Wanted - working Memory Expansion for CPC 464

[LambdaMikel]

Yeah I remember reading that at the time. I thought he pulled them off sale because of the problems

And he did while he investigated and reengineered. The new version is working much better than the previous one and honestly, the 4 MB is working "well enough" for most people and for what they are doing with it, so there is no reason not to buy it - I mean, I also tested the 4 MB Aha video demo etc. and it works great. As I said, this is only about the 464 and 64 KB DKtronics part of it. Which is not working that great with some demos. I am not saying that this is a bad expansion, it is not, but I am saying that the DKtronics mode has issues on the 464.
There is one more thing I will try - I'll solder it directly into my 464 expansion port connector. Let's see if that makes a differnece. I noticed that, even if the card has a very firm fit in the IDC header socket on the expansion board connector, it makes a difference if it is slightly angled, or no. I want to remove all potiential insufficient contact issues from the equation and test one more time.

[tjjq44]

For reference, here was some previous discussion, including the pictures and stats of the 464's on which I had tested:
http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/4mb-externial-ram-expansion-will-be-soon/100/

Yes, i've already read this thread, it confirms this card seems to work with some cpc 464 but not all... Sounds very strange to me that's why I want to make my own tests ;-)

It's not for tommorow since the seller is in vacation till the end of october... to be continued...

The new version is working much better than the previous one and honestly, the 4 MB is working "well enough" for most people

Hope the 512k expansion is "new version" too...

I'll solder it directly into my 464 expansion port connector. Let's see if that makes a differnece. I noticed that, even if the card has a very firm fit in the IDC header socket on the expansion board connector, it makes a difference if it is slightly angled, or no. I want to remove all potiential insufficient contact issues from the equation and test one more time.

Soldering may be difficult to revert... personally, I use Q-tips and rubbing alcohol one the edge connectors and a little bit of WD40 after that, all my expansions (multiface 2, DDI1...) work fine this way 

[Vyper68]

Cannot get it to work at all - Blue screen of Death for both the Single Disk and Multi Disk set, probably need a DDI3 or similar and not the M4. When I boot SymbOS in my M4 it recognises 576KB of RAM.

[LambdaMikel]

Soldering may be difficult to revert... personally, I use Q-tips and rubbing alcohol one the edge connectors and a little bit of WD40 after that, all my expansions (multiface 2, DDI1...) work fine this way 

Yeah, that's not really the issue though (I cleaned my expansion port many many times in the process of running these test....  )
I'll solder it directly onto one of these

http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/sharing-is-caring/msg154873/#msg154873
there is no better and tighter and shorter contact possible than this with a 464. It doesn't have to be revertible, I'll use it for the 464 only.
Then, after the mem expansion, I use a cable to the DDI3, such that there is zero physical stress on the CPC expansion port connector. I have tried dozends of combinations for connecting the DDI3 to the expansion port, see here:

http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/mother-x4-and-ddi3-mods/

[Vyper68]

Yes, i've already read this thread, it confirms this card seems to work with some cpc 464 but not all... Sounds very strange to me that's why I want to make my own tests ;-)

It's not for tommorow since the seller is in vacation till the end of october... to be continued...


Hope the 512k expansion is "new version" too...

Soldering may be difficult to revert... personally, I use Q-tips and rubbing alcohol one the edge connectors and a little bit of WD40 after that, all my expansions (multiface 2, DDI1...) work fine this way 

Yes I was going to get the CPC6128 Mini USB Disk Drive until I saw he was away.

[LambdaMikel]

Hope the 512k expansion is "new version" too...

When I had it, I had to break of the 3d-printed case, because the plastic case did put some stress on the edge connector which results in bad contact.

[tjjq44]

Encouraging... 

[Vyper68]

Hope the 512k expansion is "new version" too...

Mine is only two/three weeks old so you would get the same as mine I guess. No better or worse than the one I have sat on my desk.

[Vyper68]

When I had it, I had to break of the 3d-printed case, because the plastic case did put some stress on the edge connector which results in bad contact.

