This is a beginning of a much larger project. For now, I will just concentrate on making a serial connexion to Cambridge Z88 computer. If you are impatient, just scroll to the end of the article.
I must confess here that I have a certain corner of my heart reserved for portable computers with Z80 processor. It is the thought of the glimpse of the dream about digital nomad the authors of these machines had. Of course, the computers that survived that long do not support modern technologies, but let us not rush…
These are the specifications for both the Z88 serial cable (from the Z88 User Manual) and for the different serial connectors I found at home.
At the end, I found the best specification in the Z88 wiki. I chose a RS232 extension cable, which has male connector on one end and the female one on another. The wires inside the connectors (and cable) are color-coded, so it was easy to find the wires belonging to the pins I needed. I resoldered the wires at the female connector.
Afterwards, I enclosed the connectors again and connected Z88 with my little laptop through a USB-to-serial adapter. Then I created a 9600 baud connection in my terminal program. This program is rather rudimentary (for example, it has no local echo), but it was sufficient for this simple task. And then I tested the connexion. You can watch the results in this video.