If there are any Replica-1 Plus or L-Star Plus users who use the expansion port on these devices to control external devices (LED's, switches, relays, etc.) using either BASIC peeks and pokes or assembly, I would like to get some ideas from you on how to do this.
we have already texted each other via PM but for everyone's convenience I would like to respond to you here as well.
You are already aware of the first one, but maybe others are not. ;-)
Among other things it contains a 65C22, all unused I/O lines have been routed to a pair of header connectors so they can be used at will.
All the details about the VIA lines and addressing are in the manual.
This project is totally open-source (CC BY 4.0), it is based on to a 65C22 plus a microcontroller and provides plenty of I/O lines, both analog and digital, plus if needed 1-Wire and I2C.
Provided ASM and BASIC routines allow you to interact both with the microcontroller and directly with VIA.
You can really do anything with this board, but since you're using the Replica-1+ it will be necessary to remap the board address to not generate collisions (also routines must be updated accordingly).
At the bottom of the page you will also find instructions for a less complex but equally interesting I/O board.
I hope that I have been helpful!
PS L-STAR: never heard about it, too bad it seems to be discontinued but I'll definitely have a look on it!
Thanks for your info as always, Claudio. I think it would be fun to build a simple IO board, so your sharing of that is very appreciated. I have built a few IO boards for the Z80 RC2014, which I control with the Monitor or BASIC on that system. Doing the same for a R1+ would be very satisfying.
Thank you, Alex!
BTW just for fun here's a small video I made a few years ago about the predecessor of the IO-RTC... veeeery basic, yet functional!
I took this miniature railway to a NERD show in 2019, it ran for two days in a row and it was a great success!