I use to copy assembler code from PC Magazine and BYTE, and compile it with MS-DEBUG.EXE. That's the way early DOS utilities were distributed. I think there was a way in slightly earlier issues of BYTE to read in the assembler code with something like paper tape? (Not at all sure about that last one!)
Later we could download the assembler, and then the exe files.
I'd forgotten about, until I read this obit ... MS-DEBUG 1981 - 2009.