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CPC Mainboard Versions

Started by nocash, 14:52, 09 April 10

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Terje_Norway

Hi,
Time for the next update on CPC boards. This time I'll go for my GX4000 machines.


GX4000   -   Measures 205 mm x 150 mm (Same size on all three boards)
Serial no. 735-0919698                2700-017P-3   MC0123B [5]  K3      MFR  B
Serial no. 735-0958752                2700-017P-4   MC0123C [6]  K1      MFR  C
Serial no. 735-0959167                2700-017P-4   MC0123C [6]  K2      MFR  C
 
There are several differences between revision B and C 
1.) Have a look just below the SCART connection.
-    R153 is present in Rev B. NOT present in Rev C.
2.) Between Z80A and AY38912/P there are huge differences. 
-    On Rev B You'll find NR2, C2, R1 & R2
-    On Rev C You'll find R135-R142, C2  R1 & R2
3.) Look just below the RGB monitor connection.
-    The following components have both different size, and the location on the board. (Not moved all to long, but different location anyway)
-    D180, C32 & R181
Both point 2.) and 3.) confirms that we are talking about TWO DIFFERENT boards. Not the biggest differences I have to admit, but still different ! ! !


So what "crazy" theory do I have this time  ;)
Well, it is like this.
1.) The board number is MC123 ! !. The number below could mean revision number. In my case Rev B and C
2.) The number below could mean the PCB number. In my case PCB number 5 and 6
     I have also checked ONE 464plus and that number is 7. Perhaps it means number of CPC plus board ? ?
3.) The K numbers. I'd guess it is an indication of production within the different PCB numbers. If You have a look at the top of this posting, You'll find both serial number and K number. The serial numbers confirms my theory ! !
If You have a look at the following PCB, that one is newer than mine (I think). Could we have the serial number for that machine ? ?


http://www.cpcwiki.eu/index.php/File:GX_4000_MC0123C_K4_bilgisayarlarim_736001086319_MA.jpg


What do You think ? ? Is my theory only rubbish, or am I into something.


Yours


Terje Grind
Norway

nocash

#151
> GX4000   -   Measures 205 mm x 150 mm
Many thanks! One more missing detail resolved.

> Have a look just below the SCART connection.
> R153 is present in Rev B. NOT present in Rev C.
But, how having a look at Rev B when there's no photo??? Upload one, please-please!

The details on the differences are cool! Most are sounding just like small re-arrangements, but they are interesting anyways. I wonder what the removed R153 means to the schematic, http://cpcwiki.eu/index.php/File:Edited_GX4000_RGB_Power_Schematic.gif ... does it mean SCART pin 8 is left unconnected in Rev C, or does pin 8 go directly to 10V. Well, might be a silly question, since I could just look on the scans/photos, and eventually see that :-)

> So what "crazy" theory do I have this time  ;)
Oh, no! :-)

I think the FULL board number is "x7nnnnn MCnnnnX", both parts are important. There are some examples where components where added/removed/rearranged and where only the Z7nnnn or only MCnnnn changed.

Only the ending X in MCnnnnX seems to be unimportant (means that only the text layer changed, not the components on the board). On your GX boards the "17P-3" and "17P-4" would indicated changes, and I think the ending X in "123X" seems to be not so important.

And the other numbers [5] K3 and Serial no 735... I am not too sure if one can reconstruct that numbering system (and if doing that would make too much sense). You may need to get hold of thousands of CPCs (and whatever other amstrad hardware like DDI-1 and MP2) to get enough data to see how it was used. EDIT: And probably Amstrad got their own numbering system messed up in some ways, accidently putting wrong serial no's on some computers, then understanding it would be like fighting windmills :-)

The bilgisayarlarim gx4000 pic comes from http://bilgisayarlarim.com/Amstrad/ the picture series do also show the serial no of two gx's and some other amstrad's. Btw. does somebody know who is running that site (couldn't find a contact address on it)? The pics on that page are really nice, showing love in detail.

Terje_Norway

Hi,


First off all. I have tried to take a few pictures of the different GX4000 boards. Unfortunately the quality of my 6-7 years old digital camera, is so bad that the pictures is more or less useless. I'll have a look at it again tomorrow. Previously I have used the scanner on my HP Officejet Pro L7590 printer. The result could be useful.


Now, lets have a look at the 464plus and the 6128plus computers.


