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General Category => Amstrad CPC hardware => Topic started by: LambdaMikel on 21:17, 30 September 18

Title: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 21:17, 30 September 18
Hi guys,

in the process of preparing a CPC 464 for sale, I also checked memory expansion with Zaxon's 4 MB, and with XMem, and again was extremely frustrated by both of these as only *1 out of 5 CPC 464s* is able to run through the Batman demo completely with them. 

I am sorry to say, but the modern memory expansions that are out there for sale don't work for the 464. They simply don't. It is unlikely that 4 out of 5 of my 464's have some defect (they are prefectly fine).

I tried dozends of different combinations - with and without DDI3 / M4 for disk, for the MX4 slot for XMem or 4 MB Piotr i tried various connections: with MotherX4, with LambdaBoard, with my Expansion Port expander that provides only one MX4 slot for the expansion, with different cable lengths, expansion ports were all cleaned with alcohol, etc.

Always, reliably, Batman Demo crashes sooner or later. I only own one CPC 464 for it run til the end (90 % chance).

This is very frustrating. Does anyone have a DKtronics 64 KB expansion for sale?

I am wondering if @revaldinho (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1776) RAM expansion will be ready at some point to better that situation somehow.

Best,

Michael

Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: GUNHED on 02:10, 01 October 18
The question is if the batman demo uses RAM configurations specific to the 6128? Maybe it's not intended to run on a 464? @Rhino (http://www.cpcwiki.eu/forum/index.php?action=profile;u=174) probably can tell us more.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: Audronic on 04:29, 01 October 18
@LambdaMikel (http://www.cpcwiki.eu/forum/index.php?action=profile;u=2172)


Could you drop a copy or a link to the demo that you are using Please


Thanks    Ray
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 05:31, 01 October 18
Quote from: GUNHED on 02:10, 01 October 18
The question is if the batman demo uses RAM configurations specific to the 6128? Maybe it's not intended to run on a 464? @Rhino (http://www.cpcwiki.eu/forum/index.php?action=profile;u=174) probably can tell us more.
Well it is working on one of my 464's, and fails on the other 4.... I can post a video at some point.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: rpalmer on 15:29, 01 October 18
Another question is does the batman demo need a specific CRTC to work properly?

Many external memory expansions for the 464/664 will not like working with mode #3 (note it should always be correctly referenced as mode #3 since the mode if defined ONLY by the lower 3 bits).
The basic issue is that on a 6128 the address lines A14/A15 go into a PAL and the outputs from the PAL select which bank 0 or 1 is referenced along with new A14/A15 address lines to the internal RAM whereas on an external memory expansion the remapped address is now a feedback scenario with the PAL which makes impossible to know if the address was remapped or not (see attached picture). How DK'Tronics overcome this problem I do not know, some say they abused RAMDIS signal.

rpalmer
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: GUNHED on 17:16, 01 October 18
Quote from: LambdaMikel on 05:31, 01 October 18
Well it is working on one of my 464's, and fails on the other 4.... I can post a video at some point.
Yes, that's understood, so there is a difference between these CPCs. Now, it may crash every time on a CPC464, but it's not fatal on one of them. Since I don't have that computer any longer I can't test. Time to move on to 6128  ;)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: GUNHED on 17:18, 01 October 18
Quote from: rpalmer on 15:29, 01 October 18
Many external memory expansions for the 464/664 will not like working with mode #3 (note it should always be correctly referenced as mode #3 since the mode if defined ONLY by the lower 3 bits).


Actually not. Therefore it's mode &C3.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 19:50, 01 October 18
The situation is still inconclusive. First, it is extremely difficult to get the adapters or cables set up such that the RAM expansion is working. With a short cable, even a little bit of PCB miss-alignment of the edge connector, it can result in totally different results when it comes to running Batman. As if the timing is, also from an electrical point of view, *extremely* delicate.  I don't know of any expansion where the contacts need to be aligned *perfectly* in order to work. DDI3 does not have that issue. Even how the cable bends can make a difference (because it puts different stress on the edge connector??? or is it signal relection and / or cross talk between lines?)

For 4 MB Piotr expansion and DDI3, using LambdaBoard and short cable, I usually have the siutation that I power up the 464, then run "disc for Batman demo. First thing it says that I have the wrong disk for my configuration (I am using the one disk version). This, however is a false alarm - after a reset with the reset button at the DDI3, next time I start Batman, it usually loads and runs. Now that already indicates to me that there is some bug in the CPLD or the decoding logic. There is some internal state which is not properly initialized or reset or whatever.

Now, depending on the CPC 464, with perfect cable setup, Batman usually runs to the Truecolor demo part. And this is where it crashes on most 464's.

I will report the exact configurations of the 464's for which Batman Demo runs through, and also the configurations for which it crashes. Maybe that helps in tracking this issue down.

Then, with XMem, there is a second set of behaviors. It usually does not report the "wrong configuration", and currently I cannot get it to continue to load after the setup screen at all. On all 464s. And this is extremely odd, because it used to be the case that Batman demo worked better with XMem than with 4 MB from Zaxon! For unknown reasons, this situation has swapped. XMem stopped working altogether for this currently. I am wondering if this related to to the ROM contents of XMem. I will clear and re-initialize and see if that makes a difference. But why should it?

So, the inconsistent and erratic behavior of these expansions indicates to me that something is fundamentally wrong. No offense, but it shouldn't be so difficult to get the 64 KB expansion running. This is really the most important part for a 464. I don't even care that much for the rest, but the 64 KB are kind of important to work flawlessly, and with all CPC 464 models.
So, the situation is inconclusive and frustrating, and something is wrong IMHO.


I should add that I tried this with Mother X4 also, with the diode removed, such that it can power the DDI3. That gives similar results in terms of success rate as with the LambdaBoard, but slightly lower because of longer signal paths it seems.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 19:53, 01 October 18
I would suggest to design an internal 464 64 KB DKtronics RAM expansion that connects directly to the Z80 socket in order to avoid the cable issues.

That issue kind of spawned my interest in memory expansions - maybe I'll try for myself if I can make a prototype RAM expansion that sheds some light on this.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 20:06, 01 October 18
Summing up: I can't recommend any of these RAM expansions for the 464 (I can't speak for the 6128 of course, as I have not done a lot of testing there). It is simply too difficult to set them up such that they work reliably, and even if they work, their behavior is frequently erratic. Now, if this is really caused by "bat programming"  ;)  in Batman I can't say, but I also had issues with other 128 KB demos. So I believe the fault is more on the expansion side than on the demo side.  No offense whatsoever of course, just trying to be as constructive criticism as possible. But it is very frustrating for sure.  And of course, there are probably games and applications for which they work flawlessly. Maybe I am a little bit too focused on the Batman demo... I am not saying that they are not useful, but I am saying that they are not working for certain use cases / applications / demos (at least not reliably). That's all.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: Rhino on 12:05, 02 October 18
The problem in the 464 with those memory expansions may be related to the #C3 mode, which is used in some effects of Batman Forever. It is possible that these expansions do not implement that memory mode correctly. I do not have them and I have not tested them, instead I have verified that 464 + DKTronics works fine.

About CRTC, BF is compatible with all types except type 2, and when it is detected, a message appears and the demo does not run.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: revaldinho on 12:57, 02 October 18
@LambdaMikel ,  you did ask about the state of my 464 RAM card and it's probably convenient to use this thread to talk about that, since the other thread was rather confusing given that the 6128 and 464 cards are very different things.


