DDI-4

[LambdaMikel]

Any update on this one, @TotO ? Your experience with it?

[TotO]

Any update on this one, @TotO ? Your experience with it?

Sorry, I was not able to test it last time (only a weekend for me) and I will return at home only in 2 days...   

[TotO]

It not works on my CPC 464... I have to do more tests. May be a problem with the edge connectors.

[LambdaMikel]

It not works on my CPC 464... I have to do more tests. May be a problem with the edge connectors.

What did you connect? FD1? In that case cable mod is required it seems...

[LambdaMikel]

Since nobody ever followed up on this one, and the question of 2x 3.5" disk drive on the DDI4 cropped up on another CPC board, here is my latest DDI4 desaster - in principle I am no longer using it because I do not want to damage my CPC, but I tried to help another CPC user with this:

https://youtu.be/N8hR2yOVSz4
If anybody has an idea why the CPC is crashing between 6:03 and 6:54 and after that refuses to turn on, and why the DDI4 power / voltage regulator after 5 minutes of disk operation gets so hot that I can no longer touch it, please let me know! 

Does anybody have a working / reliable 2 drive with DDI4?
Both Mitsumie DS395T5 are modded for READY and one is DS0, the other DS1.

I should add that this CPC freezing also also happens after 5 minutes of normal operation, so it has nothing to do with Discology... see second picture.

In principle, I am more than done with DDI4 "bashing", but I am curious if other users encounter similar problems. Maybe I just got a bad one and everybody else is happy. Having said that, I am not using it since March and I got reimbursed, so no hard feelings. But I would advise all DDI4 users to be extra careful and have a close eye on what it might be (potentially harmfully) doing to your CPC.

[rpalmer]

LambdaMikel,Does the DDI4 work fine with just 1 drive?
If the DDI4 were to cool down (after a power down), does the CPC boot up normally?

It would seem strange for the CPC to not boot up, but the voltage regulator may have a thermal shutdown which may be in effect be causing a Low IR and thus low voltage on the CPC itself.
rpalmer

[LambdaMikel]

when it cools down the cpc powers on again.
you can see and hear how scary this is to the cpc... go to the video between 6:25 and the end and turn on the volume to really really loud max. you will see and hear that when the cpc is not booting (but gets power) one actually hears a low pulsing frequency tone / sound from the cpc speaker, which gets higher and higher... I turned it off again after 10 seconds obviously, but it seems that this could be such an effect form the voltage regulator turning on and off as the temperature cools down. there is some kind of weird electrical oscillation going on. maybe even my cpc power supply plays a role in that feedback cycle, because i think it has a auto shut off regulation as well.


the same effect also happens with only one drive attached, but it may take longer to occur.

[LambdaMikel]

Somebody requested hi res pics.

[LambdaMikel]

More

[LambdaMikel]

Upon close inspection I found that 2 solder points were forgotten... see RESET BUTTON... 
I have fixed that, let's see if it makes a difference...
EDIT - not it doesn't... only added stability...

[LambdaMikel]

One more

[LambdaMikel]

One single 3.5" floppy is enough for it to get hot.
Check this one out - this time I was brave / courageous and didn't turn the CPC off immediately when the Power Surge / Overheating Effect kicked in. You can hear crazy stuff going on in the CPC speaker. Enjoy:


https://youtu.be/GRiq0Dn3z68

Still open to ideas what I am doing wrong! (If anything)

So, either 1 or 2 3.5" drives cause the effect reproducibly within 5 to 7 minutes. With a Gotek drive, it takes about 45 minutes for it to occur. The drives were powered externally with a stabelized PSU.

I'd like to point out that other CPC 464's from my collection show the same problem, and that everything works fine with a DDI and second 3.5" Mitsumi drive and/or Gotek.

[Audronic]

@LambdaMikel


Can you put a CRO On the output of the Regulator on the ddi-4 and see if its oscillating ?


Ray

[Bryce]

In your hi-res picture, C20 seems to be the wrong way around. That won't help. The regulator is probably going into oscillation and the tantulum cap is probably shorting to ground until it cools back down. Try removing C20 and see if the issue persists.

Bryce.

Edit: Looking at one of the other pictures, it may not be the wrong way around, but I'm not sure what it's connected to. I would expect one side to be to ground.It should also be mentioned, that using a tantulum cap on a regulator in this fashion isn't a very good idea. Ideally, electrolytic caps should have been used.

[LambdaMikel]

Can you put a CRO On the output of the Regulator on the ddi-4 and see if its oscillating ?

Yes I can do that... but will have to wait until the weekend.

[LambdaMikel]

Hmm, @Piotr  on my YouTube video says that "You have connected it wrong - or you burned it".
Well, that's not helpful. Please tell me what I have done wrong! I thought it should be as simple as plugging in a cable and powering the floppy with a MOLEX connector and external PSU...

I have deleted the comment. He and his following are disliking the video. That's not helpful either  If you have something constructive to say, say it here. 

