Making expansions

[Fran123]

Hi

Dou you know a web page or book that explains the expansion ports signals? 

I would like to create several IO devices and memory (ram and rom) expansions.

I know there are options to buy them but I like electronic and I want to understand the communication process betwen the z80 and the external device.

Thank you very much and happy New year

[Brocky]

Hi

Dou you know a web page or book that explains the expansion ports signals?

I would like to create several IO devices and memory (ram and rom) expansions.

I know there are options to buy them but I like electronic and I want to understand the communication process betwen the z80 and the external device.

Thank you very much and happy New year

you mean this? 
https://www.cpcwiki.eu/index.php/Connector:Expansion_port

[Bryce]

Hi

Dou you know a web page or book that explains the expansion ports signals?

I would like to create several IO devices and memory (ram and rom) expansions.

I know there are options to buy them but I like electronic and I want to understand the communication process betwen the z80 and the external device.

Thank you very much and happy New year

Basically the port provides the full data and address bus (both unbuffered), the clock, sound and some control signals (both outwards and inwards). Depending on what you intend building, the most important thing to understand is how the Amstrad assigned certain functions to particular addresses. Your device will need to (at least partially) decode the address bus to enable the chips on your expansion and/or set the correct inhibit signals on the expansion port to take control. This is a good place to start: https://www.cpcwiki.eu/index.php/I/O_Port_Summary 

Bryce.

[eto]

You can also have a look at some books that describe hardware expansions. The site acpc.me has a large collection of books in many languages. 

E.g. "Understanding and Expanding the AMSTRAD" has a whole chapter about expansions. Something like that could also help understanding how to build your expansions. 

[SerErris]

Unfortunately in German, but the best book about it is this:
https://k1.spdns.de/Vintage/Schneider%20CPC/Das%20Scheider%20CPC%20Systembuch.pdf

[McArti0]

the communication process betwen the z80 ...

https://www.zilog.com/docs/z80/um0080.pdf

Figure 7 page 11 (25 pdf)