In my last update I had just sent off some new PCB designs to Seed. I had the boards back about a month ago and although I haven't spent much time on the cards in the meantime, I have assembled one and tested it briefly with my only 464 (an original high-key version). The good news is that it works better than my hacked proto but it's certainly not finished.


From the top of my head, the card passes all the RAM test programs I've found, it runs the DK'Tronics bank manager and silicon disk software; it runs the FutureOS GUI with the mouse pointer present and correct and no trail of debris (this being the board's main party trick of course); various games/demos all work including Hard Drivin', ChaseHQ, ZapTBall, Gryzor, Robocop, Prehistorik2 and R-Type. That's all good, as all of these games posed problems of one sort or another before I implemented the signal over-driving code. Seeing R-Type work is especially good as that did not work with my knifed and rewired proto which is otherwise very similar to the new card.


However, it's definitely not perfect. There are a few problem programs which I need to work through. I can boot to CP/M plus and run Wordstar and even edit, compile and run programs in Turbo Pascal but I get a 'Cannot load program' error on trying to run BBC BASIC. That's not right -  I was able to run BBC BASIC on the older proto when using just shadow memory, albeit with regular snow storms on screen - see the other thread.


Games-wise I only found problems with 2 games so far. Double-Dragon runs fine, but the graphics on the loading screens are garbage. Conversely P-47 has perfect loading screens but doesn't run the game at all - just a blank screen !


I would like to try Batman Forever, and particularly if it does use that mode C3, but unfortunately my 464 has the wrong type of CRTC which Batman detects and just announces 'CRTC Type 2 Not supported' before quitting.


As I said, I haven't spent a lot of time on this since the new cards came back, in fact hardly any time at all. That's partly because my attention has been diverted onto other projects and partly because I had kind of assumed that all the other RAM cards around were already pretty robust on the 464. I was surprised to read about the number of issues you raised as I was thinking that my board's only really USP was the support for the mode C3, for which there might only be a limited interest.


I will try to make a bit more time for this over the next couple of weeks. Sounds like I should get on and extract my CRTC and replace it with a socket so I can have a go at Batman Forever. I don't know if the P-47/Double Dragon issues might be CRTC related too but that would definitely let me eliminate it from my enquiries.


My latest code isn't on GitHub yet. I have a new version which supports the new DIP switches to control over-driving and shadow memory modes which should let the card be used with 6128s as well as 464/664s ... but the new code isn't fully tested on anything yet. I'll upload it once I've done some more testing and have a clear status on the different machines/modes to report even if that's not a perfect bill of health.


If you have the ability to upload new JEDEC files to the CPLD (XC9536 or XC9572) then I could build up another board and let you have one for testing with your CPC farm. Sounds like it would be very important to test with as many different 464 motherboard types as possible. I think you could say we're still in the alpha phase here and I'd like to get a bit further before opening up beta testing to many more people.


BTW if anyone in the Bristol UK area has a 464 or 2 I could borrow to test with some other motherboard types that would be very helpful indeed.


R
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: GUNHED on 13:37, 02 October 18
Even if I don't have a CPC464 (any longer) it's wonderful that you make this great expansion eventually implementing RAM mode &C3 to the 464 - Well, a dream comes true!  ;)  So please keep your great work going!  :)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 19:46, 02 October 18
Does nobody have the schematics and PAL code of the DKtronics 64 KB mem expansion? Maybe we can learn from there how it is done "the right way"?


Now, that kind of presupposes that the Batman demo works flawlessly all of the time 100 % on all different CPC models with the right CRTCs... @Rhino (http://www.cpcwiki.eu/forum/index.php?action=profile;u=174) you said it would work with the 464 and DKtronics, but how extensively have you tested that? Maybe that demo crashes also with the original DKtronics 64 expansion on certain CPCs?
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 19:52, 02 October 18
Quote from: revaldinho on 12:57, 02 October 18
I would like to try Batman Forever, and particularly if it does use that mode C3, but unfortunately my 464 has the wrong type of CRTC which Batman detects and just announces 'CRTC Type 2 Not supported' before quitting.

I would send you one, but the only spare 464 board I currently have also has the wrong CRTC unfortunately  >:(

Quote from: revaldinho on 12:57, 02 October 18If you have the ability to upload new JEDEC files to the CPLD (XC9536 or XC9572) then I could build up another board and let you have one for testing with your CPC farm. Sounds like it would be very important to test with as many different 464 motherboard types as possible. I think you could say we're still in the alpha phase here and I'd like to get a bit further before opening up beta testing to many more people.


I am able to flash these CPLDs as I am using them for my own work. More than happy to help with my "464 farm"! Let me know  :) 
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: revaldinho on 23:59, 02 October 18
@LambdaMikel (http://www.cpcwiki.eu/forum/index.php?action=profile;u=2172) - OK I'll take you up on that. If I build and ship you a board at the weekend you can try it out on your 464's and I'll hold off on extracting my own CPC464's CRTC 'til you've had a go. Probably not the best idea for me to risk damage to my only 464 at this point. I'll PM you.



Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: tjjq44 on 11:19, 03 October 18
Hi,

I've been looking for an expansion memory to fit my 464 for a long time! Being "fully dk'tronics compatible" is an absolute need for me since I want to be able to run actual and old 128k software and demos.

I could buy a used 64k or 256k dk'tronics expansion but currently they are very rare and when one comes on sale, its price is outrageous, more than a new one back in 1985, even more expensive than an actual used cpc 664!!!! Apple 1 excepted, it's the first time I see a used electronic product exceed the price when it was launched  :o !?!?!?!

@revaldinho: Hope you will succeed in making this dream come true! When you'll get it finalized, I'll be interested to buy one (I can solder components by myself but sourcing them may be a little bit complicated where I live in France) and test it thoroughly on my 464s (I own 3 of them) and maybe if I'm confident enough on my 664* ;-) I also have a UM6845R (crtc 1) spare chip I can send to you if you need.


*This 664 was in fact my cousin's one when he was young. He used it from 1985 to 1991 or so. And I used it a lot when I was on vacation at my aunt's in the mid 90's. When she moved in the late 90's, she asked my cousin what to do of his old computer, he answered: ask Thomas, he might be interested... Yes I am !!!  :D  
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: GUNHED on 16:21, 03 October 18
Wouldn't it be better so day 'Amstrad Compatible', which means to be compatible to the way the 6128 does manage his expansion RAM? I would say yes, because we should at first stay compatible to the producer of the CPC. The dk'tronics for the CPC464 can not (as far as I know) provide RAM mode &C3 in the same way the CPC6128 does.  :)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: tjjq44 on 18:59, 03 October 18
Quote from: GUNHED on 16:21, 03 October 18
The dk'tronics for the CPC464 can not (as far as I know) provide RAM mode &C3 in the same way the CPC6128 does.  :)


I know that! And no 464 memory expansion will do. The only way to afford it is to modify the 464 logicboard what I refuse!


dk'tronics is still today the most compatible cpc 464 expansion but costly, hope revaldinho will succeed in his project
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: tjjq44 on 11:38, 04 October 18
After digging the web for a few days, I found that:

https://www.sellmyretro.com/offer/details/ram-expansion-512-kb-for-amstrad-464~~6128-29065

The site says "DKTronic compatibile", I have some doubts concerning the 464 but I let me go for an order, £30 isn't a so big deal!

