I might be ablt to help or even do it alone in some time down the road, but I though I just "throw these suggestions at you" - maybe someone who has a lot more experience with cross development of C and SDL programs that I have and would like to take a look and probably port one of these to KolibriOS.
1. Xerox Alto Simulator - salto. Using just C and SDL1. (YACC+LEX is just needed for aasm assembler and NOT needed for emulator!)
This is one of the first GUI computer developed at MIT.
2. OpenOberon - One of the workstation invented at ETH Zürich by Niklaus Wirth. This is using SDL2!
3. Lilith / Emulith - another machine invented by Niklaus Wirth at ETH Zürich. C using FLTK for GUI.
Link:http://pascal.hansotten.com/niklaus-wir ... h/emulith/