I already asked him but didn't get a reply so I deduced he wasn't interested.
Here is a copy of the reply I made last night to your second email:
Sorry, paid work has gotten ever busier, and your previous email got lost. (Messages sent with "http://www.gryphel.com/c/feedback.html" may be less likely to get lost.)
Actually an SDL2 port of Mini vMac is something I was thinking of finding time for someday. Because my strategy for someday porting paid work to Android is to port Mini vMac to SDL2, which supports Android, and use that to make a native port of Mini vMac to Android in the same way I did the Cocoa port, and then compare the result to the existing Mini vMac Android port, all as way to become familiar with Android programming.
But there was no schedule to get started on this.
( ... quote of your plans to do SDL2 port ... )
That is very good news, and I'd be happy to try to assist as much as time permits.
(From now til the end of the year at least is extremely busy.)
( ... quote of questions about build process ... )
The Mini vMac build system will generate a set of source files for you, in unix format, with which you can use gcc and make. Probably you'd want to use "-api sdl" as a starting point, along with other options you desire.
Only after you complete the port to SDL2 should you start to think about merging it back into the DSK image. Actually you don't need to think about this at all, I'll do it. Just send your source version to me, or publish it somewhere that I can find it.
(I don't generally favor using email for communication about Mini vMac. It is sometime unreliable. And also I wouldn't saying anything in email that I wouldn't say to the general public, and being that careful of what I say is a waste of time if only one person will see it.)