I pulled my case off altogether after 10 minutes. I pulled the back off when I unplugged it from the 464 and I decided to take the rest off in exasperation.

[tjjq44]

I suppose this 512k memory will work fine on my 6128 at least...

Revaldinho come back please!!! Our last hope for our poor 464s, we need you

[LambdaMikel]

Cannot get it to work at all - Blue screen of Death for both the Single Disk and Multi Disk set, probably need a DDI3 or similar and not the M4. When I boot SymbOS in my M4 it recognises 576KB of RAM.

You mean Batman with One Disc Version? Yes, that requires DDI3 or similar But the multi disk versions should at least load... you get nothing?  What's your exact setup with the RAM expansion, and where does Batman fail?

[Vyper68]

Hi
So I have a 464 with the M4 and the 512KB Expansion plugged in with a decent PSU and a powered RGB SCART Lead into the TV. There is nothing else plugged in or any other modifications.
I navigate to the Disks on the SD card get inside and RUN"DISC there is a brief moment of activity on the SD Card then nothing the Screen is just Navy Blue and stays that way until I reset it.
So I don't know what the problem is, like you say the standard 3 disk image set should work, but not for me.

[LambdaMikel]

Hi
So I have a 464 with the M4 and the 512KB Expansion plugged in with a decent PSU and a powered RGB SCART Lead into the TV. There is nothing else plugged in or any other modifications.
I navigate to the Disks on the SD card get inside and RUN"DISC there is a brief moment of activity on the SD Card then nothing the Screen is just Navy Blue and stays that way until I reset it.
So I don't know what the problem is, like you say the standard 3 disk image set should work, but not for me.

Alright, I never tried this with the M4... I think the disk emulation of M4 has its own problems, and is IMHO opinion not as mature as DDI3 - I remember I ran into an issue that it was not able to load Roland in Space, only a certain cracked version. Duke explained why this was the case, but he also said he didn't find that an important enough bug to push an upgrade to the firmware which honestly I couldn't quite understand (after all, it failed to load a perfectly fine standard DSK image which no other DSK emulator - ie DDI3, HxC - had no problem with). Anyhow, maybe the next |upgrade will fix the issue? I get that DSK emulation is not the M4's primary point, but still it would be nice if such rather big failures could be fixed timely.   

I can try with my M4 and let you know, but I am pretty confident that this is the M4 which is causing the overall failure here. Maybe let me try, and if I also fail at this, we call out for the @duke

[tjjq44]

Nothing worse than crossed bugs... I know what I'm talking about!!


Best thing is to try to isolate each component. On my side I don't own any M4 nor any gotek/hxc, I still use good old floppies 


But why floppies???
_ Because I love the sound of old disk drives and mine are old enough so fully compatible (real ready signal).
_ My every day computer is a 10 years old (high end) PC whith floppy controller and running windows XP SP2.
_ I have a parados 1.2 rom (2015, great version) inside my 6128 (with amsdos switch) and my old 1.0 that I fitted in my DDI1 interface when I burn the new 1.2 so I can use 720k disks on both CPCs.


Hopefully, that'll make my tests more accurate eliminating other eventual hardware issues.

[LambdaMikel]

Nothing worse than crossed bugs... I know what I'm talking about!!
...
Hopefully, that'll make my tests more accurate eliminating other eventual hardware issues.

Sure, it's a good idea to test it with real floppy.... I should do that too. Who knows, maybe it is caused by an interaction / incompatibility between RAM module and DDI3? Although unlikely, since same developer.

[LambdaMikel]

Hi
So I have a 464 with the M4 and the 512KB Expansion plugged in with a decent PSU and a powered RGB SCART Lead into the TV. There is nothing else plugged in or any other modifications.
I navigate to the Disks on the SD card get inside and RUN"DISC there is a brief moment of activity on the SD Card then nothing the Screen is just Navy Blue and stays that way until I reset it.
So I don't know what the problem is, like you say the standard 3 disk image set should work, but not for me.

