CPCWiki forum

General Category => Amstrad CPC hardware => Topic started by: Nilquader on 18:06, 26 December 13

Title: 512K RAM Expansion - Schematics?
Post by: Nilquader on 18:06, 26 December 13
I'm trying to build a cheap (and small) 512K RAM expansion for the CPC. Maybe something like this RAM BOX - CPCWiki (http://www.cpcwiki.eu/index.php/RAM_BOX) - Does anybody have the schematics for such a device? I know that there are schematics for the Inicron RAM-BOX available but that one isn't fully compatible.
Title: Re: 512K RAM Expansion - Schematics?
Post by: MacDeath on 19:02, 26 December 13
such card will soon be available... probably for a reasonnable price...


Well you may have to also get a Mother x4 as well...




Cent Pour Cent - CPC News (http://www.centpourcent.net/)




the shop is closed at the moment.
I guess it is a bit of a shame because we can't see the cards in existence...


TotO should let some pages, just disable the "buy" option for the moment.
Title: Re: 512K RAM Expansion - Schematics?
Post by: TotO on 19:17, 26 December 13
No, I can't simply disable the buy option and I can't sell anything before January.
You can see the existing boards from the main page.

Yes, a RAM expansion will be available for an affordable price in some weeks. :)
Title: Re: 512K RAM Expansion - Schematics?
Post by: Nilquader on 19:19, 26 December 13
I wanted to have something very small, so I looked for something like the RAM-BOX (see above). The Motherx4 + RAM-Expansion will be too big to be put into a small case.
Title: Re: 512K RAM Expansion - Schematics?
Post by: TotO on 19:23, 26 December 13
The MX4 expansion boards are 8x5cm formated. (half of a 3" floppy)

Title: Re: 512K RAM Expansion - Schematics?
Post by: MacDeath on 23:43, 26 December 13
Perhaps, you can only plug one card without the Mx4, just need the proper cable I guess?

I was misguided by those 3 thread about the 512K card and failed to see all other cards have their page. ::)
Title: Re: 512K RAM Expansion - Schematics?
Post by: Nilquader on 10:09, 27 December 13
I've been looking for schematics, Not a finished product. Maybe it's possible to put the complete logic into a small CPLD and build an even smaller RAM expansion...
Title: Re: 512K RAM Expansion - Schematics?
Post by: TotO on 20:17, 27 December 13
There is no schematic on Internet actualy.
If you want to build your own expansion using a CPLD, then you got all the technical informations on Internet to start your project from cpcwiki and grimware.

Good luck.
Title: Re: 512K RAM Expansion - Schematics?
Post by: Bryce on 20:46, 27 December 13
As far as I know Yarek released all his schematics (including the RAM expansion you posted) here: CPC4MB RAM upgrade -- 8bit Projects For Everyone (http://8bit.yarek.pl/upgrade/cpc.cpc4mb/index.html)
I've never tried it (you need to create an account and log in), but supposedly everything you need should be there.

Bryce.
Title: Re: 512K RAM Expansion - Schematics?
Post by: TotO on 21:16, 27 December 13
The links are dead as I know.
I have sent a message 1 year ago w/o answer.
Title: Re: 512K RAM Expansion - Schematics?
Post by: Bryce on 22:15, 27 December 13
Oh, I didn't know that. As I said, I've never tried.

Bryce.
Title: Re: 512K RAM Expansion - Schematics?
Post by: TFM on 00:09, 28 December 13
Well, then check out http://www.inicron.de (http://www.inicron.de)


Of course you need Eagle.
Title: Re: 512K RAM Expansion - Schematics?
Post by: Bryce on 00:44, 28 December 13
Quote from: TFM on 00:09, 28 December 13
Well, then check out http://www.inicron.de (http://www.inicron.de)


Of course you need Eagle.

In fact you'll need a commercial version of eagle. You'll also need to hand edit the files to make them Eagle 6.x compatible if you are using a recent version.

Bryce.
Title: Re: 512K RAM Expansion - Schematics?
Post by: TotO on 08:32, 28 December 13
Quote from: Bryce on 22:15, 27 December 13
Oh, I didn't know that. As I said, I've never tried.
Yes, only few links are working on this dead website, and because everybody make links and not backup the content look to be definitively lost, since.
As I know, those expansions only support C0, C4-C7.
Title: Re: 512K RAM Expansion - Schematics?
Post by: beaker on 09:29, 28 December 13
I've got one (Yareks 512k) that Bryce did some work on a year or so back that I want to use with the CPC 464 (hopefully will keep MacDeath happy  ;) ).

