 5V power flows into the Gotek...
So, now I really need the new CAPs before I can use it...

[LambdaMikel]

So, to sum up my DDI4 experience:

   
• works fine with Gotek FF,  HxC, appropriate 3.5" floppies, and Amstrad FD-1 3" drive
• 3.5" drives needs to emit the READY SIGNAL
• the READY signal cable hack does not work with the DDI4
• works fine with Amstrad FD-1, but requires a special cable for dual drive:
  thank to Gerald, you need to
  remove line 23 from the cable for drive A, and remove line 25 from the cable for drive B.
  This is only necessary for two drives, obviously.
  also remove the 5V molex inside the FD-1 that feeds 5 V into the cable to the Gotek... the Gotek would probably not like. The 5V produced by the FD-1 can be used to power the Gotek or HxC or 3.5" floppy instead!
• for one single Amstrad FD-1 drive, you will ALSO need to mod the cable - in this case, it suffices to bridge the two pins in the other connector. Otherwise, you will get "Disc Missing"
• don't use twisted PC floppy cables. Just straight one-to-one ribbon with 2 connectors for the drives.
• my current setup consists of a Gotek FF as A, and a Amstrad FD-1 as B.

With my specific DDI4, it had these problems:

   
• the tantulum cap C20 was put in reversed, hence causing overheating and electrical oscillation. fixed.
  
• the RESET BUTTON was not soldered in properly; 2 solder points were forgotten. fixed.
  
• customer support... not fixed.
  

Something else positive:

   
• BATMAN FOREVER DEMO RUNS THROUGH with DDI4 !! GREAT!

[LambdaMikel]

- remove pin 23 (DS1) on the outer connector -> this will be drive 0
- remove pin 25 (DS0) on the inner connector -> this will be drive 1

Obviously, one can also swap inner and outer - in my case, I wanted the Gotek to be A, but still be sitting on top of the FD-1, so I ended up swapping "inner" and "outer". The resulting cable avoids the "twist" then and looks much neater.

In order to make it, I crimped on the inner connector to a standard PC floppy cable, which has cut out line 23 before the end connector (-> A for Gotek),  and then before crimping on the inner connector for the FD-1 I pulled the metal crimp pins for line 25 (-> B for FD-1).

[TotO]

Just opened mine, and I confirm the C20 capacitor was inverted.
Looking the others DDI from Piotr, they looks inverted, but are not. Because the ground is not coming from the same side.

To resume:
- All looks visually the same (that was the mistake while assembling)
- DDI3 (lcd screen) for 464 is OK
- DDI3 (no screen) for 6128 is OK

[LambdaMikel]

Just opened mine, and I confirm the C20 capacitor was inverted.

Oh, so yours got that too? And it worked, it did not overheat and shut down the CPC after 5 minutes?

[TotO]

Yes, I would like to do the test while I was at Madrid with friends, to see with us...
After 30mn, but it was used on my X-CPC board and may be it took less power and not overeat too fast.

I thing, if Piotr does serious tests before assembling all the boards, and not power-up / power-down, he was able to detect the invertion from the DDI4 design. Is it too hard to wait 8 hours to valid a design, before the real production?

[Bryce]

If you were using a very clean supply (Bench supply for example) the capacitor wouldn't really be required and it would all work more or less as expected. That still doesn't excuse such bad production/testing processes. You test things in a worst case scenario, not best case.

Bryce.

[LambdaMikel]

Well, yes, unfortunately it underlines my previous advice to other DDI-4 users to check their device... which unfortunately means you'll have to break open the nice 3d printed case  Mine was glued, plus screws.

[TotO]

Only screws on mine... The label was properly removed with something to dissolve the glue.
Best for users is to not buy the DDI-4 while Piotr do not communicate about a revision with the problem fixed.

[deepfb]

Only screws on mine... The label was properly removed with something to dissolve the glue.

Just an aside: it was gasoline :-D



If you need to remove stickers and are not confident using the heat of a reworking station, lighter fluid is perfect. It does not leave marks, you just need an x-acto knife to peel off the sticker, and the glue will stick again once the gasoline has vanished. It is not indicated, however, to remove/replace/fake security labels.

[LambdaMikel]

Only screws on mine... The label was properly removed with something to dissolve the glue.
Best for users is to not buy the DDI-4 while Piotr do not communicate about a revision with the problem fixed.

Well, he DOES communicate, just not here and not to solve the problem. Rather, he is posting "stories" and alternative facts and "fake news" on CPC Fakebook Group. And his following is then giving "thumbs down" to the person that brought the problem to their attention in the first place, in their (CPC's) best interest. So, yes, let's shoot the messenger, there IS no problem. The messenger is just too stupid to use a great piece of hardware. Great new internet world where the truth doesn't matter that much anymore. Rather, propaganda. Anyhow, I should not be starting again...

I was even told that he was going to close down his shop now because there is too much trouble with all of this "cyber bullying"; for now, there are only 22 auctions so maybe this is the "closing sale" of his shop??

https://www.sellmyretro.com/user/profile/zaxon
Anyhow. All I am saying is BE CAREFUL with the DDI4 and check it!