6128plus
Serial no. 531-0754346              2700-016P-3    MC0122D [9]  no K     MFR B   (French keyboard)
Serial no. 531-0760453              2700-016P-3    MC0122C [7]  no K     MFR B   (Spanish keyboard)


464plus
Serial no. 531-0782924             2700-016P-3    MC0122B   [6] no K     MFR A   (Spanish keyboard)
Serial no. (only a loose board)   2700-016P-3    MC0122C  [7] no K                  (Bought from the UK)


Let's have a look at my machines.
464plus
The boards looks to be more or less identical, even if the they are 122B [6] and 122C [7]. Anyway, I have found TWO minor differences.
1.) One is concerning IC16.
- On 122C it is 74Ls27N
- On 122B it is PC74HCT02P. There are also two resistors. One between leg 2-8 and between 3-4.
- Further more there are two extra lanes with corresponding holes, neither of theme are used.
2.) Second difference is above the IC15
- On 122B : Diode between R70 and R71
- On 122C : Diode goes between R71 and R72.


See link below
http://www.cpcwiki.eu/imgs/e/e4/Gerald_CPC6128Plus_1990_2700-016P-3_MC0122C.jpg


6128plus
Same problem here. Having a hard time finding differences, but there are a few minor changes.
1.) Difference above IC15
- On 122C : Diode goes between R71 and R72
- On 122D : New layout in this area. D29 and D30 replaces above connection. Also new location on the two black leads. Now both are marked as A and B (Original labeling  :) ) Also more text on the board.


See link below
http://www.cpcwiki.eu/imgs/6/66/CPC464Plus_MC0122D_NightfallCrew.jpg


What can we make up of that ! !


Well to be honest I haven't got a clue. All the boards are 2700-016P-3, which could mean they are the same. The problem is that doesn't make up, since there are several minor changes. Perhaps the magical word is minor. The changes are so small that they are perhaps just adjustments. 
As for the number behind MC0122x, perhaps that could be batch number for the PCBs ? ?


That has to be it for tonight


Yours


Terje Grind
Norway


Devilmarkus

Quote from: nocash on 21:42, 01 May 10
The bilgisayarlarim gx4000 pic comes from http://bilgisayarlarim.com/Amstrad/ the picture series do also show the serial no of two gx's and some other amstrad's. Btw. does somebody know who is running that site (couldn't find a contact address on it)? The pics on that page are really nice, showing love in detail.

This gave me the idea to compare my 3d model to some of their photos:

http://cpc-live.com/CPC464_1.jpg
http://cpc-live.com/CPC464_1.png
http://cpc-live.com/CPC464_2.jpg
http://cpc-live.com/CPC464_2.png
When you put your ear on a hot stove, you can smell how stupid you are ...

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Terje_Norway

Hi,


OK I got a bit bored, so I opened another bunch of CPCs. Now I got 13 machines laying opened  ;D  
This time I have only measures my CPC464 and CPC664 boards.


They are as following :
CPC464             MC0001A       405 mm x 155 mm
CPC464             MC0044D       238 mm x 145 mm
CPC464             MC0099A       237 mm x 108 mm
CPC664             MC0005B       475 mm x 155 mm


Yours


Terje Grind
Norway

nocash

> Unfortunately the quality of my 6-7 years old digital camera, is so bad
Ah, good reason. Then I won't bother you again.
Scan could be great - but, aren't printer/scanner combos paper-feed? Then it could have a hard time when being fed with PCBs :-)

> On 122C it is 74Ls27N
> On 122B it is PC74HCT02P.
Okay, then I was wrong, and the ending letter in MCnnnX is important.
  7427 = triple 3-input NOR
  7402 = quad 2-input NOR
probably both used for same purpose, but the wires on the PCB must have been changed, not just its text layer.

> Now I got 13 machines laying opened  ;D
Aieeeh. I like opening things, too. But usually I have them kept laying around 6 months (or longer) before I get around to reassemble them :-) Hope that won't happen to you, too!

nocash

Added the four new board sizes to http://cpcwiki.eu/index.php/Mainboard_Versions much less unknown ???x??? in red ink now, thanks! Good that checked 464 v1, it seems to be 3mm bigger than 464 v2.

Uhmmmm, now the 464 v3 (medium size) has two possible sizes:
  Markus: 240x150 for MCxxxxx
  Terje: 238x145 for MC0044D
Difference is 2mm width, and 5mm height. What to do now?

