Cpc Schematic to Pcb design program

[Joseman]

Hi all

Let's say that *someone* is thinking on doing the job to translate a cpc464 schematic to a PCB design program for, for example, design a small pcb or easily make changes on it or simply make public the job for anyone...

I know that here in the forum there are "cpc-hardware-masters", my questions are:

¿what program is the best for doing such a thing?

¿what will be the best technique to achieve this? ¿use a tester seeking all the tracks and draw line by line all the circuit?

IF the job is 100% correctly, will this program automatically (for example) generate a double sided PCB with the ITX form factor dimensions?

I understand that this new PCB design with all the same ic's and components of the cpc will work 100% EXACTLY than a real cpc, or the diferent position of the components on the board and tracks longer or shorter than originally will affect in any form timings or erratic behaviors?

Thanks
Joseman

[Bryce]

Hi Joseman,
          first of all, the sensible way of doing something like this, would be to take the schematics, which can be found in the Service Manuals or as seperate graphic files on the wiki, and create an electronic schematic. To do this you could use Eagle, but the freeware version of this is limited too much to create a PCB of this size or complexity, so you would need to buy the full version. There are other software solutions such as OrCAD or Protel, but they cost big money. Do you have any layout software already? Or experience using them? Otherwise it's going to be an uphill battle. But once the schematic has been completed, you can choose the size and shape of the PCB yourself and automatically create layouts. You'll also have the problem, that many parts won't be included in the standard libraries, so you might have to create many parts from scratch. It's a big project.
As far as the component position is concerned, there are one or two things you would have to observe, such as the position of the crystal relative to its inverter/capacitors and the CPU and also the stabilising capacitors for each IC should be as close as possible, but other than that, the parts can be pretty much anywhere you want, at 4Mhz the component positions aren't that critical for timing, although you should avoid really long tracks between parts, so that the PCB isn't too sensitive to external interference, every track is a potential antenna.

Bryce.

[robcfg]

MAybe PCB Artist could be of help.

[Bryce]

PCB Artist is one of those packages that doesn't create the output locally, ie: you can't make your own boards, you can only send them to Advanced Circuits for production. If you intend etching your own boards at home, or even want to be able to choose the PCB manufacturer yourself, then I wouldn't recommend this type of package.

Bryce.

[Octoate]

I normally use Eagle, but, as Bryce already wrote, it is not suitable for this job in the freeware edition. There are two open source alternatives for electronic designs, which I have never tested, but should do the work:

- KiCad: http://www.lis.inpg.fr/realise_au_lis/kicad/
- gEDA: http://www.gpleda.org/

If you want to work under Windows, you can only use KiCad, because AFAIK Windows support is very limited for the gEDA tools.

[fano]

Speaking about CPC hardware , which parts (except Gate Array and ROMs) are difficult to get or to replace with an equivalent one ?

[Joseman]

Thanks for the tips

say that i'm not familiarized yet with any electronic program, well, even i'm starting to learn some digital electronic :S

Is more a thought than a possible real thing, but oh well, dream is free

I have the schematics of the cpc (by the way, any high quality scan out there?)

Even I have a cpc 464 revision 1 (pcb larger and tracks well defined and easy to analyze), I read on grimware about the cpc 464 revision 0 (the original beast), I don't know if the revision 0 (1983) is easy to get one, ¿any information of how units where sold of this revision?, seems to me that perhaps was the first stock bach of cpc's...

About the programs that you're recommending: Orcad, Protel or Eagle, focused on the cpc, what of the 3 will do the best job, what of the 3 has the best component libraries for the cpc?

Bryce comments "that many parts won't be included in the standard libraries, so you might have to create many parts from scratch", what of the 3 programs will have more cpc-parts? I understand that some parts like the gate array has to be defined for the programs, telling them his pinout or someting like this? Perhaps someone have already made this?

fano: "Speaking about CPC hardware , which parts (except Gate Array and ROMs) are difficult to get or to replace with an equivalent one ? "

Well allways we could use the parts of a real cpc ?

Regars Joseman

[fano]

Well allways we could use the parts of a real cpc ?

I am exactly in the same situation, programming is my first hobby but there is long time (20 years!) i'd like to do something for CPC electronics so i am trying to learn and to understand.Some parts are discontinued or specific like GA and our CPCs are not eternal (one of mine is out of order , two seems weak (maybe capacitors there))

[steve]

I have the schematics of the cpc (by the way, any high quality scan out there?)

Well allways we could use the parts of a real cpc ?

Regars Joseman

You could use some parts from a "donor" CPC (Especially the case and keyboard), or you could try to copy the KC compact which was a clone that used TTL instead of the ULA.

Or, there are many videos on youtube about a CPC that has been built using an FPGA:


http://www.youtube.com/watch?v=jIVzQPjCVCE#

The guy is french and I cannot read french, but there may be a website somewhere with details about how it was done.

Sorry, the link worked in preview, but becomes invalid when posted.

[redbox]

You could use some parts from a "donor" CPC

I like this idea, but regarding the Chips etc.


It would be nice to have a say, mini-ITX sized motherboard and then get the Chips (Z80, CRTC etc etc) out of a donor CPC and solder them on (or even better put them into sockets).


Could be a cool way of re-using and kind of preserving original hardware.

[Gryzor]

I'm not sure what you did with the YT link. You just need to paste the URL in your text, nothing else...

[steve]

Yes, that's what I did and it worked when I previewed it but when I posted, the link was reported as "invalid".