Here’s a picture of the progress so far. It now also includes a RTC (Real Time Clock) module. What you might also notice is the flat cable I attached between the serial card and the serial to USB connector. That connector, as you can see in previous posts, was attached directly to the serial print and the USB cable on top of that. This was kind of a wobbly situation that generated transmission errors. By using the flat cable, the converter module and the USB cable can lay flat on the table, not putting undue strain on the connections.
The latest board is an IDE module to be able to connect a floppy or hard disk drive. My brother sent me a 3,5 inch floppy drive, and an acquintance is sending me a flat cable I can use to connect it. So that will be the next addition.