Markus, did you measure or calculate it? And Markus+Terje, how far do you trust your own results? :-) Maybe both are correct in case you measured different boards... Markus, do you remember if you used a MC0044D (or other) board?

Devilmarkus

I measured width & height of my board.

If I do remember the boards name?
Look @ the photo I gave you. ;)

My 464 is now assembled well and I don't think to disassemble it again for the next 50 years.
When you put your ear on a hot stove, you can smell how stupid you are ...

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nocash

Ah, okay, that'd be this one http://cpcwiki.eu/index.php/File:CPC464_MC0046A_Markus_top.jpg, the right edge actually looks a bit longer as than in http://cpcwiki.eu/index.php/File:CPC464_Z70375_Tomdalby.jpg, not sure where the difference in height comes from. The distance from screw-holes to board edges looks same, and the holes likely at the same position (assuming that both boards fit in the same case). Anyways, that few millimeters aren't very important.

Devilmarkus

Don't forget: German CPC boards have a shield around.
Maybe that makes the size difference...
When you put your ear on a hot stove, you can smell how stupid you are ...

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Devilmarkus

Maybe funny info:
When I opened the CPC plus today, I noticed that it's AY chip looked a bit smaller than in my old 464!
So I measured it.
35 x 12 mm in CPC plus
37 x 14 mm in old CPC 464!
I only measured the case, not the pins!
When you put your ear on a hot stove, you can smell how stupid you are ...

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nocash

#161
> On 122B it is PC74HCT02P. There are also two resistors.
> One between leg 2-8 and between 3-4.
Terje, they are "pins", not "legs". Well, to be fair, at HOME, I am calling them "legs", too.
And they are numbered anti-clockwise, so upper-right is leg 14 (not 8).

Terje_Norway

Quote from: nocash on 16:00, 05 May 10
> On 122B it is PC74HCT02P. There are also two resistors.
> One between leg 2-8 and between 3-4.
Terje, they are "pins", not "legs". Well, to be fair, at HOME, I am calling them "legs", too.
And they are numbered anti-clockwise, so upper-right is leg 14 (not 8) .


OK, I know it is "pins" and NOT "legs"  ::) , but I think You did understand what I meant, even if wasn't academically correct.


YES, they are numbered anti-clockwise. Like my drawing below :


 1 -   14
 2-   -13
 3-   -12
 4-   -11
 5-   -10
 6-   - 9
 7-   - 8


5 and 10 is marked on the board.


Yours


Terje Grind
Norway

nocash

> I know it is "pins" and NOT "legs"  ::) , but I think
> You did understand what I meant,
Of course I did. Everybody says "legs" and thinks of "legs". But nobody uses it in written language... though I don't know the reason for that. Probably it's a stupid reason :-)

Uploaded Terje's 464+/6128+/GX4000 mainboard scans, and added his description of the differences between the revisions to the mainboard page. And, whew, somebody added the Danish 464 keyboard picture! I thought that one would be hard to get.

Btw. a list of some other "most-wanted" photos is found on the bottom of this page: http://cpcwiki.eu/index.php/File:NoPicture.gif (see the File links section), and a few more on this page: http://cpcwiki.eu/index.php/File:NoPicture.png

Oh, and still missing mainboard sizes:
  6128 version 1 (probably same size as version 2...?)
  6128 version 3 (costdown board)
  Aleste 520 EX (rare cpc clone)

Cu, Martin

arnoldemu

Quote from: nocash on 03:56, 06 May 10
> I know it is "pins" and NOT "legs"  ::) , but I think...
I always say "pins", but "legs" are just as good.

I took some time to photograph some cartridge pcbs, sorry they are not all in focus, my hands are not always steady.

http://www.cpctech.org.uk/100_3234.JPG -pcb "amstro1" has eprom, hardwired links
  http://www.cpctech.org.uk/100_3238.JPG - 2700-023p-1, eprom, not hardwired links
http://www.cpctech.org.uk/100_3239.JPG - pcb underneath for 100_3234.JPG
  http://www.cpctech.org.uk/100_3240.JPG - pcb underneath for 2700..
  http://www.cpctech.org.uk/100_3242.JPG - case (base inside)
  http://www.cpctech.org.uk/100_3243.JPG - case (base outside)
http://www.cpctech.org.uk/100_3244.JPG - case (top outside)
  http://www.cpctech.org.uk/100_3246.JPG - case (top inside, plastic pin broken)
   
Sizes (pcb):
61mm (side) x 52mm (top)
 
box:
68mm (side) x 66mm (top) x 16mm (thick)

 
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My website with coding examples: Unofficial Amstrad WWW Resource

nocash

Amstro1 - neat. And it's LK's are called L's :-) considering that people say that the plus/gx4000 has been a flop, it's amazing how many cartirdge/mainboard revisions were produced.