Same here. No success with the 3 single DSK files found online, neither in real DD1 floppy, nor in DDI3, nor in HxC. Same with and/or without M4, but the directories of the single DSK files show up weird in M4... there is nothing to run (no "disc" file)

The only thing that works is the one DSK version, and only in DDI3.

I am wondering if somebody has working single disk Batman DSKs?
@Rhino  - are the single DSK version supposed to work on the 464 with DKtronics? After the load screen, they hang, whereas the single DSK version continues. Same equipment.

https://files.scene.org/view/parties/2011/forever11/cpc/demo/batman_forever.zip

[tjjq44]

Just tested the 3 amsdos dsk version (on my 6128 since I don't own any ram expansion for now). Floppies made with CPCDiskXP.


Work fine, the DSKs from your link aren't corrupted. Here's the catalog :

[tjjq44]

Just tried on my 664 and it doesn't launch (of course)... nevertheless I get a message on the screen ;-)



These DSKs seem a little bit weird however, since I can't "log" them in my parados utility... read fail!!! Non standard formatting for sure, maybe M4 or HXC don't like it? You said you also tried with real DDI1, how did you make your 3" floppies?

[Duke]

Batman demo will not work with M4 board, nor any other game or demo that uses direct FDC I/O access. For M4 board to work on all CPC models (those with and without FDC) it cannot respond to FDC I/O ports, therefore dsk images are only running through software patches (firmware functions).

As for 464 memory expansion, my coming boards should fully support C3 mode for 464 (similar to 6128).
Also I am fairly sure that XMEM supports "Dk'tronics" C3 mode, so if the fails in Batman demo are due to that mode, maybe it is a timing issue.
It would be interesting to make a memory tester for all extended modes. Maybe I'll find some time to do that, as I have done some partial tests already.

[LambdaMikel]

You said you also tried with real DDI1, how did you make your 3" floppies?

I used Discology Ultra Copy from HxC copied over to 3" disk. See here for setup:
http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/'modern'-way-of-creating-physical-3'-disks/(picture at the end)

[Rhino]

Hi!
Today I tested BF on my 464 + dd1 + dkTronicks 64kb and it works fine (I have not tested it for more than 5 years :)When testing from real disks, keep in mind that the disks are in good condition since the format used by BF are 43 tracks / 10 sectors per track (instead of 9) and this makes it more sensitive to load errors.
If you are having errors with disks, try different disks to discard this issue.

[tjjq44]

That's why I nearly never use 3" floppies, my old ones are randomly reliable...

[LambdaMikel]

Hi!
Today I tested BF on my 464 + dd1 + dkTronicks 64kb and it works fine (I have not tested it for more than 5 years :)When testing from real disks, keep in mind that the disks are in good condition since the format used by BF are 43 tracks / 10 sectors per track (instead of 9) and this makes it more sensitive to load errors.
If you are having errors with disks, try different disks to discard this issue.

Good to know it works flawlessly with a real DKtronics expansion - hence, it seems to be a good test for memory expansion that declare themselves as DKtronics substitutes.


I don't think it has anything to do with my disk drive or copying process, as the single DSK images also fail to load with HxC and DDI3. The only thing that works for me is the one DSK version with DDI3.


I will try another CPC 464 and see if I can load the single DSK versions there. Maybe there  is another difference between single DSK and one DSK version that makes it susceptible to loading errors. 


@rhino, can you think of anything else that would explain that?

[LambdaMikel]

That's why I nearly never use 3" floppies, my old ones are randomly reliable...

Mine are perfectly fine. 30 year old 3" disks, not a single one had any read or mechanical error. They are highly reliable.

[LambdaMikel]

Hi!
Today I tested BF on my 464 + dd1 + dkTronicks 64kb and it works fine (I have not tested it for more than 5 years :)When testing from real disks, keep in mind that the disks are in good condition since the format used by BF are 43 tracks / 10 sectors per track (instead of 9) and this makes it more sensitive to load errors.
If you are having errors with disks, try different disks to discard this issue.

Maybe DDI3 and/or HxC don't support that format? Because they also failed.