Never seen this expansion elsewhere, don't know if it is based on some project already known on the web... I'll test it and feedback my opinions ;-)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: tjjq44 on 13:10, 04 October 18
Quote from: tjjq44 on 11:38, 04 October 18
Never seen this expansion elsewhere


In fact it is Zaxon's 512k memory expansion, seems LambdaMikel had problems with his 4MB one, hope this one will be more 464 compliant ;-)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 16:46, 04 October 18
Quote from: tjjq44 on 11:38, 04 October 18
After digging the web for a few days, I found that:

https://www.sellmyretro.com/offer/details/ram-expansion-512-kb-for-amstrad-464~~6128-29065 (https://www.sellmyretro.com/offer/details/ram-expansion-512-kb-for-amstrad-464~~6128-29065)

The site says "DKTronic compatibile", I have some doubts concerning the 464 but I let me go for an order, £30 isn't a so big deal!

Never seen this expansion elsewhere, don't know if it is based on some project already known on the web... I'll test it and feedback my opinions ;-)
Well, I had that expanion before i went for Piotr's / Zaxon 4 MB expansion, which is being discussed here... I traded it in for the 4 MB one. AFAIK, the switch on the 4 MB mem expansion that we are discussing here if for DKtronics mode on / off.

In my experience, the 512 KB expansion suffers from exactly the same problems as the 4 MB version from the same developers.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: Vyper68 on 16:52, 04 October 18
I have one of Piotr's expansions, I bought it a couple of weeks ago. There is a switch on the top for 464/6128 operation so bear that in mind. The RAM check passed when I tested it on my 464 but I haven't tried BATMAN.
I Can only use my M4 as I don't have a DDI3 anymore - so I'll give it a go.. If anyone want's me to test something with my 464 just ask.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 17:01, 04 October 18
Quote from: tjjq44 on 13:10, 04 October 18

In fact it is Zaxon's 512k memory expansion, seems LambdaMikel had problems with his 4MB one, hope this one will be more 464 compliant ;-)
Well, give it a try - in my experience, it works on some CPC 464's, and fails on others. As I said, I had it before and turned it in when he came out with the 4 MB version. And more memory wasn't the only reason for turning it in  :) I also exchanged the 4 MB version once, and the second one I currently have is doing a lot better than the first one, but there are still issues with it which are being discussed in this thread.

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/ (http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/4mb-externial-ram-expansion-will-be-soon/100/)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: Vyper68 on 17:13, 04 October 18
Quote from: LambdaMikel on 17:01, 04 October 18
Well, give it a try - in my experience, it works on some CPC 464's, and fails on others. As I said, I had it before and turned it in when he came out with the 4 MB version. And more memory wasn't the only reason for turning it in  :) I also exchanged the 4 MB version once, and the second one I currently have is doing a lot better than the first one, but there are still issues with it which are being discussed in this thread.

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/ (http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/4mb-externial-ram-expansion-will-be-soon/100/)
Yeah I remember reading that at the time. I thought he pulled them off sale because of the problems ???
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 17:19, 04 October 18
Quote from: Vyper68 on 17:13, 04 October 18
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.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: tjjq44 on 17:28, 04 October 18
Quote from: LambdaMikel on 17:01, 04 October 18
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/ (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...

Quote from: LambdaMikel on 17:19, 04 October 18The 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...



Quote from: LambdaMikel on 17:19, 04 October 18
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  :)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: Vyper68 on 17:31, 04 October 18
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.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 17:32, 04 October 18
Quote from: tjjq44 on 17:28, 04 October 18
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 (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/
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: Vyper68 on 17:33, 04 October 18
Quote from: tjjq44 on 17:28, 04 October 18


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.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 17:33, 04 October 18
Quote from: tjjq44 on 17:28, 04 October 18
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.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: tjjq44 on 17:36, 04 October 18
Encouraging...  :(
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: Vyper68 on 17:36, 04 October 18
Quote from: tjjq44 on 17:28, 04 October 18

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.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: Vyper68 on 17:38, 04 October 18
Quote from: LambdaMikel on 17:33, 04 October 18
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.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: tjjq44 on 17:41, 04 October 18

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 :D
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 18:23, 04 October 18
Quote from: Vyper68 on 17:31, 04 October 18
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?
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: Vyper68 on 20:13, 04 October 18
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.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 20:37, 04 October 18
Quote from: Vyper68 on 20:13, 04 October 18
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

Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: tjjq44 on 21:29, 04 October 18
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  :D


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.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 22:59, 04 October 18
Quote from: tjjq44 on 21:29, 04 October 18
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.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 08:58, 05 October 18
Quote from: Vyper68 on 20:13, 04 October 18
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 (http://www.cpcwiki.eu/forum/index.php?action=profile;u=174)  - 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 (https://files.scene.org/view/parties/2011/forever11/cpc/demo/batman_forever.zip)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: tjjq44 on 11:48, 05 October 18
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 :

(http://tjjq.free.fr/cpc/batman-cat.jpg)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: tjjq44 on 12:19, 05 October 18
Just tried on my 664 and it doesn't launch (of course)... nevertheless I get a message on the screen ;-)

(http://tjjq.free.fr/cpc/batman-664.jpg)

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?
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: Duke on 14:40, 05 October 18
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.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 17:10, 05 October 18
Quote from: tjjq44 on 12:19, 05 October 18You 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/ (http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/'modern'-way-of-creating-physical-3'-disks/)(picture at the end)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: Rhino on 18:00, 05 October 18
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.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: tjjq44 on 18:41, 05 October 18
That's why I nearly never use 3" floppies, my old ones are randomly reliable...
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 19:11, 05 October 18
Quote from: Rhino on 18:00, 05 October 18
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?
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 19:12, 05 October 18
Quote from: tjjq44 on 18:41, 05 October 18
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.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 19:13, 05 October 18
Quote from: Rhino on 18:00, 05 October 18
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.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 19:16, 05 October 18
Quote from: Duke on 14:40, 05 October 18
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.


At some point, I had XMem working with Batman demo. Currently, it had stopped working altogether. Maybe it is defect by now. But I also used a different 464. I will pull out the 464 with worked fine with XMem and see if I can reproduce the successful running of Batman that I had back then here with XMem and that 464:

http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/4mb-externial-ram-expansion-will-be-soon/100/ (http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/4mb-externial-ram-expansion-will-be-soon/100/)


Reading through my old post - what cracks me up is that I wrote

All of these 5 CPCs work perfectly fine with Batman Demo with XMem. 

That should also include the current CPC I am using. I am really clueless.
I think XMem has been damaged somehow.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: revaldinho on 00:33, 07 October 18
@LambdaMikel (http://www.cpcwiki.eu/forum/index.php?action=profile;u=2172) - I've sent you a PM to arrange getting one of my cards to you.


I have done some testing today using my card with a 464 and also a couple of 6128s and things are looking actually more advanced than I thought.


Of the programs I reported some trouble with, it turns out that I have similar problems with at least one of the 6128s so these are not necessarily RAM card related issues at all. The Double-Dragon on screen garbage in the loading phase is a CRTC issue - both my 464 and a 6128 with a type 2 CRTC show this while the other 6128 (which has a type 0 CRTC and  _can_ run Batman Forever) does not. I have another image of Alien-8 which only works on the type 0 CRTC as well. None of the machines can run my P47 disk image. Is that a Plus only game ? Or a duff disk image maybe? Also potentially a duff image is my BBC BASIC CP/M one. That fails to run on any of the machines so also doesn't looks like a RAM card related image. I tried making a new version but again none of the machines like it even when running a stock 6128 booting CP/M from floppy.


All the other stuff I reported working is still working with the latest code, and on top of that the Phortem demo runs fine also. All of these work well even with the RAM card voltage turned down to 4.5V.


Let's not get too carried away though - this is all on my scientifically and statistically suspect sample of one CPC464.


