Amstrad CPC 6128 (US version) and Zaxon's 4MB expansion card

[HigashiJun]

When time allows, I'll have to check the interface carefully...

Also waiting for my other US CPC 6128 to arrive, so I can see if there's a problem with my actual machine.

[HigashiJun]

Finally received my second CPC 6128 (US version) today.

I tried to connect the 4MB card and I have the same issue...

So, either the card is defective or US version CPCs are not compatible for an unknown reason (though it is unlikely the CPC is the culprit).

I will have to check the card itself when time permits.

Cheers.

[GUNHED]

Good luck!

[Bryce]

Finally received my second CPC 6128 (US version) today.

I tried to connect the 4MB card and I have the same issue...

So, either the card is defective or US version CPCs are not compatible for an unknown reason (though it is unlikely the CPC is the culprit).

I will have to check the card itself when time permits.

Cheers.

There is absolutely NO chance that the US CPC is not compatible.

Bryce.

[GUNHED]

Why not? Early version CPC6128 had a different interrupt behaviour, this was the problem for a commercial game back the day, which worked on one computer, but not on the other. Depending on the way the card works it would be worth to check with different (non-US) CPCs.

[Bryce]

Why not? Early version CPC6128 had a different interrupt behaviour, this was the problem for a commercial game back the day, which worked on one computer, but not on the other. Depending on the way the card works it would be worth to check with different (non-US) CPCs.

Show me the difference, either in a schematic or in the firmware.

Bryce.

[dragon]

Show me the difference, either in a schematic or in the firmware.

Bryce.

There are expansions out there that not work well  with a sgs cpu...


Others that can't replace rom 7 in many 6128 cpcs.


So we can't asume out of the box that the u.s cpcs can have or not a incompatibility.


The reality for now was these mainboard revisions  aren't mounted in normal cpcs.


The best he should do was check de expansion in a normal 6128.

[Bryce]

There are expansions out there that not work well  with a sgs cpu.

Ok, but that's not a US difference, it's a CPU difference. An EU CPC would have the same issue with that CPU.

Others that can't replace rom 7 in many 6128 cpcs.

According to the schematic, no non plus 6128 should be able to swap ROM 7. It's glitch that it happens to work with certain CPC's.

So we can't asume out of the box that the u.s cpcs can have or not a incompatibility.

We can't assume that ANY CPC neither US nor EU might have an issue with certain hardware.

The best he should do was check de expansion in a normal 6128.

Define "normal"? Even within the EU there are many variations.

Bryce.

[gerald]

The reality for now was these mainboard revisions  aren't mounted in normal cpcs.

Which board revision is mounted in these gringo CPC ?

[dragon]

Are two September models and Novembers models.


Septemper mount Board: PT NO Z70270, MC0016A /17A/18A

The picture of the cpc wiki was taken from my solavox.

November mount another later board.

[dragon]

Define "normal"? Even within the EU there are many variations.

Bryce.

A cpc with a board don't designed to pass fcc standard.


"According to the schematic, no non plus 6128 should be able to swap ROM 7. It's glitch that it happens to work with certain CPC's."

If remember o.k there is a signal not connected in the pcbs except in the cost down model.

[Bryce]

A cpc with a board don't designed to pass fcc standard.


"According to the schematic, no non plus 6128 should be able to swap ROM 7. It's glitch that it happens to work with certain CPC's."

If remember o.k there is a signal not connected in the pcbs except in the cost down model.

FCC is an EMC certification, it doesn't change the function of the device.
I am not aware of this signal. Can you show me it in a schematic?

Bryce.

[dragon]

FCC is an EMC certification, it doesn't change the function of the device.
I am not aware of this signal. Can you show me it in a schematic?

Bryce.

http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/disabling-rom-7/

"[size=78%]As I mentioned before, on a standard 6128, ROM 7 isn't connected to the /ROMDIS signal, so connecting the LowerROM Board will just disable ROM 0." [/size]

[Bryce]

Yes, that's the difference between a classic CPC and a PLUS CPC. Not a difference between Classic versions.

Bryce.

[dragon]

Yes, that's the difference between a classic CPC and a PLUS CPC. Not a difference between Classic versions.

Bryce.
[/quote
I understand you in these thread that the v1 6128 don't have to romdis enabled. I was thinking in terms of v1 pcb v2 pcb as described in the wiki.

[GUNHED]

If remember o.k there is a signal not connected in the pcbs except in the cost down model.

Or most of the CPC6128 with centronics ports. Actually I have quite some CPC6128 which properly can replace ROM 7 through a external ROM box. I have only one CPC6128 which can't do it.