2700-023p-1 - that's the PCB I got from fano. It's having hardwired (printed/etched) LKs, same as Amstro1. One different thing is that 23p-1 has single-sided soldering points.

arnoldemu

Quote from: nocash on 11:52, 07 May 10
Amstro1 - neat. And it's LK's are called L's :-) considering that people say that the plus/gx4000 has been a flop, it's amazing how many cartirdge/mainboard revisions were produced.

2700-023p-1 - that's the PCB I got from fano. It's having hardwired (printed/etched) LKs, same as Amstro1. One different thing is that 23p-1 has single-sided soldering points.
Maybe Amstrad lost too much money making different pcb revisions  :P

My games. My Games
My website with coding examples: Unofficial Amstrad WWW Resource

robcfg

Hi, folks!


A couple of weeks ago, we discovered a new 6128 motherboard at CPCmaniaco's place, PT NO Z70290, MC0026B, 94V0-ECMM1, Copyright 1985.

I uploaded the picture to the motherboard revisions page.

Terje_Norway

Hi,


I have now remeasured most of my CPC boards, and this time the measurements are 100 % correct.
They are measured with a calibrated DIGITAL CALIPER, so it should be correct  :) .


  464plus &
6128plus                        MC0122C                         282 mm x 140 mm 
CPC664                          MC0005B                         480 mm x 156 mm (New size ! Measured twice)
CPC464                          MC0001A                         405 mm x 155 mm                     

CPC464                          MC0044D                         237 mm x 155 mm (New size! Measured THREE times)
CPC464                          MC0099A                         240 mm x 107 mm 
Schneider CPC6128        MC0025?                         320 mm x 157 mm 
Schneider CPC6128        MC0014?                         320 mm x 157 mm 

Amstrad CPC6128          MC0009B                         320 mm x 157 mm (New size ! Measured twice)
Amstrad CPC6128          MC0020A                         320 mm x 157 mm 
Amstrad CPC6128          MC0020C                         320 mm x 155 mm 

Amstrad CPC6128          MC0020I                          320 mm x 155 mm 


They are measured at their widest point. That does include the EDGE connectors, but not the Centronics connectors as they are soldered to the board.



Yours

Terje Grind

Norway


Gryzor

You must have a looot of time in your hands :D

Thanks for your trouble! But maybe the edge connectors should not be included in the dimensions... For one thing, their size remains constant and therefore the comparison between versions is eschewed. And then, these connectors go out of the normal board limits via the case openings...

Devilmarkus

Last weekend I got an "Amstrad CPC 464" which was sold in Germany.
(Grey keyboard but Amstrad logo)
It has the same mainboard than my other "Schneider" CPC 464.
But 2 things are curious here:
- The LK bridge for "Schneider" was shortened before! Then it was cut to show "Amstrad"...
- The tape connector socket is different (This one here is flattened and doesnt match my other tape drive's connector)

The type-# and PT.NO. are identically to the other photo I uploaded!
When you put your ear on a hot stove, you can smell how stupid you are ...

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Gryzor

Other grey "Amstrads" have shown up before, it was assumed it was a case of stock leftovers or something...

Or, maybe Amstrad broke up with Schneider and so they marketed some qties themselves, using Schneider-designated stock in the process? The re-cut bridge is interesting...

robcfg

Hi folks!


I managed to get my hands on a CPC6128 Z70290, MC0020F board, which we don't have in the wiki list.


It's pretty damaged but will do for the component layout. I'll be uploading a nice picture tonight.

Devilmarkus

For the collectors:
A photo of the German "Amstrad CPC 464" handbook:
When you put your ear on a hot stove, you can smell how stupid you are ...

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Gryzor

Lovely pic! Weird choice of screenshot though, assuming this was late in the machine's life cycle...

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