Let's see how @LambdaMikel (http://www.cpcwiki.eu/forum/index.php?action=profile;u=2172) 's CPC farm gets on with the card before thinking of letting more samples into the wild.


R.



Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: Duke on 10:27, 07 October 18
Put together a little extended ram tester (for first 512KB only, for now).
It will test regular banking mode, C1 mode and C3 mode.
Will add C2 mode later.

Maybe useful to check various expansions.

Instructions:
RUN"RAM512KB

EDIT: Updated to v1.0.1 - now checks if upper ROM in C3 mode is messing with 0x4000.
EDIT2: Messy source code if anyone is interested -> https://github.com/M4Duke/z80/blob/master/RAM512KB.s
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: revaldinho on 12:57, 07 October 18
Brilliant. That's great Duke and particularly the updated v1.0.1


Running on my 464 card with the overdrive and shadow modes turned on the test correctly identifies the card as a 448KB expansion (remember that I have to give up a 64K bank for the shadow mode) and it passes all of the tests including the C3 mode.


With the shadow mode turned off the 464 card is instead a 512KB card and should work like all the others. In this case it passes all the tests except for the C3 mode where I see the message 'rom remapped 0x4000!' on all banks except the last one. The last one says 'bank 3 no base ram remap! - rom remapped 0x4000!'


I've attached the screen shots

-P1130703.jpg is the 464 with overdrive ON, shadow mode OFF
-P1130704.jog is the 464 with overdrive ON, shadow mode ON, shadow bank set to 7

R



Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 18:43, 07 October 18
@Duke (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1624) , great, thansk for making the test!I have problem running it though - please see screenshots and correct any errors.
EDIT: looking at the Z80 I also tried load and call &8000, which gives me a black screen.

Tried with 2 diffferent CPCs, and 2 different cable connectins. You can see the XMem is detected (firmware message).
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: Duke on 18:59, 07 October 18
Quote from: LambdaMikel on 18:43, 07 October 18
@Duke (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1624) , great, thansk for making the test!I have problem running it though - please see screenshots and correct any errors.
EDIT: looking at the Z80 I also tried load and call &8000, which gives me a black screen.

Weird stuff, it works on my 464, when using M4 to run the file. I attached a .DSK here just incase. It works fine with WinApe too.

@revaldinho (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1776)
Notice the "Rom remap 0x4000!" error, could also be another error with the area at 0x4000 - 0x7FFF mapping. More checking needed.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: revaldinho on 19:17, 07 October 18
@Duke (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1624)
Quote from: Duke on 18:59, 07 October 18
Notice the "Rom remap 0x4000!" error, could also be another error with the area at 0x4000 - 0x7FFF mapping. More checking needed.


On the run with shadow RAM enabled, I get no errors at all.


I was expecting to see errors without the shadow RAM enabled in mode C3 because my card then just overdrives address bit 15 to remap 0x4000-0x7FFF to 0xC000-0xFFFF, which will result in reading data back from ROMs if enabled. (This is what causes the trail of debris in the FutureOS GUI on all other cards). So, is this message indicating something other than that ?


Can someone share a screenshot of what it looks like on any of the other cards ?


R

Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: Duke on 19:23, 07 October 18
Quote from: revaldinho on 19:17, 07 October 18
On the run with shadow RAM enabled, I get no errors at all.

I was expecting to see errors without the shadow RAM enabled in mode C3 because my card then just overdrives address bit 15 to remap 0x4000-0x7FFF to 0xC000-0xFFFF, which will result in reading data back from ROMs if enabled. (This is what causes the trail of debris in the FutureOS GUI on all other cards). So, is this message indicating something other than that ?
Yes, it seems the shadow RAM one is working as it should (similar to 6128). Which is cool.

And the error message would be correct in your second test with the overdrive, just stating it as I realized other mapping errors could result in same message, as I don't check if it's ROM data, just if it's base RAM data normally at 0xC000 when mapping upper rom 0 ontop of C3 mode.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: revaldinho on 19:40, 07 October 18
Thanks Duke


Aha, that all sounds good then.


I would hope that all the overdrive only cards report the same messages...


The only one I didn't understand was why I got the message ''Page07, bank 03 no base ram remap! - rom remapped 0x4000!'  which was different to the others. I don't see anything in the CPLD code that would make that bank any different when not in shadow mode.

Very handy to have your test - it's one of the ones at the top of my long list of things to run now when updating the CPLD code now. That + the test.bin which I downloaded from a link in the forum somewhere + FutureOS GUI + Phortem seem to flush out almost everything.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: Duke on 19:48, 07 October 18
Quote from: revaldinho on 19:40, 07 October 18
The only one I didn't understand was why I got the message ''Page07, bank 03 no base ram remap! - rom remapped 0x4000!'  which was different to the others. I don't see anything in the CPLD code that would make that bank any different when not in shadow mode.

Maybe I have some bug in the code, will re-check it all later, but it should mean that 0xC000 in base ram is not present at 0x4000 when in C3 mode.

Here is the result of XMEM on a 464. All ok, except in C3 mode as expected with the upper-rom showing at 0x4000, similar to "dk'tronics" C3 mode.

Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: revaldinho on 21:02, 07 October 18
And another thing !  :D


Buoyed up with a bit more confidence after passing Duke's new test and seeing a lot of other issues fall away I finally tackled the CP/M plus BBC BASIC problem again.


Definitely a disk image issue. I don't know what happened to that .dsk, but after deleting it and recreating afresh I can now run BBC BASIC on my 464 again. You might remember from the other thread that I did manage to run it previously on my original non-overdriving card, but only with frequent, if mild video snowstorms.  It works much better now both in overdrive-only and overdrive + shadow modes on the revised card - snap attached.


HIMEM is 60928, which is surely enough.


R


PS @LambdaMikel (http://www.cpcwiki.eu/forum/index.php?action=profile;u=2172) - I have made up and tested a second board for you to test, so just a reminder that you'll need to let me know where to post it.




Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 21:09, 07 October 18
@Duke (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1624)  thanks for the DSK - I have no idea what went wrong with that DSK creation process! I added AMSDOS headers etc., it seems there is some weird bug in DSKtool.jar??? Anyhow. Was able to load now.

It indeed seems that most of my issues are cable reliabilty issues. After fiddeling with your test with Piotr expansion, I made sure it would pass all OK, then ran Batman, and it worked - that means, it got through the "truecolor" demo! That usually crashes. After all, 4 MB Piotr seems to be working fine now on this one 464. I can test others as well.

I will prepare a Lambdaboard where 4 MB Piotr is soldered in permanetly.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 21:12, 07 October 18
XMem also passes the test now (I reseated all the chips... that seems to have made a difference) I am getting this:

Batman either crashes or blank screen after loader.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 21:15, 07 October 18
Quote from: revaldinho on 00:33, 07 October 18
@LambdaMikel (http://www.cpcwiki.eu/forum/index.php?action=profile;u=2172) - I've sent you a PM to arrange getting one of my cards to you.

Let's see how @LambdaMikel (http://www.cpcwiki.eu/forum/index.php?action=profile;u=2172) 's CPC farm gets on with the card before thinking of letting more samples into the wild.


R.
Thank @revaldinho (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1776) !
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 21:48, 07 October 18
So here is the situation mentioned earlier, that Batman (or 4 MB Piotr) needs a reset sometimes.
Works then. And even goes through truecolor currently.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 21:50, 07 October 18
And here are some tests with *ZMem*.
Batman either hangs after load screen or crashes with pixels, same as with XMem.

Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 22:59, 07 October 18
So it seems that currently I have at least have 2 CPC 464 that work with Piotr 4 MB (Batman)... XMem and ZMem couldn't reactivate yet (ROM of XMem works fine)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 05:18, 08 October 18
So, it seems that @Duke (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1624) 's test is not "strong / conclusive enough" in order to understand why XMem is not running Batman, right?
It seems everything looks fine in the test, yet Batman doesn't work. Unlike 4 MB Piotr, which is perfectly fine now.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: Duke on 10:14, 08 October 18
Quote from: LambdaMikel on 05:18, 08 October 18
So, it seems that @Duke (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1624) 's test is not "strong / conclusive enough" in order to understand why XMem is not running Batman, right?
It seems everything looks fine in the test, yet Batman doesn't work. Unlike 4 MB Piotr, which is perfectly fine now.
Actually the error message you got for XMEM in C3 mode, indicates that the "464 / 6128" switch on the XMEM is set to 6128.
I can see it is not, maybe the switch does not work properly anymore?
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 17:22, 08 October 18
@Duke (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1624)  - Interesting!! Let me check that and report back...
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 06:20, 09 October 18
Quote from: LambdaMikel on 17:22, 08 October 18
@Duke (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1624)  - Interesting!! Let me check that and report back...
No, the switch is fine. Measured it (continuity tester). Maybe the CPLD is f****ed by now.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: revaldinho on 22:13, 10 October 18


I've posted off a board for @LambdaMikel (http://www.cpcwiki.eu/forum/index.php?action=profile;u=2172) to test earlier this week.


So, mainly for his benefit but also for anyone else interested, there is a PDF of release notes to go with that (mainly important for getting the DIP switch setting right) in GitHub here:

https://github.com/revaldinho/cpc_ram_expansion/blob/master/cpc_ram_expansion/releases/rc-2-bulldog/Revaldinho_512K_RAM_RC-2-BUlldog_Release_notes.pdf (https://github.com/revaldinho/cpc_ram_expansion/blob/master/cpc_ram_expansion/releases/rc-2-bulldog/Revaldinho_512K_RAM_RC-2-BUlldog_Release_notes.pdf)

And here is a link to a Google Sheet of testing results with this particular cut of the CPLD code

https://docs.google.com/spreadsheets/d/11wxhIDWy2wNmKSXZwBqjqQjMN2nNZDtILEvy6_GrM8I/edit?usp=sharing

All looks good on my CPC464 and a couple of 6128s to date I have to say, although with the various issues and behaviours reported across different motherboard types in this thread, I await @LambdaMikel (http://www.cpcwiki.eu/forum/index.php?action=profile;u=2172) 's test results with a bit of trepidation.


One slightly amusing aside in the meantime, I was also able to test the full shadow mode (where the shadow bank services all CPC Base RAM reads other than those done by the video circuitry) using @gerald (http://www.cpcwiki.eu/forum/index.php?action=profile;u=250) 's RamTest ROM with no problems. So, I think that the card has the miraculous and unintended property of being able to revive dead CPC464s if they are suffering from faulty base RAM ! Of course if the memory fault is in a video RAM area then that'll show up as on-screen corruption, but otherwise I think this must be true. Let's see.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: GUNHED on 13:13, 11 October 18
Great results!  :) :) :)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 09:27, 13 October 18
Quote from: revaldinho on 22:13, 10 October 18

I've posted off a board for @LambdaMikel (http://www.cpcwiki.eu/forum/index.php?action=profile;u=2172) to test earlier this week....
So, I think that the card has the miraculous and unintended property of being able to revive dead CPC464s if they are suffering from faulty base RAM !
So looking forward to checking your board out, @revaldinho (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1776)  !!  And I can even try FutureOS on the 464 then it seems  :) However, you should reconsider the name - you should have called it Lazarus for obvious reasons  :laugh:
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: revaldinho on 11:33, 13 October 18
Quote from: LambdaMikel on 09:27, 13 October 18
So looking forward to checking your board out, @revaldinho (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1776)  !!  And I can even try FutureOS on the 464 then it seems  :) However, you should reconsider the name - you should have called it Lazarus for obvious reasons  :laugh:


I still have my fingers crossed given I've only been able to test with one CPC464 motherboard so far. It's not a scientifically huge sample.


I did some additional tests this week running the card from the CPC power supply rather than an external bench supply. Got a bit of a surprise when I put my voltmeter on the power rails and measured only 4.45V! OK, there was a DDI-3 and a couple of ROM cards hanging off the back of the machine too, but that was quite a bit lower than I'd expected. Still, no cause for alarm. All still working.  I think I should probably lower the voltage on my lab PSU for more tests though.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: Rhino on 12:56, 13 October 18
Quote from: LambdaMikel on 21:48, 07 October 18
So here is the situation mentioned earlier, that Batman (or 4 MB Piotr) needs a reset sometimes.
Works then. And even goes through truecolor currently.
The "wrong disk" message is not related to a memory issue but to a drive/disk problem, for example, if you try the 3.5" dsk on a single sided drive.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 09:21, 15 October 18
@revaldinho (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1776)  the mem expansion has arrived!! It looks *great*!
Will start checking it out soon. 


Cheers
Michael
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 10:07, 16 October 18
Some good and some bad news so far - Batman demo successfully passed the TrueColor test on 464 #1.
Unfortunately, it crashed later. Will take a picture and run again.
@revaldinho (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1776)  I haven't studied and changed the jumper settings yet, this is only a first run. Late now, but will do more runs tomorrow.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 10:22, 16 October 18
@revaldinho (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1776)  congratulations, your mem expansion ran through the finish line!  8) More tests tomorrow.


Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 04:16, 22 October 18
The contestants - CPC 1 - CPC 4. 
They are all CRTC 0 (3 Hitachi and 1 UM).
CPC 3 is 40007, the others are 40010s.


Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 08:04, 26 October 18
FutureOS works (no Cursor corruption), but I cannot see the contents of the drive - DDI3 "A / DIR" just seems to hang.

Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: GUNHED on 18:38, 26 October 18
Again congratulations to this fine piece of hardware.  :)

[ot]Can somebody please verify / check the functionality of the DDI3 under FutureOS? Well I don't want to derail this thread, you could answer in the 'FutureOS corner' thread if you like. [/ot]
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: revaldinho on 22:34, 26 October 18
Quote from: GUNHED on 18:38, 26 October 18

[ot]Can somebody please verify / check the functionality of the DDI3 under FutureOS? Well I don't want to derail this thread, you could answer in the 'FutureOS corner' thread if you like. [/ot]


It is great to see the C3 mode working on @LambdaMikel (http://www.cpcwiki.eu/forum/index.php?action=profile;u=2172) 's machines too. We have a fair few combinations of motherboards/gate array types/CRTC type between us and generally things are looking good so far ... (hopefully not famous last words).  :D


On the Future OS/DDI-3 issue, we've run a couple of different combinations each now and this is what we see:




Machine      Lower ROM   RAM Card    Future OS Result
CPC 464-LM   464 F/ware  Zaxon 4MB   ROM2-5    DDI-3 hang
CPC 464-RE   FOS low ROM Revaldinho  ROM10-13  DDI-3 hang
CPC 464-LM   464 F/ware  Revaldinho  ROM2-5    DDI-3 hang
CPC 464-RE   6128 F/ware Revaldinho  ROM10-13  DDI-3 fully working, also Gotek on drive B (via DDI-3 B connector)



.. so it looks very much as though FutureOS doesn't work with the DDI-3 unless you also do the 6128 lower ROM replacement doesn't it ?