[LambdaMikel]

Since this is going wild on the YouTube video, I have disabled all comments. If you should have something constructive to say, do it here. Thanks.

[robcfg]

If you can connect it wrong and break it, then it's not a good design... 

[villain]

If you can connect it wrong and break it, then it's not a good design... 

Sounds like a ZX Spectrum... 

[LambdaMikel]

All, it is not my intent to bash the DDI4 or any of Piotr's work.I am a big fan of his DDI3 and use it daily. He certainly made a lot of great hardware extensions and I am grateful that he is one of the few sources for that stuff.

I am by no way saying that all DDI4 have that problem or that, but I am saying that mine does, and no arguing discusses this fact away. Again, I have no hard feelings since I got reimbursed.

Still, it would be good for the sake of all CPC and DDI4 owners / users to verify that you device does not have a similar problem.

Who knows, maybe the oscillation is related to the US power grid with 50 Hz instead of 60! Whatever it is. All I am saying is - be careful, for me it doesn't work and it is potentially harmful to the CPC.

Take it or leave it, for me this discussion is tabled. I can make some more tests such as measuring the regulator output with a scope to check for the oscillation, but then I am done. I am not using it.

So, if you are happy with it, be it! However, I reserve the right to disable or block comments that are not helpful on the Youtube video in an attempt to divert the discussion to this place here. Where it is more useful.

I said what I had to say. That's it.

[Sykobee (Briggsy)]

My DDI4 doesn't get hot, but my disc drive unit is going cranky and doesn't recognise disks. With the DDI-1 it tries to read them then read failed, with the DDI-4 it says Disk Missing.


I'll try a Gotek but I need to sort out the 5V supply for that, maybe there's a CPC 5V floppy power adapter (I'm already using a 5V SCART mod off the 464).




Edit: I could stick the gotek in the 3" disk unit I guess, with the top off to fit.

[LambdaMikel]

My DDI4 doesn't get hot, but my disc drive unit is going cranky and doesn't recognise disks. With the DDI-1 it tries to read them then read failed, with the DDI-4 it says Disk Missing.

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.
You can mod your drive for this; the Mitsumis I was using are the easiest to mod for READY.
The cable hack for READY (putting it to VCC - or was it GND?) does NOT work for the DDI4, you need a proper READY signal. Also, if this is the only drive and |A, then set the SMD jumper to DS0. Otherwise, the ABBA switch will work.


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).


For me, it makes no difference if I use the CPC PSU or an external PSU just for the floppy. Eventually, the effect kicks in and the regulator gets hot. 

[LambdaMikel]

In your hi-res picture, C20 seems to be the wrong way around. That won't help. The regulator is probably going into oscillation and the tantulum cap is probably shorting to ground until it cools back down. Try removing C20 and see if the issue persists.

Actually, looking at this close up, I think you are right... if the ground copper is GND (this is what I assume), then one can clearly see that the C20 has + connected to GND... yikes. 

It is true that this CAP C20 ALSO gets very hot when the effect kicks in. As hot as the regulator actually.

THANK YOU @Bryce and @gerald  !!
You guys rock. I wish other hardware builders (not mentioning any names here...) would have a similar open mindedness and not assume their customers are dumb as .... not knowing how to power a floppy drive or what have you. Anyhow.

Great! So let me reverse that thing and check if this makes a difference. I am pretty sure it will, because it got EXTREMELY HOT AS WELL.

@Piotr are you reading any of this?? All the other "haters" and thumbs down people on my video - you can stop now, people with a more open mind than you have figured it out. Thanks again.

In a world where manners would still matter I would have expected an apology from a couple of people, but this is the internet...

[LambdaMikel]

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

Thanks again @Bryce and @gerald

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
• if anybody has a solution for this, please let me know
• that also makes it impossible to have the FD-1 and another drive connected to the DDI4
• you can connect 2 3.5" disk drives without problems, and then the ABBA switch works and A B works, but as soon as FD-1 is part of the setup, it's becoming a "one drive only" solution
• 3.5" drives needs to emit the READY SIGNAL
• the READY signal cable hack does not work with the DDI4
• also, then one 3.5" drive needs to be jumpered as DS0, the other as DS1
• it is also possible to use HxC and Gotek, in combination with a 3.5" disk drive
• my current setup consists of a Gotek FF as A, and a 3.5" Mitsumi floppy as B. Works fine now.

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!
  

Well, it has been quite a ride. I got reimbursed and got a free DDI4. No hard feelings - I had to work hard though in order to "earn" it. So I think I deserve a free DDI4 for all that (unpleasant) drama.
Hope that helps.

[Bryce]

Hi,    I was about to get back to you to confirm the cap is definitely backwards, but I only got a chance to look at the hi-res pics this morning and it looks like you've already confirmed it for yourself.

Sadly, this also means that the devices are neither being visually nor sufficiently electrically tested before being shipped. Not acceptable.


Bryce.

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.