I am an engineer and I have worked in electronic hardware development since 1994. Before that, I have written professional software since 1980. First for Commodore computers, later for MS DOS.
My first own computer was a Commodore VIC-20 and  in 1983, I have bought my first C64.  
After watching some repair videos of old retro-computers on YT (mainly Jan Beta), I have tried to switch on my good old C64  in 2018 - after being powered off for about 28 years. I could not believe my eyes, it worked and I was probably as fascinated as I was, when switching it on for the first time. Soon,  the C64 setup became kind of a fix installation in my lab.   
My interest in the Commodore retro-computers is, besides collecting and repairing them, to develop some new hardware gadgets for them. Those projects are strictly non-profit, open hardware and are/will be  published in my 
  github repositories
   for everybody to build. A complete Overview of all my github projects can be found here: 
https://github.com/svenpetersen1965/Project-overview
My goal is to provide some well tested, documented and easy to build projects. I try to document and test them well, before I publish them.    
My mostly Commodore related Thingiverse designs are here:   https://www.thingiverse.com/svenpetersen1965/designs
   
You can meet me on Twitter and follow my projects while they happen: 
  @svenpetersen191
   
I am also active in the FB group 
  "Commodore New Tech"
   and others. 
Besides colaborating with other websites, that proviode resources on Commodore computers, like 
  zimmers.net
   and 
retro-commodore.eu, I upload, what I can find and what is still missed to archive.org.