If there's anything I can do to help let me know.
Title: Re: 512K RAM Expansion - Schematics?
Post by: TFM on 23:00, 28 December 13
Quote from: TotO on 08:32, 28 December 13
Yes, only few links are working on this dead website, and because everybody make links and not backup the content look to be definitively lost, since.
As I know, those expansions only support C0, C4-C7.


Jareks 4 MB RAM expansion also support C3. I never had a problem with it.
Title: Re: 512K RAM Expansion - Schematics?
Post by: TotO on 23:57, 28 December 13
I answered about the RAM-BOX, for the second part of my post. :)
Title: Re: 512K RAM Expansion - Schematics?
Post by: Nilquader on 01:10, 29 December 13
Well, if you could make some high quality photos so that you can see the traces on the board (at least the ones that are not hidden by chips) and read the chip types, that would help.

Yareks 512k expansion only supports C0, C4-c7? Maybe it's really better to use a CPLD and support everything.
Title: Re: 512K RAM Expansion - Schematics?
Post by: TFM on 04:25, 29 December 13
Some of that should be somewhere in the wiki
Title: Re: 512K RAM Expansion - Schematics?
Post by: beaker on 11:21, 29 December 13
Quote from: Nilquader on 01:10, 29 December 13
Well, if you could make some high quality photos so that you can see the traces on the board (at least the ones that are not hidden by chips) and read the chip types, that would help.

Yareks 512k expansion only supports C0, C4-c7? Maybe it's really better to use a CPLD and support everything.

Are these OK?
Title: Re: 512K RAM Expansion - Schematics?
Post by: Bryce on 12:50, 29 December 13
I just checked back through my mod documents (I document every job with fotos). Here are some hi-res pics I took of Yareks 512K expansion with the connector removed, where more of the connections are visible:

Bryce.


Title: Re: 512K RAM Expansion - Schematics?
Post by: TotO on 14:34, 29 December 13
Difficult to read the IC parts numbers.
I may be wrong, but a fast look on the pictures suggest that this board not support C3 on 464/664.
It's not really a problem, as C3 is used on few 6128 programs only and it may damage the Z80 if handled like the DK'Tronic does.
Title: Re: 512K RAM Expansion - Schematics?
Post by: beaker on 14:50, 29 December 13
You could be right, my CPC464 is in no state to test it at the moment and it does state 6128 on the board.

I guess I'll be buying one of your boards as well when it's ready  :D
Title: Re: 512K RAM Expansion - Schematics?
Post by: TotO on 15:01, 29 December 13
My expansion only support 50% C3 actually. I use a CPLD to fit on a MX4 expansion board, w/o SMD parts.
I have done more tests to fully support C3 on it, for 464/664 users. It's not easy, but gerald look to achieve that.

He explain me how, but I don't get good result actually as I have not his hardware for making tests. :D
It's why I have not released the board for Christmas (6128 only)... I don't what that you need a CPLD update later.
Title: Re: 512K RAM Expansion - Schematics?
Post by: TFM on 05:03, 30 December 13
6128 is the future. 464 and 664 never cared about 6128, so now forget about them. Focus on 6128 and C3 shouldn't be a problem there.  :)  No offense against 464/664 users, but you can't expect everything to be downgraded for you. No offense in general - that's just my opinion and you are entitled to have your own.  :)


EDIT: A quick check to verify &C3 working is to start symbos or FutureOS. In the latter case the mouse arrow leaves traces on screen if &C3 is not properly supported.
Title: Re: 512K RAM Expansion - Schematics?
Post by: beaker on 15:27, 30 December 13
 >:( Offense duly taken, it seems a shame to discount the original 2 iterations of the machine  ;) ;D

Only kidding, if it's too much work to implement then it's probably not worth the hassle, I mean it is more of a hobby these days rather than a viable commercial venture (no one will get rich over it). I've got the 6128 and 6128 plus along with the 464 and 64k RAM so I have my bases covered.

Out of interest, is the RAM in the Symbiface2  fully compatible with the CPC 464?
Title: Re: 512K RAM Expansion - Schematics?
Post by: TotO on 15:53, 30 December 13
Quote from: beaker on 15:27, 30 December 13Out of interest, is the RAM in the Symbiface2  fully compatible with the CPC 464?
Absolutely not. :)
Powered by SMFPacks Menu Editor Mod