Author Topic: X-MEM, a new memory expansion for all CPC.  (Read 111301 times)

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Offline TotO

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #125 on: 15:20, 10 June 14 »
La X-MEM est fournis avec des outils pour faciliter l'installation et la gestion des ROMs.
Oui, des programmes comme Discology sont capable de tirer pleinement parti de la carte sans changer quoi que se soit, car elle est conforme aux spécifications d'Amstrad et 100% compatible avec les extensions DK'Tronics.

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Offline TotO

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #126 on: 15:29, 10 June 14 »
Some X-MEM NEWS:


First, thank you for all your pre-orders and not for wasting my week-ends!  ;D

I know that many peoples are waiting their board, but understand that took me more times than expected if you pre-order X-MEM with MiniBooster and MotherX4 too. :)
So, please be patient because I do the best for making them available as soon as possible.

Actually, I have build FOUR batch and shipped them!
Speaking quantities, it's around 40 X-MEM on the way or already arrived[nb]In Brazil, arrived=lost in time[/nb].

I have TWO more batch to build now and the 7th is near to be closed!
Than mean, around 70 CPC will run in the next months with 512K ROM and 512K RAM!!!

It's amazing, because that means a new users base should run tools and games using this extra power is definitively viable.
30 years after the CPC was born, we should considerate to be enough to start a new life. :)

Have fun with your CPCs my friends,

  TotO.
« Last Edit: 16:30, 10 June 14 by TotO »
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Offline pelrun

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #127 on: 15:50, 10 June 14 »
Yaaaaaaaaaaaaaaay! *flails around like Kermit*

Offline PhilZeVibe

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #128 on: 17:40, 10 June 14 »
I'm curious about the 512KB ROM limit that has been chosen for the X-MEM.
As you know, the Amstrad CPC can handle 4MB ROM, and the Amstrad Plus can handle 2MB ROM.

So, is it because it would have been much more costly to use 2MB (or 4MB) ROM expansion for the X-MEM?
Or is it because "512KB ROM should be enough for anyone" ©Bill Gates?  :)
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Online Bryce

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #129 on: 18:06, 10 June 14 »
I'm curious about the 512KB ROM limit that has been chosen for the X-MEM.
As you know, the Amstrad CPC can handle 4MB ROM, and the Amstrad Plus can handle 2MB ROM.

So, is it because it would have been much more costly to use 2MB (or 4MB) ROM expansion for the X-MEM?
Or is it because "512KB ROM should be enough for anyone" ©Bill Gates?  :)

It think it has more to do with the fact that offering hardware with 4MB of ROM is kind of pointless. As the MegaFlash and other devices have shown, due to each 16K ROM requiring a little bit of the base 64K RAM, even 512K of ROM can't practically be used without encountering problems on the CPC. You can have 32 ROMs installed, but most of them won't run because too much RAM has been used up. 4MB of ROM is the theoretical limit for addressing ROMs, but the method that the CPC uses to keep track of their presence means that the practical limit is considerably lower.

Bryce.

Bryce.

Offline TotO

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #130 on: 18:22, 10 June 14 »

If you considerate that is a limit... :D


Then X-MEM was first designed to be a RAM expansion.
After putting the logic inside a CPLD, I got free space on the PCB design, so 3 choices was offered to me:
- leave the free space and put a nerd logo
- put 2x 512K RAM IC
- put 1x 512K RAM / 1x512 ROM (and use my work on the CTC-AY to handle booting mode)


I have took a look about the 2MB ROM IC, but it look that they are 40pins and not 32pins, so they can't physically fit on the board. Last but not least, they are only 64K page programmable. That is not possible on CPC.
Finally, I will have missed free I/O pin to handle the extra address lines... So, no regret.


But, you have to know that the X-MEM decode the A8 address and all the ROM bit.
Than mean that it's possible to :
- Put a second board (Y-MEM) to extend the RAM and the ROM to 1MB/1MB. (tested with success)
- Use the board jumper for disabling the ROM part and use a biggest ROM board instead. (Z-MEM?)


All will be possible next, depending what peoples will do fist with the X-MEM.
(remember than since 30 years, only few programs use 256K RAM and 64K ROM...)


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Offline Prodatron

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #131 on: 19:01, 10 June 14 »
Than mean, around 70 CPC will run in the next months with 512K ROM and 512K RAM!!!

