I've downloaded the source code of MSDOS 1.1 and 2.0, and want to compile MSDOS 1.1. I don't want to do it with an emulator (like DOSbox). How do I compile MSDOS 1.1 on Lubuntu 15.04?
You can not compile it because it is assembler code, i.e. code that is to be executed directly by the CPU. MS DOS 1.1 was just a re-brand of QDOS, an operating system developed for the Intel 8086 architecture. This means that MS DOS 1.1 can not be executed on different architectures.
You might be able to execute it with an assembler code interpreter able to emulate the Intel 8086, such as PCEmu or NASM (available from the Software Centre).
You can not compile it because it is assembler code, i.e. code that is to be executed directly by the CPU. MS DOS 1.1 was just a re-brand of QDOS, an operating system developed for the Intel 8086 architecture. This means that MS DOS 1.1 can not be executed on different architectures.
You might be able to execute it with an assembler code interpreter able to emulate the Intel 8086, such as PCEmu or NASM (available from the Software Centre).