I'm going to ship LambdaMikel one of my SixROM boards after the weekend with the same configuration I have working on mine (6128 lowrom/BASIC replacement + the FOS ROMs in slots 10-13). Hopefully that will be good on his collection too and close this issue off.




R
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 01:46, 28 October 18
It is a DDI-3 problem - tested it with DDI-1 / DD1 and works prefectly fine!



Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: GUNHED on 18:37, 30 October 18
Quote from: revaldinho on 22:34, 26 October 18
.. so it looks very much as though FutureOS doesn't work with the DDI-3 unless you also do the 6128 lower ROM replacement doesn't it ?


Thanks a lot for testing. The result makes no sense since FutureOS doesn't use the lower ROM or anything else than it's own code. Clearly a DDI3 problem. However, great to see the RAM mode &C3 on different 464's confirmed.  :)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 06:34, 01 November 18
Right, it is strange. Works fine with DDI-1 and HxC.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 06:38, 01 November 18
Gunhead's "Tribute to the sisters" FutureOS Game runs fine on the 464 in C3 mode!
Great game, btw - awesome playability (scrolling!!), music and graphics.  :)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: GUNHED on 00:54, 02 November 18
Thank's a lot!  :) :) :)  Still there is this hard-to-find-bug... but that's the fun in coding ;-)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 04:50, 03 November 18
OK, so I made some stupid mistake when I copied the DSK / HFE file to the DDI-3.
FutureOS is working fine with DDI-3 - it does NOT need the CPC 6128 Firmware / Lower ROMs.  :)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: revaldinho on 00:57, 05 December 18

It has been quite a while since I posted about progress on my RAM card, so you would be forgiven if you thought it had disappeared down the back of the sofa with all those other unfinished projects. In fact the opposite is true and I, or more accurately we, have spent quite a lot of time testing and tweaking and testing again over the last couple of months. I didn't want to post an update until we reached the point at which I'd be happy to distribute cards a little more widely. And that's where we are now.


Before the update, I  have to say a big thank you to @LambdaMikel (http://www.cpcwiki.eu/forum/index.php?action=profile;u=2172)  and @Duke (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1624)  for their encouragement and active assistance. LM has spent a lot of time and effort on testing a couple of different CPLD versions of this card for me with his extensive collection of Schneider CPC464s. Duke has been very helpful with technical information about the M4 card and even provided a card at short notice for debug when we came across an issue (now resolved) between the RAM and M4 cards. Duke has also done some compatibility testing on late model machines to which LM and I didn't have access. Thank you both very much and indeed thanks also to @Rennert (http://www.cpcwiki.eu/forum/index.php?action=profile;u=992)  for some additional test results on his KC Compact system. It has been invaluable having so much additional input and access to a wide range of different CPC computers as test environments.


So let's start off with a brief recap of what the card is for anyone late to the thread.


Card Summary


This is 512KByte memory expansion card which is suitable for all Amstrad CPC computers.


The card has an MX4 type connector, so requires an expansion board such as the Mother X4, Revaldinho backplane, LambdaBoard or just a suitable ribbon cable connection to hook up to the computer.


Adding RAM to a 6128 class machine is pretty unremarkable and in this respect the card behaves very much like any others, including my super cheap Old School DIY card (http://www.cpcwiki.eu/index.php/Old_School_512K_RAM_Expansion). Adding RAM to the older 464 & 664 computers is much more problematic and many of the RAM card features and most of the design effort has been specific to these machines.


Like other RAM cards, this one provides full DK'Tronics compatibility when used with CPC464/664 computers. This is sufficient to run the vast majority of software requiring additional RAM including CP/M Plus, demos such as Phortem and Batman Forever and many games.


However, this card also provides a unique 'shadow mode' which enables perfect Amstrad CPC6128 video mode C3 operation on CPC464/664 computers. In shadow mode these older machines can now run FutureOS and other software relying on this video mode and which previously would run only on 6128s. This ability is not provided by any other RAM cards at this time.


Shadow mode can also enable a 464/664 to run entirely from the card RAM without using base RAM other than for the video display. This may be useful for reviving or at least diagnosing CPC464s with faulty internal RAM.


The 512KB RAM can be configured to appear at either IO port &7Fxx or &7Exx, allowing two cards to be used together for a full 1MByte expansion. Compatibility with X-MEM/Y-MEM as additional RAM is a possibility here too.


Testing Status


As part of the main test and verification effort  we have tested multiple RAM cards on different combinations of CPC main boards and components including
Cards have been tested using different expansion boards shared with other peripherals
A standard test suite has been used made up of
All tests have been run either using power from the CPC +5V edge connector pin or a 4.5V bench supply.


Selected tests have been swept across voltage from 4.35V to 5.5V.


A Google Sheet of test results for different firmware versions can be viewed here:


https://docs.google.com/spreadsheets/d/19l64P-N8vimZZS3KhymiAu7SFn6GN82VnODVBNmlvfc/edit?usp=sharing (https://docs.google.com/spreadsheets/d/19l64P-N8vimZZS3KhymiAu7SFn6GN82VnODVBNmlvfc/edit?usp=sharing)


Some additional basic compatibility testing has also been done with the following machines
Compatibility


The following table sets out the basic  RAM card configurations required and compatibility achieved with different CPC motherboards.



                Standard Setting        Overdrive Setting    Overdrive/Shadow Setting
                Exp. C3 Mode Exp. C3 Mode      Exp.    C3 Mode
CPC464         NA NA         512K DK'T      448K    Amstrad
CPC664         NA NA         512K DK'T      448K    Amstrad
CPC464 [ASIC] 512K     DK'T         NA NA      NA      NA
CPC464 Plus 512K DK'T/Amstrad NA NA      NA      NA
CPC6128 Plus 512K Amstrad NA NA      NA      NA

KC Compact      512K     DK'T           NA      NA           NA      NA



RAM expansion modes C0-C2 and C4-C7 work identically across all supported machines. Only the special C3 mode (requiring remapping of base memory) behaviour differs from one model to another.


On all machines the card will provide a 512KB expansion with either DK'Tronics or Amstrad C3 mode operation.


Perfect Amstrad C3 mode operation is available on all machines other than the very late CPC464 costdown revision (ASIC in place of earlier gate arrays) and the KC Compact. These machines will still get a 512KByte expansion but are limited to the DK'Tronics type C3 mode. 


By default a CPC464 Plus will also get a DK'Tronics C3 mode unless a resistor is added to the motherboard. The CPC464 Plus and CPC6128Plus motherboards are identical and this resistor is a factory option component which distinguishes between the two. It is included in the CPC6128 Plus but omitted from the CPC464 Plus builds and is needed to configure the ASIC for the additional RAM banks and enable the C3 mode RAM remapping. 

When using the CPC464/664 in shadow mode the effective capacity of the card is reduced by 64K to accommodate shadowing of base memory.


Documentation


More documentation including DIP switch settings and technical information is available in the release notes for the current CPLD Build:


https://github.com/revaldinho/cpc_ram_expansion/blob/master/cpc_ram_expansion/releases/rc-5-elephant/CPC_Universal_512K_Ram_Expansion_RC-5-Elephant_Release_Notes.pdf (https://github.com/revaldinho/cpc_ram_expansion/blob/master/cpc_ram_expansion/releases/rc-5-elephant/CPC_Universal_512K_Ram_Expansion_RC-5-Elephant_Release_Notes.pdf)


Licensing and Source Code


As usual all source code for the project, including CPLD Verilog code, makefiles and PCB layout files, is available on GitHub (https://github.com/revaldinho/cpc_ram_expansion/tree/master/cpc_ram_expansion) under the GPL3 license (https://github.com/revaldinho/cpc_ram_expansion/blob/master/LICENSE).