It's amazing, because that means a new users base should run tools and games using this extra power is definitively viable.
30 years after the CPC was born, we should considerate to be enough to start a new life. :)
That's great indeed!  :)
And I am looking forward to Y-MEM! :P


GRAPHICAL Z80 MULTITASKING OPERATING SYSTEM

Offline SyX

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #132 on: 19:02, 10 June 14 »
In Brazil, arrived=lost in time
Yes, the package remains in Curitiba, the brazillian equivalent to the Bermude Triangle for postal service  :'(

Offline Gryzor

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #133 on: 20:19, 10 June 14 »
I'm curious about the 512KB ROM limit that has been chosen for the X-MEM.
As you know, the Amstrad CPC can handle 4MB ROM, and the Amstrad Plus can handle 2MB ROM.


TFM? Is that you? Damn, the forum database must be broken.

Offline PhilZeVibe

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #134 on: 20:57, 10 June 14 »
Hehe! :)
If you replace the word "ROM" with "RAM" in my message, that would be true. ;)

But I'm only talking about Amstrad friendly standard limitations here.
2MB ROM on Plus and 4MB ROM on CPCs are what Amstrad's hardware designers allowed as addressable ROM space.

But, on the other hand, the standard RAM mechanism tailored by Amstrad gives space for only 512KB(+64KB)!
So what TFM preach is to use non standard RAM extensions that goes beyond that limitation.

And that's bad I think, because RAM devices that goes beyond 512KB are frankly alien to the Amstrad CPC/Plus DNA.

So really, the point I'm making here is far different than the usual TFM rant  ;)
« Last Edit: 21:19, 10 June 14 by phi2x »
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Offline gerald

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #135 on: 21:42, 10 June 14 »
What would be the use case of 2MB of ROM ?
  - Games ? 2MB will never be enough, and you are either limited to 8/16/32 initialised ROM with standard FW. Using all 25x slots would require some king of added filesystem.
  - Application ? Not sure there are enough available to fill the 2MB, and we are still limited by FW.
  - OS ? are we talking CPC or another Z80 based computer ? No offence to FutureOs or SymbOS, but their ecosystem is really limited, and most user stick to good old games !

Mass storage (CF/SD) would be better. But for it to be usefull, we need a properly AMSDOS integrated standard filesystem like FAT32, with helpers for allowing all the CPC game/app/(demo?) to run from it with little patching as possible.




Offline MacDeath

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #136 on: 22:21, 10 June 14 »
compare this to some sort of HDD... massive storage or easily available content.

I mean, when you had 20mb on an HDD with your PC1640, the PC1640 wouldn't try to read all it every cycles...


Offline PhilZeVibe

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #137 on: 22:26, 10 June 14 »
What would be the use case of 2MB of ROM ?
At least there is someone (Yarek) that felt this was important enough to actually make real hardware to use all the 4MB ROM address space:
http://cpcwiki.eu/index.php/CPC.Flash

Then, whether or not it's a pointless exercise I honestly can't tell. But some people use their CPC way more than I am.
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Offline beaker

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #138 on: 23:06, 10 June 14 »
Yes, important enough to make a 4MB module but if it was anything like my 512k module he forgot to coat the PCB after apparently so my traces corroded  >:(

Offline joska

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #139 on: 00:32, 11 June 14 »
Great stuff :) I have flash-chips in a drawer, they were intended for a home-brewed Megaflash but this looks a lot easier so I just ordered a X-MEM.

Offline TCMSLP

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #140 on: 15:55, 11 June 14 »

I don't quite understand the use of ROM here.  Does this mean we can upload our own ROMS (for example PARADOS) from the CPC?

I have a standard 464 with Piotr's DDI-1 clone on order.  I'm thinking the DDI-1, X4 and X-Mem would be an ideal combination;  assuming I can solve the lack of passthrough on both the X4 and DDI-1.





Offline CraigsBar

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #141 on: 16:31, 11 June 14 »
I don't quite understand the use of ROM here.  Does this mean we can upload our own ROMS (for example PARADOS) from the CPC?

I have a standard 464 with Piotr's DDI-1 clone on order.  I'm thinking the DDI-1, X4 and X-Mem would be an ideal combination;  assuming I can solve the lack of passthrough on both the X4 and DDI-1.

For Parados in ddi-1 you just need to swap the eprom as amsdos is socketed in the ddi-1 interface. If you want a Parados eprom I can post you one as I have a spare.

The x4 has a pass through I believe, you just need an edge connector cable for it, and that is the tricky bit.

