Yet another indication that square dance callers are like programmers: here’s a comparison of text-command based OS’s to square dance calling.

DOS
“Disk Operating System” While the term DOS at one time referred to any disk-based operating system running on a computer, use of this term today is usually directed to the Microsoft DOS (MS-DOS) that was created to run on the Intel-based PCs. While Windows and the Macintosh OS are graphical user environments, DOS is text based. This means that users of DOS need to learn the specialized codes necessary to perform tasks. The concept is a little bit like calling a squaredance for your computer. Just don’t expect it to “do-si-do” when you type “DEL *.*”