Early Release Cards


Although testing to date has been pretty thorough, it hasn't been possible to test every single combination of core components (CPU/GA/CRTC) on every CPC main board type.  So before declaring the cards finished, I would like to make a small number of cards available for other users to try.


I have enough components to assemble around a dozen cards initially. If you're interested in getting hold of one of these early release cards then please send me a PM including your email address and postal address if you are placing a firm order.


Costs for this first batch of cards will be as follows.



                Standard   Tracked &
                Economy    Signed For
UK         £26.00    £31.00
Europe         £27.00    £32.00
Worldwide £28.00    £33.00



A  certificate of posting will be obtained for all packages, but I recommend the tracked and signed for option to minimize the chances of anything going astray.


Payment will be via PayPal, for which I'll email out invoices prior to assembly of your card.


The board is compatible with Mother X4 and other expansion systems,  but if you don't already have something suitable then I can supply limited numbers of my own expansion backplane and ribbon cables connectors too. Let me know with your PM.


Rev.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 02:47, 05 December 18
Fantastic!! A dream come true!!  :D 
Happy I could contribute to the testing effort.
Really great work!!!  :)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: GUNHED on 15:35, 05 December 18
Quote from: revaldinho on 00:57, 05 December 18
However, this card also provides a unique 'shadow mode' which enables perfect Amstrad CPC6128 video mode C3 operation on CPC464/664 computers. In shadow mode these older machines can now run FutureOS and other software relying on this video mode and which previously would run only on 6128s. This ability is not provided by any other RAM cards at this time.


Thank you for this super awesome X-Mas present!  :) :) :) :) :) :) :)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 01:11, 06 December 18
... now everybody is going to buy CPC 464's again  :D
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: 260Z on 09:19, 27 May 19
@revaldinho (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1776) PM Sent  :)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: TotO on 11:22, 27 May 19
First time I see this topic... And I think about two issues:
1- clean your expansions ports and use short ribbon cables (80%)
2- replace the SGS Z80 with Zilog version Z0840004PSC (20%)

Originally, the CPC 464 was not designed to receive memory expansions (only Floppy drive and AMSDOS ROM)
The DK'Tronics use strong transistors to force the Z80 signals (MREQ and A15 lines) to support RAM and C3 mode.
The X-MEM do not use any transistor and only catch the good timing, when the "CPC" switch is set on "464" to not damage the CPU.

Tests was done on all different kind of 464/664 with all memory mode, demo, games and utilities using C1, C2, C3 and properly work.
Used by hundred 464 owners. Except (pre-ASIC) that have a real incompatibility with "modern" expansions. (may be with DK too?)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 06:45, 28 May 19
@TotO (http://www.cpcwiki.eu/forum/index.php?action=profile;u=290) besides some of the problems I had with the other mem expansions, another major additional point of the thread was / is what @revaldinho (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1776) 's RAM expansion offers. Required if you want to get the cursor for FutureOS on the 464 (no other mem expansion will do, @revaldinho (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1776) 's expansion is the only one AFAIK):
Quote
Like other RAM cards, it provides full DK'Tronics compatibility when used with the CPC464 and
CPC664. This is sufficient to run the vast majority of software requiring additional RAM including
CP/M Plus, demos such as Phortem and Batman Forever and many games.The card also provides a unique 'shadow mode' which enables perfect Amstrad CPC6128 videomode C3 operation on CPC464/664 computers[2]. In shadow mode these older machines can
now run FutureOS and other software relying on this video mode and which previously would run
only on CPC6128s and later machines. Shadow mode can also enable a 464 to run entirely from
the card RAM without using base RAM other than for the video display. This may be useful for
reviving or at least diagnosing CPC464s with faulty internal RAM.
@toto wrote:

Quote
Tests was done on all different kind of 464/664 with all memory mode, demo, games and utilities using C1, C2, C3 and properly work.
Used by hundred 464 owners. Except (pre-ASIC) that have a real incompatibility with "modern" expansions. (may be with DK too?)
See, that is always a bit of a difficult argument I think. There are also hundereds of happy customers (and positive reviews) of certain CPC products on SellMyRetro for the CPC, yet not one of these 100 and more happy users every noticed that - for example - their 2nd disk drive doesn't work at all with that controller, etc. So...

For sure, some of my CPCs also had issues (a dirty expansion port was never one of these, though - bad contact with connector for sure caused problems!). Also, swapping Z80 CPU sometimes helped.

However, most of the mem expansions work 90 % of the time. The remaining 10 % are difficult to diagnose sometimes. @revaldinho (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1776)  put it nicely once, when we had a hard time understanding what was going on with the testing - he said something along the lines l ike "These old computer have so many variables that it is hard to control them all" (don't remember it literally, but it made great sense to me).

Things that work on one machine might fail on another. But in 90 % of the time, it'll work. This thread is / was more about the remaining 10 %  ;)
For sure, the problems that I had in this thread with the expansions were real and not easy to overcome (and some still aren't), so it isn't just a matter of a dirty expansion port or bad cable...

Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: TotO on 13:48, 28 May 19
My two answers are points not discuted since the begin on your topic and the result of 5 years of exchange with X-MEM customers.
Do and understand what you want... When you said to have problems with 4 of your 5 CPC 464, I'm just thinking about that. ;) 

So, if you think that your CPC expansion slot is shiny, may be a good start is to provide your mainboard revisions and CPU model.
By the way, DK'Tronics is a hack as all the RAM expansions for CPC and the only good way to handle RAM is to cut wires and add a PAL.
And the best is to sell them and use CPC 6128 computers for extended systems!  ;D
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 17:06, 28 May 19
Quote from: TotO on 13:48, 28 May 19
My two answers are points not discuted since the begin on your topic and the result of 5 years of exchange with X-MEM customers.
Do and understand what you want... When you said to have problems with 4 of your 5 CPC 464, I'm just thinking about that. ;) 

Well, do and think what you want  - when you say" clean your exapnsion port and check the cable" , I am just thinking about that  -not every 464 user is a morron ;D Maybe it happens when the wind is blowing from the east or the humidity is high?? 
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: GUNHED on 19:03, 28 May 19
Quote from: LambdaMikel on 06:45, 28 May 19
... another major additional point of the thread was / is what @revaldinho (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1776) 's RAM expansion offers. Required if you want to get the cursor for FutureOS on the 464 (no other mem expansion will do, @revaldinho (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1776) 's expansion is the only one AFAIK)...
IMHO that's the major point too!  :) :) :)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: TotO on 19:18, 28 May 19
Quote from: LambdaMikel on 17:06, 28 May 19
when you say" clean your exapnsion port and check the cable" , I am just thinking about that  -not every 464 user is a morron ;D Maybe it happens when the wind is blowing from the east or the humidity is high??
:picard2:
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: GUNHED on 13:06, 29 May 19
Come on guys! Let's work together. Some problems can only be solved with the help of all of us (creators).  :) :) :)


BTW: I totally understand that making hardware is a real hard task. I can't do it. But even doing software makes one freak out once in a while and one can get desperate. We have only very few productive people in the CPC scene. Hope you few can get united.  ;) :)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: revaldinho on 20:21, 29 May 19
I agree with @TotO (http://www.cpcwiki.eu/forum/index.php?action=profile;u=290) that all the '464 memory expansions are a bit of a hack. They all have to back-drive CPU signals which is far from ideal and variations in drive strengths, wiring and contact resistance and local voltages all contribute to not achieving 100% success across all machine revisions and build variations here.