Dobbertin was producing 224 KB ROM expansion cards in the 80ies / 90ies for the CPC, they were able to replace ROM 7 on CPCs which could do it.

But back to topic, I don't think that in this case the ROM 7 is a problem. A double occupied ROM 7 would only crash the system if both ROM 7's contain different content.

The other thing is interrupt timing which I pointed out before. And don't ask me for schematics, it's what happened back the day. However, it's probably unlikely to be able to get two of the very early CPCs.

[dragon]

Interesting I  don't know in my solavox support Rom 7 swap.

[GUNHED]

Interesting I  don't know in my solavox support Rom 7 swap.

You can use any (Flash)ROM board which supports ROM 7. If it works it works. If the CPC does a crash, then ROM 7 can't be replaced. Good luck!!!

[VintageAdvantage]

 Did Zaxon ever reply to the questions?  Did you ever reach out to him?

[HigashiJun]

Did Zaxon ever reply to the questions?  Did you ever reach out to him?

I tried to contact Zaxon once on SellMyRetro and I never had a reply.

As I am not the kind of guy chasing up somebody just to get a answer, I will surely not try again.

[VintageAdvantage]

I tried to contact Zaxon once on SellMyRetro and I never had a reply.

As I am not the kind of guy chasing up somebody just to get a answer, I will surely not try again.

Wow, you are too nice... if I paid money for something that doesn't work, and the guy doesn't respond and is not trying to help me, after I made sure that it's not my hardware, I am sending the shit back... and leave negative feedback, depending on how difficult the return was. No wonder he is treating the CPC community like this if nobody is exercising their rights and leaves proper feedback...
And it also doesn't seem to be fair to the CPC community / board here that we should be spending time diagnosing and trying to fix up his "engineering miracles". So I hope you AT LEAST left negative feedback on SellMyRetro for letting him treat you that way! Other buyers need to be warned and protected (if not from the product, then from the "customer service").

[HigashiJun]

Wow, you are too nice... if I paid money for something that doesn't work, and the guy doesn't respond and is not trying to help me, after I made sure that it's not my hardware, I am sending the shit back... and leave negative feedback, depending on how difficult the return was. No wonder he is treating the CPC community like this if nobody is exercising their rights and leaves proper feedback...
And it also doesn't seem to be fair to the CPC community / board here that we should be spending time diagnosing and trying to fix up his "engineering miracles". So I hope you AT LEAST left negative feedback on SellMyRetro for letting him treat you that way! Other buyers need to be warned and protected (if not from the product, then from the "customer service").

Yes, I know... I always try to be positive and I do not want to leave negative feedback, even on Ebay, unless a guy is really proven to be dishonest...

[Bryce]

No wonder he is treating the CPC community like this if nobody is exercising their rights and leaves proper feedback...
And it also doesn't seem to be fair to the CPC community / board here that we should be spending time diagnosing and trying to fix up his "engineering miracles". So I hope you AT LEAST left negative feedback on SellMyRetro for letting him treat you that way! Other buyers need to be warned and protected (if not from the product, then from the "customer service").

I don't think a seller treats their customers bad because nobody complains. He treats them bad because that's the type of person he is. I bought 1 product from him a long time ago, got no answers to multiple email questions and gave up. I mentioned it here and warned people to avoid this seller for several reasons, but people still buy his gear and still get crap support.


Bryce.

[leZone]

Hello !
I want to add "my" informations about the "USA" CPC 6128.

As far as i know :
Produced September 1985 : Amstrad text on screen ; MC0016A (higher serial found 8409) ; yellow A
Produced October 1985 : Solavox text on screen ; MC0026B ?? (higher serial found 1261) : yellow M
Produced November 1985 : Solavox text on screen ; MC0026B (higher serial found 3628) ; yellow O

All have the famous Indescomp Chicago sticker on back, and the so strange "Color" instead of "Colour" text on the top case
I never saw the "spanish" stickers on keyboard except here on this topic. Perhaps it was just an option let to the final user add it, like we can found those kind of stickers for "Schneider" models.

About the monitor.:
I finally got an "USA" monitor ! (in France)
It's a GT65, with 120V 60Hz PSU + modification inside wich looks official (after market ?) to adapt it in 220/240V 50Hz
As you can see, the serial number sticker have the same design than the computer. I think it means the serials was shared between hardware, then, there is probably less september 85 computers than expected because some number was used for monitors.

I'm interested about all informations, and if a CTM-644-2 "USA" exists or not ?
Does these computers travel overseas or not ? It seems they was never be sold in the USA, but be sold in europe instead.

[GUNHED]

Ah wonderful. It has the great Centronics ports like in Germany too. Way better than these dodgy edge connectors.    My US CTM644 had a 2nd small PCB for Power adjustment too.