Hello, I am expert for assembler x86/x64. I suppose this OS would be something like old MS-DOS? I see on screenshot textual mode OS probably 16-bit. As processor starts it is operating in 16 bit mode, then modern operating systems are changing mode to 32-bit and then to 64-bit if it is 64-bit operating system. What should this operating system do? There will be need to write own drivers-like code to work with disk, console, keyboard, mouse, etc. Depends what everything you wish this system can do. Some basic functions can accomplish BIOS. I suppose right it will be not multi-tasking OS? What is the purpose of this operating system? Please contact me with further details. Best Regards, Michal
PS: Price could be very various depending what everything this system should do. I do not know enough details now so my bid is as is and I would adjust it after I will know everything needed.