Excel didn't really have its own C-compiler. Microsoft at that time had two (and a half) groups, Systems which included MS-DOS (and "languages"), and Applicatio

Excel didn't really have its own C-compiler. Microsoft at that time had two (and a half) groups, Systems which included MS-DOS (and "languages"), and Applications who were developing "office" applications. The apps group had its own compiler known as "cs" and organized around interpreted p-code which is smaller. This compiler was written for Multiplan and Word before Excel was even conceived. MS-DOS was written in assembly, and very stripped down and small, but office apps needed to be somewhat fatter with luxurious features so memory was an issue. Microsoft was working on a C compiler but wasn't selling it as a product (although, did they license Lattice C for awhile?) Ultimately, the cs compiler was added to Microsoft's C compiler as a p-code option. Ultimately ultimately people stopped caring about small memory and the utility of pcode went away.