I addressed the back-driving issue when protecting internal memory in two ways in the board design: firstly I ganged up two CPLD pins to drive against the CPU, and secondly I chose to drive RD* low to write protect the internal CPC memory rather than drive MREQ* high, on the basis that it's easier to win a logic level fight against TTL when TTL is trying to pull-up. I've been very up-front in sharing the results of the testing across motherboard types, different CPU types and voltage ranges (see links to the Google Sheet elsewhere in this thread) and overall this strategy seems to have worked well.

At some point though the CPLD also needs to drive an address bit high while the CPU is pulling it low. Again I ganged up two CPLD pins to do this and this seems to be good for DK'tronics mode on all tested machines, but for the unique C3 shadow mode (mainly for FutureOS) @LambdaMikel (http://www.cpcwiki.eu/forum/index.php?action=profile;u=2172)  and I have found that the timing is more susceptible to machine variation. All my own CPC464 motherboards work well in this mode using any CPU type and running the RAM card either off the internal CPC supply, or with an external supply of +4.5V which is all great. However, I have one of LM's Schneider '464s here to debug which will run in C3 shadow mode but needs at least an external supply of at least +5V to be applied. Nothing less will do. I have cleaned up connectors, tried all types of CPUs (Sharp, Mostek, Zilog, ST and even UA880s) and a couple of different CPLDs in the RAM card, but all behave the same on that one particular machine. It's only C3 mode which is affected though - the same machine and card runs fine at lower voltages in DK'tronics mode - and the very same RAM card runs well at lower voltages on my other CPCs.

So, yes I would agree that for RAM expansions the CPC6128 is definitely the better starting point since the flaws of the original '464/'664 implementations are all resolved on the motherboard. In an irrational way though I prefer using my old '464 because that's what I had back in the day. And I prefer the keyboard. And this is retro-computing which defies all laws of logic, though sadly not physics.  :D  My card is still a good option for users who particularly want to use the C3 shadow mode for FutureOS on a CPC464. It appears to be reliable on all machines in DK'tronics mode as far as I can see, and it seems that in the very worst case a good external PSU will resolve issues in the C3 shadow mode with more problematic motherboards. I'm happy to refund anyone who finds otherwise.

I've had a bit of a slow start to CPC projects this year, but I'm still actively supporting all my open source projects and hoping to get a bit more momentum going now (particularly on the Z80Tube card). Any users with issues or feedback positive and negative can PM me or log an issue in the github database. If anyone else is interested in getting hold of one of these '464 cards then I do have a small number available so drop me a PM. I can build more to order but of course there will be a slight delay after the current batch runs out as I'd need to get in more PCBs and components.


Rev.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 21:28, 29 May 19
Quote from: revaldinho on 20:21, 29 May 19If anyone else is interested in getting hold of one of these '464 cards then I do have a small number available so drop me a PM. I can build more to order but of course there will be a slight delay after the current batch runs out as I'd need to get in more PCBs and components.


I could actually use a second one, PM sent  :) 
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 21:29, 29 May 19
Quote from: TotO on 13:48, 28 May 19
So, if you think that your CPC expansion slot is shiny, may be a good start is to provide your mainboard revisions and CPU model.


If you had cared for the content of this thread rather than only stating XMem stats, you would have seen that I have posted all that information, with pictures of the mainboards and CPUs, and test results posted as well... somtimes just stating XMem is great, all 464 users clean your expansion port and ignore the rest of the content in a thread doesn't cut it. Sorry to say.



EDIT - never mind... just forget about it  8) Peace  :)  I admire XMem and I have *3* of it, and I wouldn't wanna live without it - and I mean that. But still, problems should be acknowledged and not swapped under the carpet. (I am NOT saying these are XMem problems... ) All I want is a working mem expansion for the 464, and so far, @revaldinho (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1776) 's comes closest to that.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: XeNoMoRPH on 22:01, 29 May 19
@revaldinho (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1776) , what is Z80Tube card please ?  :o                         
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: revaldinho on 22:39, 29 May 19
Quote from: XeNoMoRPH on 22:01, 29 May 19
@revaldinho (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1776) , what is Z80Tube card please ?  :o


There's another thread for that here: http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/z80tube-running-acorn-co-processors-on-the-amstrad-cpc/ (http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/z80tube-running-acorn-co-processors-on-the-amstrad-cpc/)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: 260Z on 02:46, 31 May 19
Installing FutureOS on the CPC 464 ?


See below  :D
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 07:09, 31 May 19
Your answer disaapeared, but there are a couple of options for ROM for FOS:
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: 260Z on 07:17, 31 May 19
Thanks @LambdaMikel (http://www.cpcwiki.eu/forum/index.php?action=profile;u=2172)

Yea, sorry I thought I had deleted it soon enough  :)
I found a post referencing the installer, and tried it on an emulator.

Great info though, for future 464 users  :D

Cheers,
Rob
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: GUNHED on 19:23, 31 May 19
If you need support for FutureOS just let me know.  :)
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: zhulien on 18:33, 07 July 19
Quote from: LambdaMikel on 06:38, 01 November 18
Gunhead's "Tribute to the sisters" FutureOS Game runs fine on the 464 in C3 mode!
Great game, btw - awesome playability (scrolling!!), music and graphics.  :)

I wished someone created an alternative to chaining all our hardware 'towards' the monitor... the mx4 is great for what it is, but... then when you add a 2nd mx4, it needs to rotate 90 degrees and when you add something to the end of the 2nd one (dd1 for example or a 9th mx4 card), it really is a bit lengthy.  I'd love an 9 slot mx4 board that has 8 of them horizontally behind the cpc and the 9th being the through connector.  That might make the chain of things with memory being most important more reliable.
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: LambdaMikel on 23:04, 07 July 19
I could probably extend the LambdaBoard quite easily to 8 slots... it's just a matter of copy & paste in KiCAD.
You mean that the orientation of the extension cards is parallel to the CPC (like in your picture), or perpendicular?
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: zhulien on 07:03, 08 July 19
Quote from: LambdaMikel on 23:04, 07 July 19
I could probably extend the LambdaBoard quite easily to 8 slots... it's just a matter of copy & paste in KiCAD.
You mean that the orientation of the extension cards is parallel to the CPC (like in your picture), or perpendicular?


if the mx4 board itself was horizontal, then each extension card would be perpendicular to the CPC.  if a 9th slot was still behind it as a through connector, it means less wobble for a dd1 interface at the end of the chain too.  If the Lambdaspeak was within and the M4 Wifi Board, then the cables (not the upright cables) of the Lambdaspeak would stick out back and the M4 SD card would point towards the computer.


Basically:


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[COMPUTER]
Title: Re: Wanted - working Memory Expansion for CPC 464
Post by: xesrjb on 08:31, 05 February 22
Quote from: Duke on 10:27, 07 October 18
Put together a little extended ram tester (for first 512KB only, for now).
It will test regular banking mode, C1 mode and C3 mode.
Will add C2 mode later.

Maybe useful to check various expansions.

Instructions:
RUN"RAM512KB

EDIT: Updated to v1.0.1 - now checks if upper ROM in C3 mode is messing with 0x4000.
EDIT2: Messy source code if anyone is interested -> https://github.com/M4Duke/z80/blob/master/RAM512KB.s (https://github.com/M4Duke/z80/blob/master/RAM512KB.s)


I will try...


xesrjb
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