Craig

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Offline TotO

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #142 on: 18:36, 11 June 14 »
Piotr said that he should provide a 50-pin version instead of an edge version.
That will allow to:
- plug an Edge ribbon cable to the CPC
- plug a Centronics ribbon cable to the CPC/PLUS
- plug a pin-to-pin ribbon cable to the MotherX4 pass-through connector

So yes, 464+DDI-1+X-MEM = good combo.
About Parados, as I know Piotr put a switch into his DDI to chose between both.  :-\
(else, it work fine on ROM 6 too)
« Last Edit: 19:47, 11 June 14 by TotO »
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Offline TFM

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #143 on: 19:08, 11 June 14 »

TFM? Is that you? Damn, the forum database must be broken.

No, no, a well done tape deck and 64 KB of ROM is fully enought. Also we should be only able to access one 16 KB part of the 64 KB ROM at a time. Anything else is overkill.  ;)
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Offline TFM

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #144 on: 19:11, 11 June 14 »
But, on the other hand, the standard RAM mechanism tailored by Amstrad gives space for only 512KB(+64KB)!
So what TFM preach is to use non standard RAM extensions that goes beyond that limitation.
And that's bad I think, because RAM devices that goes beyond 512KB are frankly alien to the Amstrad CPC/Plus DNA.
So really, the point I'm making here is far different than the usual TFM rant  ;)

That´s right, I broke down non-existing barriers in my mind  ;) ;) ;)
TFM of FutureSoft
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Offline TotO

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #145 on: 19:16, 11 June 14 »
The X-MEM allow to access the 512K RAM as well as the 6128's 64K RAM.
640K aught to be enough for everyones?  :-\
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Offline TCMSLP

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #146 on: 00:23, 12 June 14 »

CraigsBar:  I figured Parados was an additional ROM;  I didn't realise it was a replacement ROM for AMSDOS.  If you do have a spare, that would be very kind of you.

TotO: Oops - in hindsight perhaps I should have ordered the 50 pin DDI-1.  Although, at the time I hadn't started lusting after the X4 and X-Mem.

My current intention is to use the DDI-1 (+ 3.5" floppy) and 'cpmtools' under Linux to exchange data to/from CPC & PC.   I've also ordered the Gotek floppy emulator although after reading cpcwiki there seems to be multiple approaches (custom firmware vs conversion of disk images to a raw gotek-friendly format).   It seems either solution (gotek or floppy) would benefit greatly from PARADOS.

Offline CraigsBar

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #147 on: 00:34, 12 June 14 »
CraigsBar:  I figured Parados was an additional ROM;  I didn't realise it was a replacement ROM for AMSDOS.  If you do have a spare, that would be very kind of you.


Yes, ParaDOS is awesome and a total replacement for AmsDOS with added goodies of just about every format known to the CPC world and a really handy tool for file copy and formatting etc..


Well worth it. Let me know your postal address in a Private Message and I'll pop it in the post.


Regards


Craig

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Offline dcdrac

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #148 on: 00:48, 12 June 14 »
Xmem will work best with parados? which would be good as I have it on cartridge

Offline OCT

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Re: X-MEM, a new memory expansion for all CPC.
« Reply #149 on: 02:53, 12 June 14 »
new memory expansion for ALL CPC
[...]
The main advantage is to allow to customize the boot by replacing the Lower/Upper ROM 0 for a full softwares compatibility.

Exemple:
- 464 with switch to BASIC 1.1 and FW3.0
- 6128 with switch to BASIC 1.0 and FW 1.0
- 6128 with switch to BASIC 1.1 and FW3.x

The RAM part is compatible with Amstrad / DK'Tronics / Dobbertin expansions.
The main advantage is to allow to handle all the PAL modes (RMR) over the 512K of memory (C0-FF).

The memory should be used as a RAM Drive C and can be shared with CP/M. (here boot from FW3.13 and CP/M ROM)
[...]
The X-MEM push all CPC to the same level of compatibility.
Since some people have ordered this for a Plus, do I correctly understand X-MEM works on both the CPC6128 and the CPC6128plus?
While it overrides the regular ROM 0 (on the internal PCB or Plus cartridge), can it do the same for ROM 7 on either machine (e.g. to replace AMSDOS by ParaDOS if need be) ?
I recall from MegaFlash Progress that ROMDIS 7 wasn't considered possible on (at least some of) the "classic" CPCs (any replacement DOS without hardware mod had to use a lower and potentially incompatible ROM number),
but feasible on the Plus (with the replacement such as ParaDOS still appearing at number 7 when in X-MEM?).
« Last Edit: 03:21, 12 June 14 by OCT »